Pore Shape Research Articles

Bone Regeneration Induced by Patient-Adapted Mg Alloy-Based Scaffolds for Bone Defects: Present and Future Perspectives.

Treatment of bone defects resulting after tumor surgeries, accidents, or non-unions is an actual problem linked to morbidity and the necessity of a second surgery and often requires a critical healthcare cost. Although the surgical technique has changed in a modern way, the treatment outcome is still influenced by patient age, localization of the bone defect, associated comorbidities, the surgeon approach, and systemic disorders. Three-dimensional magnesium-based scaffolds are considered an important step because they can have precise bone defect geometry, high porosity grade, anatomical pore shape, and mechanical properties close to the human bone. In addition, magnesium has been proven in in vitro and in vivo studies to influence bone regeneration and new blood vessel formation positively. In this review paper, we describe the magnesium alloy's effect on bone regenerative processes, starting with a short description of magnesium's role in the bone healing process, host immune response modulation, and finishing with the primary biological mechanism of magnesium ions in angiogenesis and osteogenesis by presenting a detailed analysis based on a literature review. A strategy that must be followed when a patient-adapted scaffold dedicated to bone tissue engineering is proposed and the main fabrication technologies are combined, in some cases with artificial intelligence for Mg alloy scaffolds, are presented with examples. We emphasized the microstructure, mechanical properties, corrosion behavior, and biocompatibility of each study and made a basis for the researchers who want to start to apply the regenerative potential of magnesium-based scaffolds in clinical practice. Challenges, future directions, and special potential clinical applications such as osteosarcoma and persistent infection treatment are present at the end of our review paper.

Characterization and Microstructure of Recycled Eroded Particles from Die-Sink Electro Discharge Machining of H11 Alloy for Applicability in Additive Manufacturing

Different waste streams from electro discharge machining (EDM) were investigated for an upcycled usage in processes for additive manufacturing (AM). These erosion sludges accumulate in filter cartridges and at the bottom of machining basins. The enclosed particles were extracted, sieved and investigated via laser diffraction, dynamic image analysis, scanning electron microscopy, optical emission spectroscopy, elemental analysis and flowability measurements. Additionally, thermal, crystallographic and metallographic investigations as well as X-ray micro-computed tomography (µ-CT) were utilized for the characterization of particle and material properties. In general, eroded powders fulfill the requirements for AM regarding particle size and shape very well, which is confirmed in morphological investigations and powder flow characteristics showing similar properties as the H11 AM reference material. The chemical composition of the powders is equal to the machined H11 alloy, except for the high carbon content. Carbon is entrapped in the iron lattice originating from pyrolysis of the present dielectric fluid and the graphite electrode during rapid solidification, which leads to a transition from martensite to cementite structures. This change is observed in the microstructure of powders, in which acicular primary cementite and austenite are present. After remelting with slow heating and cooling rates the microstructure changed to ledeburite II with retained austenite and martensitic phases. The pore size and shape distributions obtained by µ-CT measurements showed a pore formation in the compact sample. These results provide a fundament of major properties as well as handling and recycling suggestions for eroded particles enclosed in waste sludges.Graphical

Preparation of Cellulose Pineapple (Ananas comosus) Peel as Adsorbent of Remazol Yellow Dye

The extraction of cellulose from pineapple (Ananas comosus) peel has been carried out through delignification using alkaline and hydrolysis with acid. The extraction of cellulose was carried out by de-waxing, delignification followed by hydrolysis with H2SO4 acid. The cellulose obtain was identified by FTIR and SEM-EDS. The results showed that the FTIR spectra of pineapple peel cellulose contain hydroxyl and carboxyl functional groups which useful in the adsorption process. The morphology of cellulose has a more homogeneous and porous shape. The cellulose obtained was used for adsorption of Remazol yellow dye by studying adsorption parameters, namely the effect of pH, contact time and solution concentration. The adsorption process was obtained at pH 2, the optimum contact time was 30 minutes and concentration at 100 mg/L with an adsorption capacity is 19.888 mg/g.

