X-ray Microtomography Analysis Research Articles

X-ray Microtomography Analysis of Integrated Crop–Livestock Production’s Impact on Soil Pore Architecture

X-ray Microtomography Analysis of Integrated Crop–Livestock Production’s Impact on Soil Pore Architecture

Dual-species biofilm of Streptococcus mutans and Candida albicans produces subsurface caries lesions on bovine enamel

ObjectivesTo develop a protocol for forming subsurface caries lesions on bovine enamel by dual-species biofilms of Streptococcus mutans and Candida albicans in vitro. DesignBiofilms were grown on bovine enamel specimens in artificial saliva (AS) for seven days. After 24 h of formation, the AS was supplemented or not with fluoride (F) using sodium fluoride (0.005 or 0.008 ppm F), and the biofilms were exposed or not to a 20 % sucrose solution (reproducing a cariogenic challenge) once/day. On the seventh day, the biofilms were harvested and had their extracellular polysaccharides (EPS) and inorganic components analyzed. The specimens were subjected to computed X-ray microtomography analysis to determine their mineral concentration. Data were compared using two-way analyses of variance, followed by Fisher’s LSD or Student–Newman–Keuls tests (p < 0.05). ResultsBiofilms exposed to the cariogenic challenge had significantly higher EPS concentrations than those not exposed, regardless of the presence of F. For biofilms grown with 0.008 ppm F, those exposed to the cariogenic challenge had lower F levels than those not exposed. For biofilms exposed to the cariogenic challenge, those grown with 0.008 ppm F had lower lesion depths and integrated mineral loss, and higher outer layers than those grown without F. ConclusionsThe dual biofilm model assessed was able to create subsurface caries lesions in bovine enamel in vitro, which was influenced by the presence of F in the culture medium and exposure to sucrose.

Gas-assisted high-moisture extrusion of soy-based meat analogues: Impacts of nitrogen pressure and cooling die temperature on density, texture and microstructure

This study explored the potential of a novel gas-assisted high-moisture extrusion cooking technique to improve the physical quality of meat analogues. Extrusion was performed as a full factorial design at three long cooling die temperatures (DT) (35, 50 and 65 °C) and three nitrogen gas injection pressures (GP) (0, 1 and 2.5 bar). The lowest meat analogue density was observed for the meat analogues produced at the lowest DT and highest GP combination. At the lowest DT, gas injection substantially decreased meat analogue hardness, chewiness and gumminess. X-ray microtomography analyses for meat analogues produced at 2.5 bar gas injection pressure revealed that DT significantly affected bubble sizes with larger and more diverse bubbles in the meat analogues produced at the lowest DT. These microstructural variations indicate that gas-assisted high-moisture extrusion cooking can be fine-tuned to improve the texture and, thus, sensory properties of meat analogues. Industrial relevanceHigh-moisture extrusion cooking is widely used for industrial-scale production of plant-based meat analogues. Manufacturing meat analogues with desired hardness and chewiness without detrimental effects on other characteristics such as color and degree of texturization is still quite challenging using conventional high-moisture extrusion cooking. Gas-assisted high-moisture extrusion cooking, when fine-tuned, has great potential in manipulating end-product texture and color without negatively impacting the degree of protein texturization.

Enhancement of the Mechanical Performance of Glass-Fibre-Reinforced Composites through the Infusion Process of a Thermoplastic Recyclable Resin.

Mechanical testing of glass-fibre-reinforced composite (GFRP) plates made of twill fabric and a thermoplastic recyclable infusion resin is presented. The considered thermoplastic resin, ELIUM®, is made of poly-methylmethacrylate and can be infused with properly tuned vacuum techniques, in the same manner as all liquid resin. Tensile, flexural, and drop-dart impact tests were carried out to assess the mechanical properties of the composites considering different fabrication conditions, such as the different degassing pressure before infusion and three different infusion vacuum pressures. The work reports a methodology to infuse ELIUM resin at a relatively high vacuum pressure of 0.8 bar. X-ray microtomography analysis showed that the produced laminates are free of defects, differently from what was reported in the literature, where void problems related to a vacuum infusion pressure higher than 0.3-0.5 bar were pointed out. Vacuum pressure values influence the mechanical characteristics of the laminate: when higher vacuum pressures are adopted, the mechanical properties of the GFRP laminates are enhanced and higher values of elastic modulus and strength are obtained. On the other hand, degassing the resin before infusion does not influence the mechanical properties of the laminates. A maximum bending and tensile strength of 420 and 305 MPa were reached by using the vacuum infusion of 0.8 bar with an elastic modulus of 18.5 and 20.6 GPa, respectively. The density of the produced laminates increases at higher vacuum infusion pressure up to a maximum value of 1.81 g/cm3 with the fibre volume fraction of each laminate.

