Structural Properties Research Articles

Unveiling complex fault geometry and driving mechanisms: insights from a refined data processing and multiplet analysis of the 2010 Beni-Ilmane seismic sequence (NE Algeria)

Summary This paper offers a comprehensive re-analysis of the Beni-Ilmane 2010 seismic sequence, using a dataset that is 100 per cent larger than previous studies. This unprecedented sequence in Algeria features three mainshocks with magnitudes Mw 5.4, 5.1, and 5.1. Our approach involves high-precision relocation, which includes the development of a new 1D minimum velocity model, followed by a double-difference (DD) procedure and hierarchical clustering. We determined the focal mechanisms (FMs) for 128 key events and identified 21 multiplet groups using an average cross-correlation threshold of 0.8. Our analysis offers new insights into fault geometry and addresses ongoing debates, by proposing a seismotectonic model that reveals the activation of fourteen (14) fault segments during the sequence, in contrast to previous oversimplified models that suggested two or three faults. The computed stress field from the inversion of 128 FMs aligns with a tectonic loading force due to the convergence of the African and Eurasian plates. These findings highlight the complexity of the fault network in the study area and shed light on the role of strike-slip faults in shaping the thrust belt. We found a strong link between multiplet groups and fluid movement along the fault network. Analysis of the temporal history of these multiplet groups provides new insights into fluid dynamics timescales, with an estimated hydraulic diffusivity (D) of 0.36 m2/s suggesting a fluid pressure diffusion process. The observed expansion of the aftershock area with the logarithm of time and the existence of repeating earthquakes indicates, for the first time, an aseismic slip mechanism that adds an additional layer to the driven processes. In conclusion, our results suggest that the underlying mechanisms governing the BI-2010 seismic sequence involve a complex interplay of tectonic loading, coseismic stress transfer, fluid dynamics, and aseismic slip transients. We attempt to correlate our findings with various studies linking the structure, mechanics, and fluid flow properties of fault zones and fault systems. The activation of smaller fault segments potentially averted a larger quake, resulting in three moderate mainshocks and numerous aftershocks. This work not only enrich our understanding of seismic phenomena but also provides useful insights for seismic hazard assessment and risk mitigation strategies.

A review on advances in synthesis, composition, structural and microwave properties of U-type hexaferrites nanoparticles

A review on advances in synthesis, composition, structural and microwave properties of U-type hexaferrites nanoparticles

Quantum Sensing Unravels Antioxidant Efficacy Within PCL/Matrigel Skin Equivalents.

Skin equivalents (SE) that recapitulate biological and mechanical characteristics of the native tissue are promising platforms for assessing cosmetics and studying fundamental biological processes. Methods to achieve SEs with well-organized structure, and ideal biological and mechanical properties are limited. Here, the combination of melt electrowritten PCL scaffolds and cell-laden Matrigel to fabricate SE is described. The PCL scaffold provides ideal structural and mechanical properties, preventing deformation of the model. The model consists of a top layer for seeding keratinocytes to mimic the epidermis, and a bottom layer of Matrigel-based dermal compartment with fibroblasts. The compressive modulus and the biological properties after 3-day coculture indicate a close resemblance with the native skin. Using the SE, a testing system to study the damage caused by UVA irradiation and evaluate antioxidant efficacy is established. The effectiveness of Tea polyphenols (TPs) and L-ascorbic acid (Laa) is compared based on free radical generation. TPs are demonstrated to be more effective in downregulating free radical generation. Further, T1 relaxometry is used to detect the generation of free radicals at a single-cell level, which allows tracking of the same cell before and after UVA treatment.

Production and biological activities of exopolysaccharides synthesized by thermophilic bacilli isolated from hot springs in Türkiye.

