Consolidation Agent Research Articles

Zinc Oxide Nanoparticles in Leather Conservation: Exploring the Potential of Hydroxypropyl Cellulose/Zinc Oxide Nanocomposite as a Leather Consolidation Agent

This research presents a comprehensive study on the application of hydroxypropyl cellulose/zinc oxide nanocomposite (HPC/ZnO NC) as an effective consolidant in leather conservation. The critical focus is to prevent photooxidative degradation, a significant challenge in preserving historical leather artifacts. The nanocomposite was evaluated for its protective capabilities against environmental stressors like UV radiation and moisture, mechanical robustness, and potential to stabilize acid-damaged leather. The uniform dispersion of ZnO NPs in the HPC matrix was revealed as crucial for improving leather properties, which was confirmed through SEM imaging. The HPC/ZnO NC coating effectively prevented UV-induced microcracks, surface degradation and collagen denaturation. It also demonstrated enhanced mechanical resistance, inhibiting the reduction in leather’s maximum tolerable force and increasing the elongation index, even after aging. Additionally, it exhibited improved water-repellent properties and increased the pH of the leather, offering potential benefits for the treatment of acid-degraded leathers. Overall, the findings affirm that the application of HPC/ZnO NC significantly augments the physical and mechanical properties of leather, providing enhanced resistance to environmental degradation.

In-situ micro-CT scanning and compressive strength assessment of diammonium hydrogen phosphate (DAP) treated chalk

The occurrence of wellbore mechanical failure is a consequence of the interaction among factors such as in situ stress, rock strength, and engineering procedures. The process of hydrocarbons production, causing reduction of pore pressure, alters the effective stresses in the vicinity of a borehole, leading to borehole instability issues. Estimating the rocks’ elastic modulus and compressive strength is essential to comprehend the rock matrix’s mechanical response during drilling and production operations. This study aimed to assess the practicality of Diammonium Hydrogen Phosphate (DAP) application as a chemical for strengthening chalk in hydrocarbon reservoirs, to make it resistant to high stresses and failure during drilling and production. The mechanical and physical properties of Austin chalk rock samples treated with DAP under mimicked reservoir conditions were studied. The results showed that DAP is a highly effective carbonate rock consolidating agent that improves the mechanical strength of the chalk. Compressive test measurements conducted on rocks treated at two different temperatures (ambient and 50 °C) showed that DAP effectively strengthened the rock matrix, resulting in an increase in its compressive strength (22–24%) and elastic modulus (up to 115%) compared to the untreated sample. The favorable outcomes of this research suggest that the DAP solution holds promise as a consolidation agent in hydrocarbon reservoirs. This contributes to the advancement of knowledge regarding effective strategies for mitigating mechanical failures of the wellbore during drilling and production.

Study on leaching and curing mechanism of heavy metals in magnesium coal based backfill materials

In order to promote the resource utilization of bulk solid waste, it is an effective way to improve the comprehensive utilization level of solid waste and alleviate the environmental pressure caused by storage by using all solid waste as raw material for backfill cementing. In this paper, a magnesium coal based backfill material (MCB) with modified magnesium slag (MMS) and fly ash (FA) as cementing agents, coal gasification coarse slag (CGCS) and coal gangue (CG) as aggregates was proposed. First, the mechanical properties of MCB were studied and then the hydration effect was verified microscopically. Then, the leaching characteristics of raw materials CGCS, CG, and backfill material MCB were characterized. Furthermore, the mechanism of heavy metal leaching and solidifying of MCB was revealed by studying As and Pb. The results show that: (1) The addition of a suitable amount of CGCS with potential pozzolanic activity produces more MCB hydration products such as C-S-H and AFt with a high CG-CGCS ratio. The compressive strength reaches the maximum value of 10.21 MPa when the curing time is 28 days and the CG-CGCS ratio is 3:1. (2) The leaching levels of the target elements (As, Pb, Cr, Mn, Zn, Cu, Cd, Hg, Ag) of CG meet the limits of the class III groundwater quality standard (III-GQSL) in GB/T 14848–2017. The concentration of Pb in CGCS is 12 μg/L, which exceeds the III-GQSL limit of 10 μg/L. The overall leaching risk is CGCS>CG. (3) MCB has a good stabilization/solidification effect on the heavy metal elements Cd, As, and Pb in raw materials. The heavy metal leaching results of MCB with a low CG-CGCS ratio meet the limit of III-GQSL, and the environmental leaching risk is low. (4) In addition to physical encapsulation, the main curing mechanisms of MCB include chemical bonding, alkaline environment, and adsorption. MCB can be used as a potential consolidation agent for the solidification of heavy metal elements. While having good mechanical properties, it can also treat solid waste and effectively stabilize/solidify toxic elements in materials and has the potential for safe application in backfill.