Porosity effect on the functional properties and energy harvesting performance of Ba0.85Ca0.15Ti0.90Zr0.10O3 ceramics

AbstractIn this study, the effect of porosity on the structural and functional (dielectric, ferroelectric, nonlinear, and piezoelectric) properties in Ba0.85Ca0.15Ti0.90Zr0.10O3 ceramics was investigated. Various levels of microporosity in the range of 3% to 31 vol.% have been produced using poly(methyl methacrylate) microspheres as sacrificial templates. The structural investigation indicates a phase coexistence, as expected for this composition at room temperature. The maximum permittivity decreases with increasing porosity, from around 7000 (ceramic with 3 vol.% porosity) down to 3500 (ceramic with 31 vol.% porosity), and the Curie temperature shifts from 47 to 67°C when increasing porosity, related to the possible porosity‐induced structural and internal stress modifications. An enhanced piezoelectric response was found in the Ba0.85Ca0.15Ti0.90Zr0.10O3 ceramic with intermediate porosity around 18 vol.%, with the highest value of piezoelectric response of 470 pC/N and a figure of merit of 7.3 pm2/N. The optimum piezoelectric properties at the intermediate porosity level are related to the microstructural changes (pore shape and connectivity) and possible field‐induced structural modifications. The piezoelectric energy harvesting measurement results have shown the possibility of using Pb‐free porous ferroelectric materials in devices for energy harvesting applications.

Experimental and Numerical Simulations of Pore Structures and Seepage Characteristics of Deep Sandstones

Previously conducted studies have established that deep underground rock masses have complex pore structures and face complex geological conditions. Therefore, the seepage problem of such rock masses seriously affects engineering safety. To better explore the seepage law of deep rock masses and ensure engineering safety, indoor experimental methods such as casting thin sections, scanning electron microscopy, and mercury intrusion testing were utilized in this study. The microscopic pore shape, size, distribution, and other structural characteristics of sandstone in coal bearing strata were analyzed. The tortuosity calculation formula was obtained by the theoretical derivation method. And a numerical model was established for seepage numerical simulation research through microscopic digital image methods. The seepage law of surrounding rocks in the Tangkou Coal Mine roadway under different conditions is discussed. The research results indicate that the complexity of the pore structure in porous media leads to an uneven distribution of flow velocity and pressure within the medium. Meanwhile, with the change of physical properties, the fluid flow characteristics also undergo significant changes. The research results can effectively guide micropore water blocking, reduce the impact of groundwater on the environment, ensure the environment and safety of the project, and provide guidance for other geological projects.

Frequency-dependent velocities and attenuations in fluid-saturated rocks: Fractures aligned in isotropic medium with random pore shape

The modeling of seismic wave velocity and attenuation is crucial for the interpretation of seismic data. In fluid-saturated rocks, the presence of fractures causes dispersion and attenuation of seismic waves due to fluid flow between cracks and pores. Meanwhile, the parallel distribution of cracks is an important reason for the anisotropy of rocks. Combined with poroelasticity theory, we extend Chapman’s model to media with penny-shaped fractures and an isotropic porous matrix, for which no restrictions are placed on the pore shape of the matrix. We conduct simulations at different frequencies to indicate the predicted anisotropy of velocity and attenuation. The variation of velocities and attenuations with orientation angle is consistent with Chapman’s model. Because a typical porous matrix is used in the new model, predicted velocities are lower than those under assumption of spherical matrix pores. Then, we analyze the effect of pore compressibility of the matrix on the velocity and attenuation. We also conduct discussions about the effect of different porosities on velocity and attenuation. The analysis indicates that the predictions of the new model are more closely related to the modulus of the porous matrix than Chapman’s model. The strength of fluid flow in the new model also will change with the matrix pores. The comparison of the new model and Chapman’s model with experimental data indicates that the new model is in better agreement with the experimental results.

A bimanual comparison of variation in sweat pores with sex and age: a brief dermatoglyphic survey of population in Delhi-NCR

BackgroundPersonal identification using partial fingerprints poses a major challenge in forensic investigations. In light of such restrictions, sweat pore characteristics have shown to be a possible alternative. However, limited research has been done on these due to their minute size. The present study was undertaken with the objective of studying the differences in pore frequency, pore shapes (circular and non-circular), and pore positions (middle and periphery) with respect to sex, bimanual, and age in the population of Delhi-NCR (National Capital Region). As there is no universal approach for defining the evaluation area of pore analysis, we used fingerprint patterns to demarcate a 9mm2 area of analysis. The rolled-inked fingerprints of 200 individuals (100 males and 100 females) belonging to 18-60 years of age were examined using microscopy.ResultsThe obtained data for all prints was analysed and compared with respect to the different variables. The results showed statistically significant bimanual variations for both sexes. In females, all studied pore characteristics except the number of pores at the middle position were significantly higher in the right hand as compared to the left hand. In males, only the number of pores at the peripheral position was significantly higher in the right hand as compared to the left hand. However, no significant differences were observed in pore characteristics between the two sexes and among the different age groups. Moreover, several pore characteristics showed a significant correlation with age in males as compared to females where no significant correlations were observed.ConclusionsSignificant bimanual variations highlighted the potential application of pore characteristics for forensic practice; wherein a fingerprint examiner might determine the probable hand used for the commission of the crime, thereby strengthening the evidentiary value of partial fingerprints. These findings also suggest that the sex and age of an individual cannot be determined by pore characteristics.

