The present article deals with the development of a new statistical model (corrugated pore structure model: CPSM) simulating capillary condensation-evaporation hysteresis. The formulation of analytical expressions is based on probability principles, an adsorbed layer thickness correlation, Kelvin equation, and a random corrugated pore concept. When the model is fitted over experimental hysteresis loop data, the respective intrinsic pore size distribution (psd) and the corrugated pore parameter, N S (frequency of pore cross-sectional area variation), can be determined. The predictive potential of the CPSM was successfully tested in part 1 (this work) by generating hysteresis loops that reproduced those included in the IUPAC classification as well as those of novel nanoporous MCM-41 materials. CPSM evaluations of intrinsic pore size distributions have been more realistic and accurate than those deduced by applying the conventional methods (e.g., Roberts). The model has been further tested successfully in part 2 (Ind. Eng. Chem. Res. 2000, 39, 3764) by the fitting of experimental hysteresis data of various porous materials, e.g., HDS catalysts, anodic oxide films, lignite, montmorillonite, pillared clays, and MCM-41 mesopore molecular sieves.

A pilot-plant process has been developed based on an innovative laboratory-scale method for the recovery of scandium that exists in economically interesting concentrations in red mud, the main byproduct of alumina production. This method includes acid leaching of the red mud pulp, ion-exchange separation of scandium and lanthanides from the co-leached main elements such as iron, and subsequent liquid−liquid extraction of the eluate for further scandium purification and enrichment. In this work, experimental and theoretical investigation of the pilot-scale leaching process was performed. The following parameters were tested:  mode of agitation, solid-to-liquid ratio, acidity of the leachate, number of stages in the process, and pretreatment of red mud with concentrated acids in order to achieve optimum scandium recovery combined with low iron dissolution. Furthermore, by theoretical interpretation of the experimental data, a predictive correlation for the scandium leaching efficiency was developed.

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A performance assessment of the corrugated pore structure model (CPSM), developed in part 1 (Ind. Eng. Chem. Res. 2000, 39, 3747), is carried out through a simulation of experimental gas sorption hysteresis, covering all IUPAC versions and that of the novel MCM-41 materials. The materials studied are an anodic aluminum oxide film, HDS catalysts, montmorillonite, lignite, pillared clays, and MCM-41. CPSM evaluations of pore surface areas are consistent with the pertinent BET estimates while for partly microporous structures approach those obtained by the restricted adsorption BET variant. CPSM predictions of pore size distribution (psd) have been compared with those obtained by the Roberts method. In several examples, the latter method, when applied exclusively to condensation data, yielded psd's approaching the relevant CPSM distributions while, in other examples, by using evaporation data only, deduced psd's comparable to those yielded by the CPSM model. CPSM predictions are in partial agreement with the novel molecular simulation and the NLDFT theories. The CPSM model proved to be a simple, flexible, purely analytical model enabling meaningful predictions of intrinsic psd's and evaluations of a statistical pore shape parameter (N S ) related to pore structure tortuosity.

This study is a systematic literature review of geographical origin authentication by elemental analytical techniques. Authentication and certification of geographic origin of agri-food products is a useful tool toward the protection of the quality for products. The aim of this work was to map the current state of research in the area of agricultural products and food, identifying emerging fields to the geographical origin of products. The article is divided in three parts. The first part of the article deals with the analytical techniques applied in the food authentication. Special mention is made to elemental analysis and multiple isotope ratio. The second section focuses on statistically published data concerning published research for geographical origin authentication for the period 2015–2019. Specific results are presented inter alia: number of articles according to the type of product, articles according to the type of the analytical techniques, and others. The third part contains characteristic results from articles that were published in the period 2015–2019, on certification of geographical origin on specific agricultural products.