Strong effect of liquid Fe–S on elastic wave velocity of olivine aggregate: Implication for the low velocity anomaly at the base of the lunar mantle

The origin of the seismic low velocity zone (LVZ) observed at the base of the lunar mantle is important for understanding the nature of the lunar mantle. Liquid Fe–S is considered as a possible candidate of the cause of the LVZ. However, effect of liquid Fe–S on elastic wave velocity of mantle rock has been considered to be minor, according to theoretical estimation based on the high dihedral angle of liquid Fe–S in olivine aggregate observed in previous microstructural analysis of polished sample cross sections. Here we carry out direct measurements of elastic wave velocities of liquid Fe–S-bearing olivine aggregate and report strong reduction of the elastic wave velocities in the presence of liquid Fe–S. The effects of liquid Fe–S in olivine aggregates are much more pronounced than the theoretical estimation. Three-dimensional X-ray microtomography analysis reveals that the geometry of liquid Fe–S strongly depends on the size, with larger liquid Fe–S blobs having low aspect ratios, which may predominantly affect elastic wave velocity. Since smaller spherical Fe–S blobs are much more abundant than the larger elongated blobs, conventional dihedral angle analyses based on scanning electron microscope images tend to statistically over-sample smaller blobs and under-sample larger blobs. Our results suggest that the LVZ at the base of the lunar mantle can be explained by the presence of 4.3–5.0 vol.% liquid Fe–S. The LVZ may be a hidden reservoir of highly siderophile elements (HSEs), which may explain the low abundance of HSEs in the lunar mantle compared to the Earth.

X-ray microtomography analysis of the damage mechanisms in 3D circular braided carbon fiber/epoxy resin composite tubes under axial impact compression

The dynamic behavior of three-dimensional (3D) circular braided composite tubes with different braided parameters was experimentally investigated subjected to axial impact compression using a Split Hopkinson Pressure Bar (SHPB). The damage characterization of the post-impacted tubes was examined using scanning electron microscope (SEM) and X-ray micro-computed tomography (micro-CT). The influence of braided parameters and strain rate, including braided angle, the number of braided layer and axial yarn, on the dynamic mechanical properties, progressive crush characteristics and failure mechanism of 3D braided composite tubes was analyzed in detail. It was found that the smaller braided angle and the larger numbers of braided layers contributed to better axial dynamic properties. The compressive strength, stiffness and specific energy absorption (SEA) of 3D five direction (3D5D) tubes with axial yarn were larger than those of 3D four direction (3D4D) tubes without axial yarn. Meanwhile, the dynamic mechanical response and damage patterns of braided tubes exhibited significant strain rate effects. The impact compression failure mechanisms of braided tubes were mainly fiber tows crushing, fiber breakage, fiber buckling, shear fracture, resin cracking, interfacial cracks, fiber-matrix debonding, etc.

High rate, high temperature, dendrite free plating/stripping of Li in 3-dimensional honeycomb boron carbon nitride to realize an ultrastable lithium metal anode

Lithium (Li) metal could be the anode of choice for energy dense Li-batteries owing to its high theoretical specific capacity. However, low coulombic efficiency and poor safety on account of the occurrence of the Li-dendrites during charging-discharging pose a bottleneck for practical applications. In this work, we report a high-rate plating and stripping of Li through host engineering to realize ultrastable Li metal anode (LMA). Benchmark plating/stripping efficiency could be achieved via uniquely structured, highly ordered honeycomb boron carbon nitride (HBCN) as a functional scaffold. Boron and nitrogen doping, large surface area and ordered mesoporous structure induce homogeneous solid electrolyte interface (SEI) layer formation and provide numerous nucleation sites with subsequent dendrite-free growth with 99.98 % coulombic efficiency at 8 mA cm−2 high current and 10 mAh cm−2 capacity over 3000 cycles. Via post-cycling advanced characterizations techniques of Ex-situ XPS, 3D X-ray micro-tomography analyses and FESEM, we demonstrate the formation of a stable SEI layer and morphological changes that occurred during Li plating cycles in the HBCN structure. Computational studies validate the high lithium plating-stripping efficacy of HBCN to its highly ordered porous nature, exothermic Li-binding and upshift in the Fermi levels. When tested at elevated temperature (50 °C), a stable Li plating-stripping in HBCN is realised at 4 mA cm−2 current and 10 mAh cm−2 capacity values with ∼100 % C.E.Furthermore, we report the results of testing a Li metal cell comprised of Li deposited HBCN anode and LiFePO4 (LFP) cathode.