Preparation of NiAl-AlMg6 Functionally Graded Composite Using the Energy of a Highly Exothermic Ti-C Mixture during Self-Propagating High-Temperature Synthesis.

A functionally graded composite NiAl-AlMg6 was prepared using the pressure of gaseous reaction products (impurity gases) produced during the synthesis of reactive powders in a sealed reactor. It has been shown that this method can be used to prepare a NiAl/AlMg6 composite with both chaotically oriented pores in the NiAl layer and unidirectionally oriented pores (lotus-type pores). The pore shape in NiAl was found to be dependent on the pressure of the impurity gases and hydrogen present in the starting titanium powder. A mechanism for pore formation in NiAl and AlMg6 composite during SHS is proposed. Thus, functionally graded high-temperature composites can be produced by SHS in a sealed reactor using the chemical reaction energy and the pressure of impurity gases and hydrogen. Additionally, minimizing the influence of impurity gases on the contact zone increases the interface area between NiAl and AlMg6.

Structural Chemistry of Zeolitic Imidazolate Frameworks.

Zeolitic imidazolate frameworks (ZIFs) are a subclass of reticular structures based on tetrahedral four-connected networks of zeolites and minerals. They are composed of transition-metal ions and imidazolate-type linkers, and their pore size and shape, surface area, and functionality can be precisely controlled. Despite their potential, two questions remain unanswered: how to synthesize more diverse ZIF structures and how ZIFs differentiate from other crystalline solids. In other words, how can we use our understanding of their unique structures to better design and synthesize ZIFs? In this Review, we first summarize the methods for synthesizing a wide range of ZIFs. We then review the crystal structure of ZIFs and describe the relationship between their structure and properties using an in-depth analysis. We also discuss several important and intrinsic features that make ZIFs stand out from MOFs and discrete molecular cages. Finally, we outline the future direction for this class of porous crystals.

Microstructural Characterization of PCL-HA Bone Scaffolds Based on Nonsolvent-Induced Phase Separation.

Composite materials containing pores play a crucial role in the field of bone tissue engineering. The nonsolvent-induced phase separation (NIPS) technique, commonly used for manufacturing membranes, has proven to be an effective method for fabricating composite scaffolds with tunable porosity. To explore this potential, we produced 10% (w/v) poly(caprolactone) (PCL)-nanohydroxyapatite (HA) composite porous film scaffolds with varying HA contents (0/10/15/20 wt %) and two thicknesses (corresponding to 1 and 2 mL of solution resulting in 800-900 and 1600-1800 μm thickness, respectively) using the NIPS method. We conducted a comprehensive analysis of how the internal microstructure and surface characteristics of these scaffolds varied based on their composition and thickness. In particular, for each scaffold, we analyzed overall porosity, pore size distribution, pore shape, and degree of anisotropy as well as mechanical behaviors. Micro-CT and SEM analyses revealed that PCL-HA scaffolds with various HA contents possessed micro (<100 μm) scale porosity due to the NIPS method. Greater thicknesses typically resulted in larger average pore sizes and greater overall porosity. However, unlike in thinner scaffolds, greater/higher HA content did not exhibit a direct correlation with a greater pore size for thicker scaffolds. In thinner scaffolds, adding HA above an effective threshold content of 15 wt % and beyond did lead to a greater pore size. The higher pore anisotropy was in line with the higher HA content for both groups. SEM images demonstrated that both groups showed highly uniformly distributed internal microporous morphology regardless of HA content and thickness. The results suggest that NIPS-based scaffolds hold promise for bone tissue engineering but that the optimal HA content and thickness should be carefully considered based on desired porosity and application.