A corrugated pore structure model (CPSM−nitrogen)9 was employed to define a novel pore structure tortuosity concept. An empirical correlation is proposed for the prediction of tortuosity factors τCPSM as follows:  τCPSM = 1 + A[(D max,eff − D min,eff)/D mean](N S − 2) a . Constants A and a are adjustable parameters. The second factor reflects the influence of the intrinsic pore size distribution, and the third expresses the contribution of the nominal pore length parameter N S. The latter is, by definition, the number of pore segments forming a single corrugated pore of the CPSM pore configuration model and represents the frequency of pore cross section variation per unit length along a characteristic catalyst pellet dimension. The determination of N S and (D max,eff − D min , eff)/D mean is accomplished by fitting the CPSM model over the pertinent nitrogen sorption hysteresis data. Coefficients A and a were found to be A = 0.69 and a = 0.58 by applying the empirical correlation for two specified materials of known tortuosity. The tortuosity factors for an anodic aluminum oxide membrane, MCM-41 materials, dried lignite, a porous glass, and several HDS catalysts were predicted to be 2.60, 1.12−1.13, 1.33−2.79, 6.60, and 2.75−10.07, respectively. Such values approximate the literature data. Mercury porosimetry runs on the HDS catalysts showed a proportional increase in mercury entrapment with an increase in the corresponding τCPSM values. The tortuosity factor of lignite increases proportionally with the pore volume evolution. Further testing of the proposed correlation requires a rigorous analysis of diffusion phenomena, based on the CPSM pore structure configuration, combined with effective diffusivity measurements.

Seven mesoporous forms of silica were prepared by controlled and gradual functionalization of the original SiO2 surface with silano-(trimethoxy)-propyl-imidazole groups. The degree of surface functionalization was n ) 0.00, 0.23, 0.30, 0.40, 0.52, 0.60, and 0.85 and was controlled by previous knowledge of surface acidity, determined by temperature-programmed desorption of NH3. From N2 adsorption/desorption measurements, the specific surface area Sp (m 2 g -1 ), the specific pore volume Vp (cm 3 g -1 ), and the corresponding pore size distributions (PSDs) were determined. The connectivity c of the solids was also calculated according to the method of Seaton, and the dimensionality of capillary condensation Dcc was found using the thermodynamic method of Neimark. The increase of functionalization resulted in a linear drop of S p and Vp, and the maximum Dmax of the PSD and the full width at half-maximum, fwhm ∼ 2σ, of the distribution drop in a regular way whereas the ratio (Dmax/2σ) remains practically constant. The connectivity c also decreases from c ) 12.5 at n ) 0 to c ) 3 at n ) 0.60-0.85, presumably because of blocking of channels connecting various pores. The Dcc values decrease with increasing n values. Next, the co-called corrugated pore structure model, CPSM, was employed for the estimation of tortuosity τ of the porous solids and the simulation of the experimental adsorption/desorption isotherms. From those CPSM simulations, the corresponding specific surface area SCPSM (m 2 g -1 ), the specific pore volume VCPSM (cm 3 g -1 ), and the corresponding pore size distribution PSDCPSM were estimated. The tortuosity τ of the system drops with the degree of functionalization from τ ) 4.22 at n ) 0 to τ ) 3.37 at the initial functionalization (n ) 0.23) and subsequently remains practically constant at about τ ) 3.40 ( 0.10, for the same reasons which affect the connectivity, that is, blocking of various pore channels. The comparison between the parameters Vp and VCPSM is quite satisfactory. The SCPSM values appear systematically higher by 8-23% compared to the Sp ones. The dimensionality of capillary condensation Dcc is related to the variance 2σ of the PSD. The reasons and the limits of this relationship are discussed.

Sustainability, the circular economy, and the “greenhouse” effect have led the food packaging industry to use naturally available bio-compounds. The integration of such compounds in packaging films increases food safety and extends food shelf-life. The development of an active/antioxidant packaging film based on the widely commercially used low-density polyethylene, natural zeolite, and Thymol, a natural extract from thyme oil, is presented in this work. The obtained active films were characterized using X-Ray Diffraction, Fourier-Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Differential Scanning Calorimetry techniques. The tensile strength, water–oxygen barrier properties, and total antioxidant activity were measured. Low-density polyethylene incorporated with Thymol@Natural Zeolite at a proportion of 15 wt% was the most promising material and was used as film to wrap-up pork fillets. The thiobarbituric acid (TBA) method and heme iron measurements indicated a delayed lipids oxidation using this film. A linear correlation between the TBA method and heme iron values seems to be established, which could result in a fast method to determine the degree of lipid oxidation in pork fillets. Finally, a two-stage diffusion process during Thymol release was observed, and the values of the diffusion coefficient was 2.09 × 10−7 and 1.21 × 10−8 cm2/s for each stage. The applied pseudo-second sorption model provided a rate constant k2 = 0.01647 (s−1). These results indicate the strong potential of such films to be used as food packaging materials free of E-number preservatives.