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Ni0.4Cd0.3Zn0.3Fe2O4 ferrites have been prepared through the use of sol-gel method at 900 °C and 1100 °C. Rietveld refinements of XRD patterns indicate that the prepared samples crystallize in the cubic spinel structure. Lattice constant and grain size are found to increase with sintering temperature. Magnetic measurements show that the maximum magnetization (Ms) rises, whereas both coercivity (Hc) and remanence (Mr) decrease when increasing the sintering temperature. Frequency and temperature dependence of electrical conductivity, electrical modulus, and electrical impedance have been studied using impedance spectroscopy technique. As the sintering temperature increases, the conductivity of the samples increases. The variation of imaginary part of modulus (M″) displays the presence of an electrical relaxation phenomenon and non-Debye nature. Nyquist representations have been analyzed using an electrical equivalent circuit. The obtained results reveal that the conduction mechanism of the samples is achieved basically of the grain boundary contribution.

In this article, a theoretical study was performed in order to elucidate the adsorption mechanism of methylene blue (MB) on Cortaderia selloana flower spikes (FSs) and on Cortaderia selloana flower spikes derived carbon fibers (CFs). For this objective, the Hill model developed using grand canonical ensemble was successfully applied. This model represents the general case of Langmuir model assuming that the receptor sites of CFs and FSs accepts a variable number of MB molecules and is defined by the number of molecules captured per adsorbent site (n). Based on the model parameters, the MB adsorption geometry was described at different temperatures indicating that the MB molecules were fixed by an angled position on the investigated adsorbents. The elucidation of the adsorption capacity showed that CFs was more effective for removing MB from wastewater than FSs. This behavior was detailed and corroborated by an energetic investigation. Moreover, the adsorption energy varies from 22.187 to 25.378 kJ mol−1 for FSs and from 24.503 to 27.412 kJ mol−1 for the CFs reflecting a physisorption process. Interestingly, and based on this energetic investigation, it was deduced that the adsorption mechanism of MB was endothermic. Excellent correlation between the number of molecules captured by the receptor site, the adsorption capacity, and the adsorption energy was observed.

The statistical physics approach has been well studied by our research team for liquid and gaseous adsorption systems. This treatment is based on the grand canonical partition function to give new interpretations of the adsorption process at molecular level for chemical senses: olfaction and taste. This work represents a contribution to understand the olfaction mechanism of four of enantiomeric terpenes by applying a statistical physics treatment that allows giving a physico-chemical meaning to parameters involved in the analytical model. It is possible to estimate the number of adsorbed molecules per site, the anchorage number, the receptor density, the concentration at half saturation and the molar adsorption energy. Through this selection of the best fitting model and through fitted values of these parameters, we showed that the adsorption of carvone and limonene enantiomers is not a multilayer process but a monolayer monosite process (monolayer adsorption model with identical and independent sites (n ≠ 1)). The physico-chemical model parameters can be used for the energetic characterization of the interactions between the carvone and the limonene enantiomers and the human olfactory receptor OR1A1 and the determination of an olfactory band of order of 14 kJ/mol, 7 kJ/mol, 9 kJ/mol, 8 kJ/mol for (R)-(−)-carvone, (S)-(+)-carvone, (R)-(+)-limonene and (S)-(−)-limonene, respectively, through the determination of the adsorption energy values and the adsorption energy distributions (AEDs). Thanks to the grand canonical formalism in statistical physics, the negative values of the Gibbs free enthalpy indicate that the adsorption process of the four enantiomeric terpenes onto the human olfactory receptor OR1A1 was spontaneous. The exothermic adsorption mechanism involved in the olfactory perception was explained via the negative values of the internal energy.

Steric and energetic characterizations were performed for the adsorption of eugenol (EG), vanillin and ethyl vanillin (EV) onto the mouse eugenol olfactory receptor mOR-EG by using a proposed model expression established by statistical physics methods. We started with a modeling of dose-response curves. The calculated curves fit well the experimental data and the physico-chemical model parameters can be used for the characterization of the interactions between the eugenol, vanillin and ethyl vanillin molecules and the mouse eugenol receptor and the determination of the olfactory band for these three odorant molecules through the determination of the adsorption energy values and the adsorption energy distributions. Furthermore, thermodynamic functions of the odorant adsorption such as the configurational entropy, Gibbs free enthalpy and internal energy were calculated and their negative values indicate that the adsorption process included in the olfaction mechanism was exothermic and spontaneous nature.