Leveraging Surface Chemistry and Pore Shape Engineering in a Metal‐Organic Framework for One‐Step Olefin Purification

AbstractPurifying olefin from ternary paraffin/olefin/alkyne mixtures through a one‐step adsorption process is extremely desirable. Herein, a stable zirconium(IV) metal‐organic framework with a customized pore surface composed of nonpolar phenyl and slightly polar thiophene rings is reported to access the adsorption preference of paraffin and alkyne over olefin. Noteworthily, this material displays a superior ability to discriminate C3 hydrocarbon molecules, which is principally more challenging compared with C2 ones and rarely documented. Computational studies disclose that its featured pore shape fits well with C3 gas molecules, enabling them to get close contact with the immobilized affinity sites. Leveraging surface chemistry and pore shape engineering synergistically gives rise to excellent C3 adsorption capacities (&gt;5 mmol g−1) and concurrently high C3H8/C3H6 (1.4) and C3H4/C3H6 (1.9) selectivities (at 298 K and 1 atm). Dynamic column breakthrough experiments demonstrate that one‐step purification of C2H4 and C3H6 can be simultaneously realized on this material.

Structural design of gradient porous dental implant based on orthogonal test.

To solve the current problems of loosening and dislodging caused by the high elastic modulus of solid implants, we attempted to study a gradient porous dental implant that can lower the stress concentration and reduce the elastic modulus. SolidWorks software was utilized to design the abutment and mechanical structure of the gradient porous implant. The mechanical properties of the gradient porous implant were evaluated by an orthogonal experimental design from four aspects: pore shape, pore diameter, porous layer height, and circumferential distribution. ANSYS software was used to evaluate the distribution of Von-Mises stress in the implant and its surrounding bone tissues under different structural combination parameters to derive the optimal combination of gradient porous implant parameters. The effects of the four factors, namely, pore shape, pore diameter, porous layer height and pore distribution, on the maximum Von-Mises stress on the implant were as follows. As the pore shape became smaller and the circumferential distribution decreased, the Von-Mises stress decreased significantly. The pore diameter went from 500 μm to 600 μm and then to 700 μm. The Von-Mises stress decreased and then increased. It increased with the increase in the height of the porous layer. The final optimal combination of parameters for the gradient porous implant was as follows: square pore shape, pore diameter of 600 μm, porous layer height of 3 mm, and quadratic step in pore distribution.

Characterization of 3D-printed graphene-reinforced PLA scaffold for bone regeneration

In orthopedic application, bone tissue engineering (BTE) is a novel treatment method for bone defects involving bone regeneration using an artificial supporting structure called scaffold. The aim of this work is to fabricate graphene-reinforced poly(lactic acid) (PLA/Gr) scaffolds with different pore shapes (circular, square and hexagonal) and different pore sizes (1000, 1500 and 2000 μm) using the fused deposition modeling process. The characteristics of the three-dimensionally (3D) printed PLA/Gr scaffolds were analyzed through Fourier transform infrared spectroscopy, thermogravimetric analysis, derivative thermogravimetry, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The water contact angle measurement showed a hydrophilic surface (70 ± 2.7°) for scaffolds with a pore size of 1000 μm. Mechanical property studies showed that the scaffold with circular 1000 μm pores had a compressive strength of 18.53 ± 0.90 MPa, which was similar to the cancellous bone value. In addition, this study involved an examination of the in vitro bioactivity, water uptake and biodegradation characteristics of the scaffolds. The results reveal that the 3D-printed PLA/Gr scaffold featuring a circular pore shape with a pore size of 1000 μm exhibits great potential as an implant for BTE.

The effect of nodal connectivity and strut density within stochastic titanium scaffolds on osteogenesis.