Thermophilic bacteria able to produce exopolysaccharides (EPSs) have become attractive in recent years. EPSs synthesized by thermophiles are worth investigating due to their unexplored structural and biological properties. In this study, EPSs from thermophilic, Gram-positive bacterial isolates were purified and tested for their biological activities. A total of one hundred seven thermophilic bacteria were screened for their ability to produce exopolysaccharides. Nine isolates belonging to Geobacillus, Parageobacillus, Aeribacillus, and Anoxybacillus genera with highest EPS production were chosen, and purified EPSs (20, 61, 74, 76, 78, 89, 106, 134, and 261) were used for biological activity studies. EPS yields of selected thermophilic bacteria ranged between 117 and 419mg/L. Among the tested EPSs, 61, 106, and 261 showed antibacterial effect against E. faecalis JH2-2 at a final concentration of 1.5mg/mL. EPS samples had significantantioxidant capacity, especially EPS 134, with the highest DPPH radical scavenging activity of 100% at a concentration of 5mg/mL and the strongest reducing power.EPS 20 showed the highest lipid peroxidation inhibition effect at a rate of 31%. EPSs displayed weak alpha-amylase inhibition activity when compared with standard acarbose. The prebiotic indices of EPSs 20, 61, 76, 89, 134, and 261 were found to be higher than that of inulin, a representative prebiotic carbohydrate for all tested lactic acid bacteria in the study. All examined EPSs inhibited the biofilms formed by various bacteria depending on the test strain. Results indicated that thermophilic EPSs had remarkable antioxidant, prebiotic, and antibiofilm activities. Therefore, EPSs characterized in this study may have technological applications in health and food fields.

ZnO thin films co-doped with III-valence metals and halogens: theory and experiment

The efficiency of metal-halogen co-doping of ZnO thin films deposited by DC magnetron sputtering of ceramic targets has been studied theoretically and experimentally. The influence of deposition temperature (300 − 900 K range), ZnX2 pressure (10−10−1 atm), Me2O3 dopant concentration (10−3 − 10 mol %), and Zn pressure (10−14 − 10−6 atm) on the composition of ZnO − Me2O3 − ZnX2 − Zn (Me = Al, Ga, In; X = F, Cl, Br, I) systems has been analyzed theoretically. The surface migration velocity of oxides and halides is also estimated for a wide temperature range. According to the calculation results, the optimal deposition conditions have been recommended. ZnO thin films co-doped with Al+Cl, Ga+Cl, Ga+Br, Ga+I, and In+Cl were deposited using ZnO:Me:X ceramic targets sintered by chemical vapor transport based on halides. The influence of the stoichiometric deviation of ceramic targets, the concentration of halogens, and metal impurities on thin films’ electrical, structural, compositional, and optical properties has been investigated. It is shown that Ga+Cl+Zn co-doping is the most promising. This co-doping increases both the structural perfection of films (electron mobility) and doping efficiency by Ga (charge carrier concentration), reducing the resistivity of thin films by two times compared to the use of classical ZnO:Ga ceramic targets. The optimal stoichiometric deviation of ZnO:Me:X ceramics targets, corresponding to the highest electron mobility and figure of merit of thin films, has been recommended.

Effect of Sr substitution on the structural, dielectric and ferroelectric property of BaTiO3

We have performed a comprehensive study to explore the effect of Sr substitution on the structural and ferroelectric properties of BaTiO3(BTO) with compositions Ba1-xSrxTiO3for 0 ⩽x⩽ 1. The room temperature structural investigation inferred that the samples with compositionsx> 0.30 has cubic phase instead of tetragonal as for pristine BTO. The temperature dependent dielectric studies illustrate that all well-known three structural phase transitions of BTO are coming closer to each other and the cubic phase is shifted towards lower temperature with increasing Sr content. The frequency dependent dielectric measurements show that there exists the mesoscopic subdomain, whose relaxation time decreases with increasing Sr concentration. The Sr substitution enhanced the ferroelectric properties and maximum remnant polarization at room temperature is observed for 20% Sr substituted sample. The frequency dependent dielectric measurements illustrate the relaxation which could be due to the mesoscopic subdomain, and its relaxation time decreases with increasing Sr concentration. The frequency dependentP-Emeasurements at room temperature infer that for 30% Sr substituted sample, the ferroelectric domain switching is dominated by the rate of nucleation whereas in other compositions forx< 0.3, it is governed by the domain wall speed. The Raman measurements infer the rearrangement of the domain configuration with Sr substitution. Modification in the intensity of the E(TO4) and A(TO3) Raman modes with electric field is also observed for 30% Sr substituted sample and the origin of this is also discussed.