The Mg 50 Ni 45 Cr 5 alloy for hydrogen storage is prepared by mechanical alloying. First, using the X-ray diffraction (XRD) and the scanning electron microscopy (SEM) we examine the morphology and the structure of the substrate. The obtained results highlight the effectiveness of this alloy in loading hydrogen as it is a nanocrystalline and a ductile one. Second, we attempt to justify these expectations using the statistical physic, precisely the model monolayer with two levels of energy, in modeling a hydrogen absorption and desorption isotherms on Mg 50 Ni 45 Cr 5 alloy at four temperatures T = 275 K, T = 300 K, T = 325 K and T = 350 K. The model has six physicochemical parameters deduced from the fitting of the isotherms, they are divided by two categories of steric and energetic parameters. Thanks to these parameters we compare the absorption and desorption processes, in order to highlight the hysteresis phenomenon encountered during the hydrogen sorption.

We have investigated the correlation between magnetocaloric and electrical properties of La0.47Pr0.2Pb0.33MnO3 perovskite prepared using the sol–gel method. Rietveld analysis of X-ray diffr...

Based on statistical physics elements, the equilibrium adsorption of diclofenac (DFC) and nimesulide (NM) on activated carbon was analyzed by a multilayer model with saturation. The paper aimed to describe experimentally and theoretically the adsorption process and study the effect of adsorbate size using the model parameters. From numerical simulation, the number of molecules per site showed that the adsorbate molecules (DFC and NM) were mostly anchored in both sides of the pore walls. The receptor sites density increase suggested that additional sites appeared during the process, to participate in DFC and NM adsorption. The description of the adsorption energy behavior indicated that the process was physisorption. Finally, by a model parameters correlation, the size effect of the adsorbate was deduced indicating that the molecule dimension has a negligible effect on the DFC and NM adsorption.

The results of structural, magnetic, critical, and magnetocaloric characterizations of La0.6Ca0.2Na0.2MnO3 perovskite have been reported. XRD analysis of the sample synthesized using sol-gel method shows good crystallization in the $$ R\overline{3}c $$ rhombohedral structure. From M(T) curve, a second-order ferromagnetic-paramagnetic (FM-PM) phase transition appears at the Curie temperature (TC) around 275 K. Critical exponents (β, γ, and δ) have been evaluated using different techniques such as modified Arrott plots (MAP), Kouvel-Fisher (KF) method, and critical isotherm (CI). We found that the critical exponents of the prepared sample agree well with those of the mean-field model. We have also estimated the magnetic entropy change (−ΔSM) and relative cooling power (RCP) for the sample which obey power laws as −∆SM = a(μ0H)n and RCP = A(μ0H)N, respectively. ΔSM and RCP values were relatively higher, making the sample promising candidate for magnetic refrigeration technology. The estimated values of the magnetic ordering parameters (n and N) are used to confirm the reliability of the evaluated critical exponent.

In this paper, an adsorption modeling has been presented to describe the interactions of a binary mixture of l-muscone and d-muscone with the mouse muscone receptor MOR215-1. The formulation of the 2-dimensional monolayer models with identical and two types of sites for the perceived response of odor binary mixture odor are based on statistical physics and some theoretical hypothesis, in order to model pure and binary mixture dose-response curves. Thanks to the grand canonical ensemble of statistical physics, some pertinent physico-chemical parameters describing the adsorption process were introduced in the analytical model expressions. The results showed a high correlation of the 2-dimensional monolayer model using two types of sites with binary mixture of l-muscone and d-muscone response curve. In this model, six physico-chemical parameters derived from the fitting of the experimental data by a numerical simulation were discussed. Furthermore, these statistical physics models include physico-chemical parameters specific to the respective effects of each compound in the binary mixture, which may help to clarify the inhibitory effects that are often seen in l-muscone and d-muscone mixture through the determination of the involved new steric parameters. In addition, the calculation of the molar adsorption energies showed that the two muscone enantiomers and their racemic were physisorbed onto cell surface neurons.

Using the grand canonical ensemble in statistical physics, a hydrogen absorption and desorption isotherms on LaNi4.85 Al0.15 alloy have been modeled by a monolayer model with two level of energy. The model has six physicochemical parameters which are deduced from the fitting of the isotherms at three temperatures T = 298 K, T = 303 K and T = 313 K. These parameters were used to better understand and compare between the absorption and desorption phenomena. A macroscopic study is achieved through thermodynamic functions as the internal energy, the entropy, the free enthalpy, the chemical potential, the enthalpy, and the free energy. We proved the coexistence of the α and β phases during absorption process.