Modern orthopaedic implants use lattice structures that act as 3D scaffolds to enhance bone growth into and around implants. Stochastic scaffolds are of particular interest as they mimic the architecture of trabecular bone and can combine isotropic properties and adjustable structure. The existing research mainly concentrates on controlling the mechanical and biological performance of periodic lattices by adjusting pore size and shape. Still, less is known on how we can control the performance of stochastic lattices through their design parameters: nodal connectivity, strut density and strut thickness. To elucidate this, four lattice structures were evaluated with varied strut densities and connectivity, hence different local geometry and mechanical properties: low apparent modulus, high apparent modulus, and two with near-identical modulus. Pre-osteoblast murine cells were seeded on scaffolds and cultured in vitro for 28days. Cell adhesion, proliferation and differentiation were evaluated. Additionally, the expression levels of key osteogenic biomarkers were used to assess the effect of each design parameter on the quality of newly formed tissue. The main finding was that increasing connectivity increased the rate of osteoblast maturation, tissue formation and mineralisation. In detail, doubling the connectivity, over fixed strut density, increased collagen type-I by 140%, increased osteopontin by 130% and osteocalcin by 110%. This was attributed to the increased number of acute angles formed by the numerous connected struts, which facilitated the organization of cells and accelerated the cell cycle. Overall, increasing connectivity and adjusting strut density is a novel technique to design stochastic structures which combine a broad range of biomimetic properties and rapid ossification.

Controlling C–C coupling reactivity through pore shape engineering of B-doped graphyne family

Graphyne is an interesting carbon allotrope characterized by sp-sp2 hybridized carbon bonds, which allow for structure variability. Though there are studies evaluating the electrical and mechanical properties of various structures, studies utilizing its structural variety toward catalyst applications are minor. In electrocatalytic CO2 reduction reactions (CRR), producing valuable C2+ products, such as C2H4 or C2H5OH, under mild conditions is still challenging. The bottleneck has been assigned to the carbon-carbon (C–C) coupling reaction, such as 2*CO → *OCCO. In this reaction, one requires strong binding to the catalyst to enhance neighboring CO concentration, but at the same time, one needs to have low C–C coupling barriers making the OC-CO bond. Following our previous study, which showed B-doped γ-graphyne can be a catalyst for ethanol production, we conducted theoretical investigations on a range of B-doped graphyne families using density functional theory. Out of the 15 different structures studied, four, 4,12,2-, sR-, γ-, and 6,6,12-graphynes, show promising potential for CRR. B-doped 4,12,2-graphyne, with small square and rectangular pores, had a very low C–C coupling barrier of 0.34 eV with strong 2*CO adsorption (−2.5 eV). Furthermore, our research revealed a correlation between the heat of reaction (2*CO → *OCCO) and the average pore area around the acetylenic linker reaction site. Smaller pores give a favorable orientation of two CO molecules, resulting in low reaction barriers.

Using Working Parameters to Control Formation and Shape of Lotus-Type Pores

The development and final shape of lotus-type pores can be manipulated in advance during unidirectional solidification in this study. Independent parameters considered are solidification rate, ambient pressure, and factor accounting for solute concentration at a selected reference state in liquid deviated from that at the top surface. Lotus-type porous materials have contemporarily been used in heat sinks, energy including shock, vibration, and sound absorption in aircraft engines, etc., which strongly depend on directions, distributions, and pore shapes in solid. This model accounts for transient gas pressure in the pore affected by solute transfer, gas, capillary and hydrostatic pressures, and Sieverts’ law or Henry’s law at the bubble cap and top surface. Solute transport across the cap self-consistently accounts for solute convection at the cap based on a reference concentration deviated from that at the top free surface, the amount of solute rejected by the solidification front into the pore, and the convection-affected concentration at the solidification front. The resulting simultaneous systems of unsteady first-order ordinary differential equations are solved by a MATLAB code. The length of lotus-type pores is also interpreted by the conservation of the solute content in the system. The predicted final shapes of lotus-type pores agree with algebraic results previously confirmed by available experimental data.

Experiment and finite element modelling on compressive and damage evolution of graphene nanoplatelet reinforced Porous cement composites

As reinforcing nano-fillers, graphene nanoplatelets (GNPs) have shown considerable promise for developing high-performance cement composites. However, the influence of GNP orientation and pores on the compressive and damage evolution of the GNP reinforced cement composites (GNPRCCs) remains unclear. This work employs three-dimensional finite element modeling along with experiments to provide fundamental insights into the property-microstructure relationships in the GNPRCCs. The model which incorporates GNP and pore as individual phases with cohesive interactions is developed and validated. The simulations reveal that the alignment of GNPs at 45° has the most significant effect on improving the load-bearing capacity and damage resistance of the GNPRCCs. A larger GNP diameter-to-thickness ratio is more beneficial for enhancing crack bridging and propagation control. The orientation and porosity of pores are evidenced to have significant effects on the damage behaviours of the GNPRCCs, where the pore shape shows negligible effects. These findings elucidate the underlying mechanisms that underpin the mechanical behavior of GNPRCCs, providing key guidelines to tailor and optimize the microstructural features for advanced construction materials with superior performance and durability.