Designing Solvated Double-Layer Polymer Electrolytes with Molecular Interactions Mediated Stable Interfaces for Sodium Ion Batteries.

Unstable cathode-electrolyte and/or anode-electrolyte interface in polymer-based sodium-ion batteries (SIBs) will deteriorate their cycle performance. Herein, a unique solvated double-layer quasi-solid polymer electrolyte (SDL-QSPE) with high Na+ ion conductivity is designed to simultaneously improve stability on both cathode and anode sides. Different functional fillers are solvated with plasticizers to improve Na+ conductivity and thermal stability. The SDL-QSPE is laminated by cathode- and anode-facing polymer electrolyte to meet the independent interfacial requirements of the two electrodes. The interfacial evolution is elucidated by theoretical calculations and 3D X-ray microtomography analysis. The Na0.67 Mn2/3 Ni1/3 O2 |SDL-QSPE|Na batteries exhibit 80.4 mAh g-1 after 400 cycles at 1 C with the Coulombic efficiency close to 100 %, which significantly outperforms those batteries using the monolayer-structured QSPE.

Milk protein-based cryogel monoliths as novel encapsulants of probiotic bacteria. Part I: Microstructural, physicochemical, and mechanical characterisation

The implementation of cryogels as alternative xero-carriers for embedding labile bioactive compounds including probiotic living cells is becoming more popular. In the present work, milk protein-based cryogels were developed by freeze-drying of indirectly acidified protein gels (10% wt. in sodium caseinate or whey protein isolate blended at varying mass ratios i.e., 1:0, 3:1, 1:1, 1:3 and 0:1) comprising Lacticaseibacillus rhamnosus GG (LGG) living cells, trehalose (5% wt.), glucose (1% wt.) and glycerol (2.5% wt.). The physicochemical, microstructural, and mechanical characteristics of the cryogels conveying LGG were measured. The acid gel contraction during the fermentation notably influenced the macroscopic (volume contraction) and microscopic aspects (porosity, thickness, and uniformity of the wall material construct) of the cryogels. The amount of monolayer water content (11.5−14.0 g.100 g−1), and total surface area (403−488 m2 g−1) as well as the glass transition temperature (Tg = 33−46 °C), of the cryogels increased proportionally to the whey protein content. X-ray microtomography analysis revealed that the mixed protein cryogels were characterised by lower porosities than their individual protein exemplars. However, the uniformity and the structure conformation of the protein network constructs were altered according to the milk protein composition of the cryogels. All the cryogels exhibited a brittle and plastic behaviour when subjected to indentation forces, with the hardest and stiffest cryogels exerting the lowest water reconstituting capacity. The microstructural assessment of the wall material at nanoscale level evidenced a satisfactory intrenching of the LGG cells, which substantiates the feasibility of the cryogels as novel probiotic xero-scaffolds.

A comparative study in 3D of bed particle layer characteristics in quartz and K-feldspar from fluidized bed combustion of woody biomass using X-ray microtomography

Bed particle layer and crack layer characteristics at different ages were studied for quartz and K-feldspar bed particles from a 30 MWth bubbling fluidized bed and a 90 MWth circulating fluidized bed, both using woody biomass as fuel. X-ray microtomography (XMT) was utilized to determine the bed particle layer distribution on the bed particles' surface. For each bed particle type, the average bed particle layer thickness as well as average volume fractions of the bed particle layer and crack layers to the entire bed particle volume were determined at three different bed particle ages by utilizing XMT analysis. Comparison of the two different bed particle types showed that K-feldspar retains a thinner bed particle layer in both conversion processes compared to quartz. Crack layers were observed extensively in quartz bed particles to the extent of 19.3 vol% and 32.1 vol% after 13 days in the BFB and the CFB, respectively, which could cause deposition of the bed particle fragments. On the contrary, K-feldspar has almost no tendency toward forming crack layers.