Modeling of absorption and desorption isotherms of hydrogen on LaNi4.85Al0.15 alloy at 298 K, 303 K and 313 K has been achieved through the use of grand canonical ensemble in statistical physics. In fact, a monolayer model with two levels of energy has been adopted to better fit the experimental data. Besides, six physicochemical parameters have been used to better describe the absorption and desorption processes from the point of view of α and β phases. These parameters are divided into two types. The first type of parameters contains four main parameters, namely the number of atoms per site, nα and nβ, and the densities of hydrogen receptor sites Nmα as well as Nmβ. The second type of parameters are mainly the two energetic parameters Pα and Pβ which respectively refer to the pressures at half saturations for the α phase and the β phase. Thanks to these steric and energetic parameters, we could compare the absorption and desorption processes to highlight the evolution of these parameters during hysteresis encountered in the desorption isotherms.

The olfactory response curves of muscone enantiomers on the mouse muscone receptor MOR215-1 modeling by a statistical physics treatment led us to better understand the olfactory phenomenon. Our objective in this modeling is to select an adequate model that presents a significant correlation with the olfactory response curves. The application of the grand canonical ensemble in statistical thermodynamics introduces some physico-chemical parameters in the theoretical model which allows to attain an expression of the single olfactory response Rsin. Fitting results showed that the muscone enantiomers ( l -muscone and d -muscone) followed an adsorption model with one monolayer onto identical sites. The calculation of the molar adsorption energy showed that the two muscone enantiomers were physisorbed onto cell surface neurons. Then, the configurational entropy which gave an idea about order and disorder, was calculated according to the appropriate model.

In this work, statistical physics treatment has been employed to understand the olfaction mechanism through the study of the dose-olfactory response of putative adsorption process of key food odorants onto the human olfactory receptor OR2W1. This is in order to obtain new steric and energetic characterizations at the molecular level of this chemical sense system. Three models have been proposed: a monolayer, a double layer and a three layers model. The monolayer model with identical and independent receptor sites has been chosen as an appropriate one to present a good correlation with the experimental dose-response curves. Indeed, the numerical values of the three fitted parameters (RM, n, C1/2) are used to characterize the size of the human olfactory receptor binding sites and the interactions between eight key food odorants i.e., (R)-(−)-carvone, (S)-(−)-limonene, (R)-(+)-limonene, 2-phenylethanthiol, 3-mercaptohexyl acetate, methyl cinnamate, cinnamyl acetate and 2-phenylethyl acetate and OR2W1 through the receptor site size distribution (RSD) and to determine an olfactory band of these odorants through the determination of the adsorption energy values and the adsorption energy distributions (AEDs).

In the biosensor system, olfactory receptor sites could be activated by odorant molecules and then the biological interactions are converted into electrical signals by a signal transduction cascade that leads the toopening of ion channels, generating a current that leads into the cilia and depolarizes the membrane. The aim of this paper is to present a new investigation that allows determining the olfactory band using a monolayer adsorption with identical sites modeling which may also describe the static and the dynamic sensitivities through the expression of the olfactory response. Moreover, knowing the size of receptor site in olfactory sensory neurons provides valuable information about the relationship between molecular structure and biological activity. The determination of microreceptors and mesoreceptors is mostly carried out via physical adsorption and the radius is calculated using the Kelvin equation. The mean values of radius obtained from the maximum of the receptor size distributions peaks are 4 nm for l-muscone and 6 nm for d-muscone.

The Mg50Ni45Ti5 alloy for the hydrogen storage is prepared by mechanical alloying. The structure and the morphology of the alloy are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). These techniques esteemed that this alloy is a good candidate for hydrogen storage, since it is both nanocristallin and dsuctile. This is confirmed by the modeling of the hydrogen equilibrium pressure-composition-temperature (PCT) relationships for this alloy. These isotherms were experimentally generated for three temperatures 313 K, 327 K and 340 K and modeled through the statistical physics using the monolayer model with two energies levels. Energetic, steric and thermodynamic studies were released thanks to this model which proved the efficiency and the security of this alloy to the storage of hydrogen.