Microscopic study of the impact of particle morphology on the compressibility of calcareous sands

As a kind of unique marine sediment, Calcareous sand exhibits high compressibility because its irregular particle morphology leads to the formation of large interparticle voids. In this study, using calcareous sand samples from the South China Sea, we employed X-ray CT scanning technology to reveal the microstructural evolution of calcareous sand during compression. This allowed us to establish correlations between particle morphology, relative density, vertical stress, and microstructural parameters. The research findings are as follows: (1) Samples with a higher proportion of cube shape particles have larger initial void ratios, and experience a more significant decrease in void ratio under stress. Dense samples exhibit greater deformation resistance and lower particle breakage rates, resulting in a slower reduction in void ratio under stress. (2) The number of pores in the samples follows a V-shaped trend with an increase in the proportion of cube shape particles, reaching its minimum when the proportions of cube shape and platy shape particles are balanced. The number of pores increases with an increase in vertical stress and relative density. (3) The equivalent pore diameter and pore volume of the samples exhibit an inverted V-shaped trend with an increase in cube shape particle content, reaching their maximum when the proportions of cube shape and platy shape particles are balanced. (4) The more cube shape particles in the sample, the more irregular the pore shapes become. Under vertical stress, the influence of particle morphology on pore shape gradually diminishes until it disappears. (5) The particle coordination number in the samples predominantly falls within the range of 3.79–5.68. The coordination number increases with increasing relative density and vertical stress, with vertical stress exerting a significantly greater influence on the coordination number than relative density. Under vertical stress, samples with more cube shape particles exhibit smaller coordination numbers and higher particle breakage rates.

Process Parameter Prediction in Laser Powder Bed Fusion Using an Artificial Neural Network

Pores are the inevitable concomitant in the current state of laser powder bed fusion (PBF-LB/M) of AlSI10Mg components. Various pore characteristics, such as pore size and pore shape, influence the quality and affect the intended functionality of the component. Today, the experimental effort to find the appropriate process parameters for additive manufacturing (AM) results in high costs and long time-to-market. Pore formation is highly dependent on the applied process parameters. Consequently, pores can also be seen as an individual process fingerprint. Computed tomography is a commonly used measurement tool for AM components and can be used to comprehensively investigate process-induced defects. Furthermore, X-ray data allows an accurate categorisation of pores and provides a large amount of labelled data for supervised learning applications. The applied classification method classifies the pores into six classes (A-F) according to their shape and size. A total number of 3,066,249 pores detected in cylindrical samples were categorised and used for machine learning. The purpose of this work is to demonstrate an approach for predicting AM process parameters depending on the resulting pore distribution using supervised learning methods. The result is an expandable machine learning model based on an artificial neural network.

The effect of organic matter amendments on soil surface stability in conventionally cultivated arable fields

AbstractIn this study, new and traditional organic wastes (green waste compost, farmyard manure (FYM), anaerobic digestate or straw) were ploughed into an arable field experiment at a range of rates (1–3 t C ha−1) and under spring and winter cropping rotations for 5 years. The stability of the soil surface structure (&lt;5 cm) was assessed in Years 3, 4 and 5 to guide the use of organic wastes in arable field management. Aggregate stability was determined by immersing each soil sample in water (fast‐wetting test, relevance to summer storms) and measuring the size distribution of the aggregates (mean weight diameter, MWD). The MWD value was compared with the different classes of aggregate stability (very stable, stable, medium, unstable or very unstable) to classify each result. All the arable field samples were classified as unstable, and there were no significant differences (p &gt; .05) in MWD after any treatment. Potentially, this approach is too imprecise to detect differences, so pore‐scale analyses using CT scanning were used. There were no significant differences in porosity or pore shape (features associated with microbial activity) between the control and organic waste treatments. The results contradicted published data from the Broadbalk experiment (established in 1843), which was the basis for this study, so its soils were studied to understand this discrepancy. Broadbalk soils were classified as unstable, including soils treated with annual FYM applications. Instead, we found a significant relationship between MWD and clay content and previous interpretations had not taken this variable (23%–39% clay content) texture into consideration. In conclusion, to achieve a stable soil surface structure, a 150% improvement in aggregate stability would be needed here and ploughing in organic wastes was not a successful management approach on these arable field experiments.