Analysis of the Sabellaria spinulosa Bioconstruction Growth in a Laboratory

Sabellaria spinulosa (Leukhart, 1849) is a suspension feeding polychaeta that lives in tubes consisting of terrigenous particles captured by the worm itself. They form impressive reefs containing millions of worm tubes. In temperate marine areas, under optimal environmental conditions, these structures can become natural breakwaters and can play an active role in sandy beaches’ defense. In this work, we report procedures aimed to analyze the growth of S. spinulosa bioconstructions in laboratory. By collecting biological replicas from a wild reef, this study aimed to identify sedimentological characteristics of sands that induce faster tube growth. During the tank experiments, the grain size and mineralogy of the sand were modified. By employing thin sections and X-ray microtomography analyses, the structures observed and measured during and after the tests were analogous to those naturally formed. The fastest growth was recorded in the presence of bioclastic sands with a grain size between 125 and 350 μm. Defining the physical conditions that induce faster growth is fundamental for the defense of these vulnerable habitats but also the surrounding marine environment. This study also lays the foundations for coastal protection interventions in which bioconstructions grown in the tank could be directly implanted on submerged natural and artificial substrates that are already present in situ.

Product development and X-Ray microtomography of a traditional white pan bread from plasma functionalized flour

Cold plasma (CP) technology has emerged as a novel non-thermal technology with the potential to improve food quality or impart functionality to ingredients. Our previous studies on wheat flour demonstrated how the structure and functionality of wheat flour might be modified using CP to provide an alternative to chemical additives (Chaple et al., 2020). However, understanding of the further effects of plasma functionalized ingredients in existing or new product formulation is limited. This study investigated the effects of CP treatment of wheat flour on traditional white pan bread development. The bread was formulated using plasma functionalized flour (PFF), and critical product characteristic responses were analyzed. Plasma treatment of flour positively affected the bread's expansion ratio, crust color, and water activity. Farinograph analysis suggests improvement in water absorption capacity, dough development time, and dough stability. X-Ray Microtomography (XRMT) analysis was conducted to understand how plasma functionalising the flour impacted the microstructure of bread. The 3D scans suggested no macro-change in the bread matrix compared to control; however, the porosity decreased in line with the increasing plasma treatment duration of the flour. The texture profile analysis showed an improvement in the gluten network developed in the dough developed from PFF. Sensory analysis results showed overall acceptance for bread formulated with PFF compared with a commercial sample. Overall, CP treatment of the flour improved the functionality in relation to dough and bread preparation and can thus provide an alternative to chemical additives in bread making. The CP processes may be modulated to deliver tailored effects for bread product development.

The puzzling influence of Ophiomorpha (trace fossil) on reservoir porosity: X-ray microtomography analysis

Bioturbation can influence petrophysical properties (e.g., porosity, permeability) of sedimentary rocks and, in consequence, reservoir quality. The impact can be positive, negative, or neutral, requiring detailed ichnological analysis. Ophiomorpha, a branched cylindrical burrow with diagnostic peloidal wall, may be present in bioturbated reservoirs that exhibit properties of both super-permeability and reduced porosity/permeability. However, no mechanistic understanding of how Ophiomorpha positively or negatively impacts petrophysical properties has yet been established. This study presents high-resolution X-ray microtomographic analysis of how the features of Ophiomorpha (i.e., peloidal wall vs. burrow fill) influence porosity distribution in deep-water deposits (Neogene Tabernas Basin, SE Spain). The results show that the peloidal burrow wall exhibits the lowest porosity (up to six orders of magnitude lower than burrow fill or host sediment), while surrounding sediment shows variable values. Abrupt porosity changes within the fill material likely relate to burrow-associated diagenesis. A refined understanding of the features of Ophiomorpha and their associated porosity distribution help to constrain understanding of their diverse impacts on reservoir properties.