A Comparative Study on Structural, Crystallographic and Microstructural Properties of Nano-TiO2 Intermixed and Surface-Coated Portland Cement Mortars

A Comparative Study on Structural, Crystallographic and Microstructural Properties of Nano-TiO2 Intermixed and Surface-Coated Portland Cement Mortars

Production and technical performance of scrimber composite manufactured from industrial low-value wood for structural applications

Development of scrimber composites and other engineered wood products from low-value wood and wood waste provides an effective opportunity to preserve natural resources, minimize waste, and innovate the production of higher-performance, environment-friendly construction materials. In this study, peeler cores, which are the center of poplar logs remaining after the peeling process in the veneer production, were utilized to develop scrimber composites. This study investigated the effects of different resins, including phenol-formaldehyde (PF) and urea formaldehyde (UF), as well as hydrothermal treatments at various temperatures (60 °C and 130 °C), on the physical and mechanical properties of the scrimber composites. Chemical changes in wood components and morphological changes in wood cell walls resulting from hydrothermal treatment were analyzed using Fourier transform infrared spectroscopy and scanning electron microscopy. To clarify how resin type and hydrothermal treatment affect structural performance, several physical and mechanical properties of scrimber composites, including thickness swelling, water absorption, internal bond strength, bending modulus of elasticity, and modulus of rupture, were measured. The test results revealed that hydrothermally treated wood scrims at 130 °C, when bonded with PF resin, produced scrimber composites with superior structural performance.

EXPLORING THE STRUCTURAL AND ELECTRONIC CHARACTERISTICS OF AMORPHOUS Ge – Te - In MATERIAL THROUGH AB INITIO METHODS

This study employs density functional theory (DFT) and molecular dynamics to meticulously investigate the structural and electronic properties of ternary chalcogenide compounds, specifically (GeTe4 ) 1-x Inx, and (GeTe5 )1-x Inx across a range of compositions ( x = 0, 5, 10, 15, 20 at %). Utilizing the local density approximation within the framework of first-principles calculations, we comprehensively analyze the pair correlation function, static structural factor, electronic density of states, and electronic band gap energy. Our results reveal a notable decrease in the energy band gap of Germanium-Tellurium with the incorporation of Indium atoms. The structural changes observed in the Ge-Te matrix with Indium doping, as evidenced by the changes in the pair correlation function and static structure factor, are consistent with and supportive of the observed decrease in the band gap energy. This phenomenon is primarilyattributed to the significant contribution of Indium atoms to the conduction band edge, offering new insights into the material’s electronic behaviour.

Ionomeric Binders for High Temperature Proton Exchange Membrane Fuel Cells.

High-temperature proton exchange membrane fuel cell (HT-PEMFC) based on phosphoric acid doped polybenzimidazole membrane (PBI/PA) operating at 120-200 °C can provide insensitivity to carbon monoxide (CO) and simplified managements of water and heat and thus attract significant global attention. However, one significant drawback is its low utilization of precious metal catalysts resulted from the PA poisoning and inefficient three-phase boundary. Studies of binder materials in catalyst layers for HT-PEMFC are gradually emerging and there are few literature reviews on this important topic. The purpose of this review is to describe the various types of binders based on their molecular structure and electrochemical properties, with particular emphasis on catalyst layer for fuel cells. Importantly, this review provides a better understanding of relationship between fuel cell performance and the gas permeability and conductivity of different binders. Then, future directions of research and development in binder materials of HT-PEMFC are pointed out.

Expressing Partial Order-Preserving Transformations as Products of Nilpotents

Let S be a semigroup with zero, then an element a∈S is called nilpotent, if there exists a positive integer n such that . In the partial transformation semigroup on , where is a non-empty set, denoted by , the empty map is the zero of . Further, nilpotency is a structural property of fundamental importance which arises in many situations, for instance in linear algebra, we have nilpotent matrices and much more in other branches of mathematics. In this study, we will investigate, some elements of semigroups of partial one-to-one order-preserving transformations (denoted by ) and partial order-preserving transformations (denoted by ), and some basic properties of nilpotent transformations. We have studied certain properties of nilpotent elements in , symmetric inverse semigroup, where is finite and infinite, certain properties of nilpotent elements in , descriptions of the elements of 〈N〉, where N is the set of nilpotents of and we used the same letter N to denote that of , and used them to establish the following results, in this paper (that is, we have used the knowledge that we have acquired to establish the following results): - a partial ono-to-one order-preserving transformation , has from 1 to fixed, and there is an upper jump of length two(2) between and , and lower jumps of length one(1) and one(1), immediately after , can be expressed as a product of three nilpotents. – a partial one-to-one order-preserving transformation , has from 1 to fixed, and there is an upper jump of length three (3) between and and lower jumps of length two (2) and one (1), immediately after , can be expressed as a product of fewer than three nilpotents. – a partial order-preserving transformation , has from 1 to fixed, but belongs to , and there is an upper jump of length two(2) between and , and lower jumps of length two(2) and one(1), immediately after , cannot be expressed as a product of fewer than three nilpotents. – a partial order-preserving transformation , has from 1 to fixed, but belongs to , and there is an upper jump of length three (3) between and , and lower jumps of length three (3) and one (1), immediately after n-5, can be expressed as a product of fewer than three nilpotents. – a transformation , partial transformation semigroup, is not nilpotent if and only if the graph of the transformation has a loop, and - a transformation , partial one-to-one transformation semigroup, which has a nilpotent path and a permutation part is not nilpotent