X-ray microtomography analysis of urban soils of the Rostov region

Urban soils are exposed to transformations of physical properties which are not captured by the conventional approaches due to the presence of impurities that can distort the obtained data. Advanced visualization techniques such as X-ray computed tomography (CT) offer new opportunities of exploring heterogeneity of soil properties at horizon or aggregate scales. The studies of the structure and pore space of different types of urban soils formed on chernozems were carried out using a SkyScan 1172G tomograph. The tomographic study was carried out in the humus-accumulative horizons for six main types of urban soils. The volumetric parameters for the pore space were calculated, and pores orientation and shape parameters were calculated in 2D sections. The closed pore value was obtained as the most informative diagnostic indicator of the urban soils structural condition. A morphometric analysis of the shape and orientation of fine soil macropores with a diameter of 0.3–2.0 mm also showed significant structural differences between natural soils under woody or grassy vegetation and urban anthropogenically transformed soils. All studied soils at the aggregate scales slightly differ from each other in the value of the internal aggregate tomographic porosity. This shows that the compaction because of anthropogenic transformation occurs due to the interaggregate pore space. At the aggregate porous spaces, no changes can be traced.

Three-dimensional (3D) morphological and liquid absorption assessment of sustainable biofoams absorbents using X-ray microtomography analysis

The three-dimensional (3D) microstructure of sustainable and biodegradable protein foam absorbents is correlated to their liquid absorption characteristics using X-ray microtomography. The physicochemical relationships between the protein material pore size and liquid penetration and distribution allow for understanding how the pores' interconnectivity impacts the absorption, particularly considering capillary-driven transport phenomena within the thin nano cell walls. The foams were made via lyophilization of protein solutions containing cellulose nanofibers to emphasize the impact of the processing on the foam microstructure. The results show gaseous and solid phases of the foams covering ca. 1000 pores, providing information that cannot be obtained using traditional 2D analysis (SEM). A correlation with the channel tortuosity was established based on the statistical accuracy of the diameter and number of pores per mm3. The relationship between absorption kinetics and physical parameters enables the designing of biofoams with functionality also resembling commercial synthetic products that currently generate a high amount of nondegradable waste in our society.

The Influence of Intralayer Porosity and Phase Transition on Corrosion Fatigue of Additively Manufactured 316L Stainless Steel Obtained by Direct Energy Deposition Process.

A direct energy deposition (DED) process using wires is considered an additive manufacturing technology that can produce large components at an affordable cost. However, the high deposition rate of the DED process is usually accompanied by poor surface quality and inherent printing defects. These imperfections can have a detrimental effect on fatigue endurance and corrosion fatigue resistance. The aim of this study was to evaluate the critical effect of phase transition and printing defects on the corrosion fatigue behavior of 316L stainless steel produced by a wire laser additive manufacturing (WLAM) process. For comparison, a standard AISI 316L stainless steel with a regular austenitic microstructure was studied as a counterpart alloy. The structural assessment of printing defects was performed using a three-dimensional non-destructive method in the form of X-ray microtomography (CT) analysis. The microstructure was evaluated by optical and scanning electron microscopy, while general electrochemical characteristics and corrosion performance were assessed by cyclic potentiodynamic polarization (CCP) analysis and immersion tests. The fatigue endurance in air and in a simulated corrosive environment was examined using a rotating fatigue setup. The obtained results clearly demonstrate the inferior corrosion fatigue endurance of the 316L alloy produced by the WLAM process compared to its AISI counterpart alloy. This was mainly related to the drawbacks of WLAM alloys in terms of having a duplex microstructure (austenitic matrix and secondary delta-ferrite phase), reduced passivity, and a significantly increased amount of intralayer porosity that acts as a stress intensifier of fatigue cracking.

Reducing Impedance at a Li-Metal Anode/Garnet-Type Electrolyte Interface Implementing Chemically Resolvable In Layers.

Garnet-type Li7La3Zr2O12 (LLZO) is a potential electrolyte material for all-solid-state Li-ion batteries mainly because of its reported excellent chemical stability in contact with Li metal. But good wettability of LLZO and 100% surface coverage of lithium are still a challenge. This study elucidated the suitability of magnetron-sputtered indium in Li(In)/LLZO/Li(In) symmetrical model cells as one of the promising interfacial modifications reported in the literature. Importance was given to the impact of preparation parameters on the surface coverage of Li(In)/LLZO interfaces and the consequences of impedance, cycling stability, and critical current density. SEM and EDXS analyses of In layers of thickness 100 nm to 1 μm revealed complete dissolution of indium in the lithium anode after annealing; 300 nm In layers annealed at 220 °C/10 h provided a surface coverage of >80%, best reproducibility, and a supreme interface resistance Rint of 12.4 Ω·cm2. Presuming a surface coverage of 100%, an ultimate interface resistance close to 1 Ω·cm2 can be expected. The critical current density was determined as 200-500 μA/cm2 at a charge of 100-250 μAh, whereas 500 μA/cm2 and above affected cell stability. The increasing voltage plateau was assigned to the increase of the interface resistance Rint and the electrolyte resistance RG+GB. SEM, EDXS, and X-ray microtomography analyses after voltage breakdown confirmed Li-dendrite growth along grain boundaries into LLZO, often curved parallel to the interface, indicating short-circuiting of the solid electrolyte. Grain boundary characteristics are supposed to be decisive for lithium deposition in and failure of garnet-type solid electrolytes after cycling.

Synchrotron X-ray micro-tomography investigation of the early hydration of blended cements: A case study on CaCl2-accelerated slag-based blended cements

In situ X-ray Micro-Tomography (XMT) analyses with a pixel size of 0.325 µm were conducted on slag-based blended cements containing 75% of Ground-Granulated Blast-Furnace Slags (GGBS) and 25% of Ordinary Portland Cement (OPC), with or without CaCl2 acceleration. Results show the identification of the main cementitious phases and the need to perform data repeatability tests in order to allow their quantification. Investigation of the early hydration during the first 31 h of hydration by image subtraction showed (i) the dissolution of OPC/GGBS, (ii) the precipitation of hydrates including C-S-H, (iii) the accelerating effect of CaCl2, and (iv) phase-identification based on their specific grey level.

X-ray microtomography analysis of gaps and voids in the restoration of non-carious cervical lesions with different composite resins.

Resin composites are the most widely used material for restoring cervical defects. However, the high failure rate of these restorations is still a concern. The aim of this in vitro study was to evaluate, using microtomography (μCT), the interfacial gap and voids formation in Class V cavities in premolars restored with materials with lower polymerization shrinkage combined with different restorative techniques. Cervical defects were created in 30 intact premolar and were randomly distributed to be restored by one of the following techniques (n = 6): Composite resin with two increments (CR), organic modified polymer (ORMOCER) with single (OR1) or two increments (OR2, or low viscosity bulk-fill composite resin with single (BF1) or two increments (BF2). Each tooth was scanned before filling to determine the volume of interest (VOI) to be applied in the second μCT after restoration and to control the cavity volume among the groups. In the μCT after filling, the volume of interfacial gaps and voids was calculated for each group. The groups were compared using one-way and Tukey HSD post hoc test (α = 0.05). It was possible to identify higher gap formation in the OR1 group and higher void formation in CR group (P < 0.05). OR2 group showed better results than the group with one increment. BF2 showed the best filling capacity. It was possible to conclude that the material and the number of increments directly influenced the internal adaptation and voids formation of Class V restorations.

X-ray microtomography analysis to approach bioturbation's influence on minor-scale porosity distribution: A novel approach in contourite deposits

Micro-CT analysis is employed for the first time to evaluate the effects of bioturbation on porosity distribution in contourite facies, namely: i) sandy clastic contourites from the Late Miocene Moroccan Rifian Corridor; and ii) dominant-calcareous contourites from Eocene- Middle Miocene Cyprus paleoslope. Porosity distribution is affected by bioturbation due to trace maker behavior and burrow infilling, but there is no clear, single relationship. Macaronichnus, especially M. segregatis, located in sandy clastic contourite facies would have the greatest impact, increasing porosity due to the grain-selective deposit-feeding behavior of the trace maker. Porosity values are up to three times higher in the burrow rim than in the infilling material, which favors a dual-porosity flow medium. Samples with M. s. degiberti record higher porosity values in the host sediment than in the burrow fill, but any increase of porosity in the burrow rim is not certain. This variable influence on porosity distribution (M. segregatis vs. M. s. degiberti) might be associated with different trace maker behaviors during feeding activities, or even with variable producers. Chondrites located in muddy chalk contourite facies has a neutral effect on porosity distribution, porosity data of the host sediment and the filling material being similar, in agreement with a comparable grain size. Thalassinoides located inside calcarenitic contourite facies has a minor effect on porosity distribution, showing similarities between passively infilled material and the host sediment. Our results also reveal the importance of secondary diagenetic overprints when homogenizing primary differences. Accordingly, understanding the impact of bioturbation on porosity distribution in contourite facies appears to be a key factor for evaluating the real potential of these unconventional reservoirs. This study represents a first step forward in discerning the relationship between contourite facies, ichnological features, petrophysical properties and reservoir geology.