Characterization of 2-phenanthroate:CoA ligase from the sulfate-reducing, phenanthrene-degrading enrichment culture TRIP.

Polycyclic aromatic hydrocarbons (PAHs) constitute a class of very toxic and persistent pollutants in the environment. However, the anaerobic degradation of three-ring PAHs such as phenanthrene is barely investigated. The initial degradation step starts with a carboxylation followed by a CoA‑thioesterification reaction performed by an aryl-CoA ligase. The formation of a CoA-thioester is an important step in the degradation pathway of aromatic compounds because the CoA-ester is needed for all downstream biochemical reactions in the pathway. Furthermore, we provide biochemical proof for the identification of the first genes for anaerobic phenanthrene degradation. Results presented here provide information about the biochemical and structural properties of the purified 2‑phenanthroate:CoA ligase and expand our knowledge of aryl-CoA ligases.

Effect of the Ratio of Soluble and Insoluble Dietary Fiber from Rice Bran with Extrusion Cooking Treatment on Pasting, Thermal, and Structural Properties of Rice Starch Gel

AbstractThis study aims to investigate the effect of different ratios of soluble and insoluble dietary fiber (0/100, 25/75, 40/60, 55/45, 70/30, 85/15, 100/0) in rice bran treated with or without extrusion cooking on the physicochemical and structural properties of rice starch. As the ratio of soluble dietary fiber (SDF) increases, the PV (peak viscosity), FV (final viscosity), SB (setback value), and BD (breakdown value) of starch are significantly decreased, indicating that a higher SDF ratio can delay the short‐term retrogradation of starch. Compared with the unextruded rice bran SDF/IDF starch gel, the content of weak bond water and free water in the extruded rice bran SDF/IDF starch gel is higher while the content of strong bond water in the starch gel is lower at the same SDF/IDF ratio. Meanwhile, for the results X‐ray diffraction (XRD) and fourier transform infrared spectrum (FTIR), the rice starch with the extruded rice bran SDF/IDF ratio of 25:75 shows the lowest relative crystallinity of 3.48% and the lowest peak to height ratio of FTIR (1047 cm−1/1022 cm−1) of 1.0746, suggesting that the inhibition effect on rice starch retrogradation is better. This may be beneficial for the utilization of different ratios of SDF/IDF from extruded rice bran and physicochemical properties improvement of rice starch gel.

Pressure‐Enhanced Superconductivity and Structural Phase Transition in Layered Sn4P3

High pressure provides a unique tuning method depending on structure modulation to explore the structure–property relationship. Herein, the pressure‐induced structural phase transformation and enhanced superconductivity in a layered binary phosphide Sn4P3 are reported. Comprehensive measurements using in situ synchrotron X‐Ray diffraction and Raman spectroscopy reveal a structural phase transition with mild distortion of SnP3 building blocks and interlayer shrinkage under high pressure. This differs from a conventional trigonal SnAs(P)3 to square SnAs(P)4 topotactic transition in SnAs(P)‐based compound. Through this structure reconstruction under high pressure, electron distribution has been reorganized and phonons have softened, facilitating a high superconducting temperature (Tc) value of 7.8 K at 34.9 GPa, which is almost six times higher than its ambient value. The study introduces a new transition route in layered SnAs/SnP‐based intermetallic materials and provides insight into the structural and electronic changes under high pressure for Sn4P3.

Exploring the influence of Zn impurities on the structural, optical, and H2 sensor properties of ultrasonic spray pyrolysis-grown MgO thin films

Magnesium oxide (MgO) thin films, both pure and zinc (Zn) doped, were fabricated on soda lime glass substrates using ultrasonic spray pyrolysis. Zn was introduced at concentrations of 0.5 %, 1 %, 2 %, 4 %, and 8 %. The effects of these doping levels on the films' structural, morphological, optical, and H2 gas sensing properties were studied using XRD, SEM, EDAX, UV–vis spectroscopy, PL spectroscopy, gas sensing measurements, and XPS. The films showed a cubic crystal structure without secondary phases, and grain sizes generally decreased with doping. Morphological changes in nanocrystal shapes were noted due to impurities. Optimal doping enhanced MgO's absorbance, with a slight increase in bandgap. The PL spectra showed increased luminescent emissions with higher doping, due to defects from Zn ions. Pure films were responsive to H2 gas, while Zn-doped samples showed weaker responses. The XPS confirmed the expected chemical compositions.

Immunoinformatic approach to design an efficient multi-epitope peptide vaccine against melanoma.

Melanoma is known to be the most hazardous and life-threatening type of skin cancer. Although numerous treatments have been authorized in recent years, they often result in severe side effects and may not fully cure the disease. To combat this issue, immunotherapy has emerged as a promising approach for the prevention and treatment of melanoma. Specifically, the use of epitope melanoma vaccine, a subset of immunotherapy, has recently gained attention. The aim of this study was to create a multi-epitope melanoma vaccine using immunoinformatic methods. Two well-known antigens, NYESO-1 and MAGE-C2, were selected due to their strong immunogenicity and high expression in melanoma. To enhance the immunogenicity of the peptide vaccine, Brucella cell-surface protein 31 (BCSP31), the G5 domain of resuscitation-promoting factor B (RpfB) adjuvants, and the helper epitope of pan HLADR-binding epitope (PADRE) were incorporated to vaccine construct. These different segments were connected with suitable linkers and the resulting vaccine structure was evaluated for its physicochemical, structural, and immunological properties using computational tools. The designed vaccine was found to have satisfactory allergenicity, antigenicity, and physicochemical parameters. Additionally, a high-quality tertiary structure of the vaccine was achieved through modeling, refinement, and validation. Docking and molecular dynamics studies showed that the vaccine had a stable and appropriate interaction with the cognate TLR2 and TLR4 receptors during the simulation period. Finally, in silico immune simulation analysis revealed a significant increase in the levels of helper and cytotoxic T cells, as well as the cytokines interferon-gamma and interleukin-2, after repeated exposure to the melanoma vaccine. These results suggest that the designed vaccine has the potential to be an effective therapeutic option for melanoma. However, additional in vitro and in vivo validations are crucial to assess real-world efficacy and safety.

The effect of differing Y concentrations on the evolution of the structure and mechanical properties of FeCrAl alloy

The influence of different Y concentrations on the evolution of the structural and mechanical properties of FeCrAl alloys is investigated in this work. The ingot casting process was used to produce alloys with Y mass fractions of 0%, 0.03%, and 0.25%, respectively. They were then annealed for 15 min at 850°C, 950°C, and 1050°C before being quenched by water to room temperature. Microstructure and mechanical properties were analyzed using OM, EPMA, EBSD, and tensile tests. The addition of 0.03% Y to FeCrAl alloy and annealing at 850°C resulted in the greatest overall performance of the alloy. This had a tensile strength of 635.62 MPa, yield strength of 465.48 MPa, and elongation of 27.04%. With an increase in Y concentration or annealing temperature, the tensile, yield, and elongation properties decrease. This phenomenon can be attributed to the incorporation of Y, which creates a fine Y-rich second phase in the alloy. These phases act as heterogeneous nuclei, pinning the grains during solidification, effectively reducing grain growth and refining the grains. Grain refinement and an increase in the number of grain boundaries hinder dislocation movement, thereby enhancing the alloy's tensile and yield strength. Simultaneously, this prevents the disappearance of α-fiber textures and the creation of γ-fiber textures during recrystallization and reduces the strength of the γ-fiber textures in the alloy microstructure. However, as the annealing temperature increases, microstructure grain growth and the number of grain boundaries decrease. Moreover, higher Y concentrations result in the formation of large, striated Fe-Y phases, which impair the forming properties of the alloy and consequently reduce its tensile properties. Therefore, future research should focus on effectively avoiding the formation of coarse second phases in the microstructure of FeCrAl alloy to enhance its overall performance.

The Impact of Bromine Surface Doping on the Structural, Optical, and Morphological Properties of Bismuth‐Based Perovskite Film as a Light‐Absorber in Perovskite Solar Cells

Bismuth‐based perovskite materials have concerned significant attention due to their low‐toxic and stable properties. However, achieving smooth and dense thin films for the preferential growth of bismuth‐based perovskite along the c‐axis, which is conducive to the preparation of solar cells, is challenging. Therefore, using halogen atoms to partially replace iodine atoms and constrain anisotropic growth has been shown to be an effective method for obtaining high‐quality perovskite films. Herein, Br doping with varying concentrations is used to treat bismuth‐based perovskite films with larger and denser grains compared to those without doping. When a small amount of Br ions is doped, the surface of the perovskite layer becomes more uniform, significantly improving the compactness of the perovskite film. Additionally, proper Br doping can reduce internal defects in the films, effectively inhibiting nonradiative recombination, enhancing light absorption, and increasing carrier lifetime. The optimal power conversion efficiency of Br‐doped bismuth halide perovskite solar cells is found to be 0.136%, compared to 0.087% for pristine devices.

Impact of PCLNPG Nanopolymeric Additive on the Surface and Structural Properties of PPSU Ultrafiltration Membranes for Enhanced Protein Rejection

This research explored the use of a partially cross-linked graft copolymer (PCLNPG) as an innovative nanopolymer pore-forming agent to enhance polyphenylsulfone (PPSU) membranes for protein separation applications. The study systematically examined the impact of incorporating PCLNPG at varying concentrations on the morphological and surface properties of PPSU membranes. A thorough characterization of the resulting PPSU-PCLNPG membranes was performed, focusing on changes in morphology, water affinity, porosity, pore size, and pore size distribution. The experimental findings demonstrated that the use of PCLNPG led to a significantly more porous structure, as confirmed by SEM analysis, with notable increases in porosity and pore size (nearly double). Additionally, the hydrophilicity of the PPSU membrane was remarkably enhanced. Performance evaluations revealed a substantial improvement in pure water flux, with the flux nearly tripling. The BSA retention was directly correlated with the concentration of the PCLNPG pore former for a loading range of 0.25–0.75 wt.%. The incorporation of PCLNPG also reduced the membrane fouling propensity by reducing both cake layer resistance (Rc) and pore plugging resistance (Rp). These results underscore the potential of PCLNPG-PPSU membranes for wastewater reclamation and nutrient recovery applications.

Catalyst Accessibility and Acidity in the Hydrocracking of HDPE: A Comparative Study of H-USY, H-ZSM-5, and MCM-41 Modified with Ga and Al.

Plastic pollution is a critical environmental issue due to the widespread use of plastic materials and their long degradation time. Hydrocracking (HDC) offers a promising solution to manage plastic waste by converting it into valuable products, namely chemicals or fuels. This work aims to investigates the effect of catalyst accessibility and acidity on the HDC reaction of high density polyethylene (HDPE). Therefore, a variety of materials with significant differences in both textural and acidic properties were tested as catalysts. These include H-USY and H-ZSM.5 zeolites with various Si/Al molar ratios (H-USY: Si/Al = 2.9, 15, 30 and 40; H-ZSM-5: Si/Al = 11.5, 40, 500) and mesostructured MCM-41 materials modified with Ga and Al, also with different Si/metal ratios (Si/Al = 16 and 30; Si/Ga = 63 and 82). Thermogravimetric analysis under hydrogen atmosphere was used as a preliminary screening tool to evaluate the potential of the various catalysts for this application in terms of energy requirements. In addition, batch autoclave reactor experiments (T = 300 °C, PH2 = 20 bar, t = 60 min) were conducted to obtain further information on conversion, product yields and product distribution for the most promising systems. The results show that the catalytic performance in HDPE hydrocracking is determined by a balance between the acidity of the catalyst and its structural accessibility. Accordingly, for catalyst series where the structural and textural properties do not vary with the Si/Al ratio, there is a clear correlation of the HDPE degradation temperature and of the HDPE conversion with the Si/metal ratio (which relates to the acidic properties). In contrast, for catalyst series where the structural and textural properties vary with the Si/Al ratio, no consistent trend is observed and the catalytic performance is determined by a balance between the acidic and textural properties. The product distribution was also found to be influenced by the physical and chemical properties of the catalyst. Catalysts with strong acidity and smaller pores were observed to favor the formation of lighter hydrocarbons. In addition to the textural and acidic properties of the catalyst, the role of coke formation should not be neglected to ensure a comprehensive analysis of the catalytic performance.