Bohemian sandstone for restoration of cultural heritage sites: 3D microstructure and mass transport properties

We characterised the microstructure of sandstone from the Msene locality (Czech Republic) by combining X-ray computed micro-tomography, back-scattered electron imaging, chemical composition analysis and textural analysis and gas permeation. Both, 2D and 3D images were commonly processed by linking an anisotropic non-linear diffusion filter and a segmentation method based on power watershed. This approach guaranteed binarised outputs that were almost the same in wide ranges of spatial-filter and power-watershed parameters, i.e., subjective choices of the parameters played the negligible role. The rock pore structure was found to be statistically homogeneous and almost isotropic with perfectly connected pore space. We also partitioned the void and solid phases into either grains or pores and throats, which enabled us to study characteristic sizes and connectivity of partitioned regions. By comparing pore and throat sizes, we demonstrated the significant convergent-divergent nature of the pore space because the throat size covered at most one half of the total surface area per pore (cavity). In addition, we calculated coordination numbers for all pores (cavities) to verify almost perfect connectivity of internal pores with those at the external surface. Effective (macroscopic) transport properties of the reconstructed pore space were simulated and the results were validated by experimentally observing steady state flow of inert gas. These findings appear to be a favorable starting point for future investigation of consolidation procedures. The well-connected pore structure with minimum occurrence of dead-end pores suggests that the consolidation agent is very likely to flood the whole pore space.

Effect of Preparation Conditions on Application Properties of Environment Friendly Polymer Soil Consolidation Agent.

In order to improve the survival rate of transplanted seedlings and improve the efficiency of seedling transplantation, we developed an environmental friendly polymer konjac glucomannan (KGM)/chitosan (CA)/polyvinyl alcohol (PVA) ternary blend soil consolidation agent to consolidate the soil ball at the root of transplanted seedlings. In the previous research, we found that although the prepared KGM/CA/PVA ternary blend soil consolidation agent can consolidate the soil ball at the root of the seedling, the medium solid content of the adhesive was high, which affects its spraying at the root of the seedling. At the same time, the preparation temperature of the KGM/CA/PVA ternary blend was also high. Therefore, to reduce the energy consumption and the cost of the KGM/CA/PVA ternary blend soil consolidation agent in the preparation process, this paper studied the influence of preparation conditions on the application performance of the environmental friendly polymer soil consolidation agent. We aimed to reduce the highest value CA content and preparation temperature of the KGM/CA/PVA ternary blend adhesive on the premise of ensuring the consolidation performance of the KGM/CA/PVA ternary blend adhesive on soil balls. It was prepared for the popularization and application of the environmental friendly polymer KGM/CA/PVA ternary blend soil consolidation agent in seedling transplanting. Through this study, it was found that the film-forming performance of the adhesive was better when the KGM content was 4.5%, the CA content was in the range of 2–3%, the PVA content was in the range of 3–4%, and the preparation temperature was higher than 50 °C. The polymer soil consolidation agent prepared under this condition has a good application prospect in seedling transplanting.

Silica-Based Compounds as an Effective and Durable Consolidation Agent for Calcareous Stones

Silica-Based Compounds as an Effective and Durable Consolidation Agent for Calcareous Stones

Consolidation of volcanic tuffs with TEOS and TMOS: a systematic study

In this study, nine volcanic tuffs from Armenia, Germany and Mexico were treated with two commercially available consolidants on base of silicic acid ester, as well as different pretreatments with an anti-swelling agent and/or primer components. Prior to the treatment, the tuffs were analyzed regarding their petrography and mineralogy, with a greater focus on their clay mineral content. The effect of the consolidation was evaluated by comparative analyses of petrophysical properties and weathering behavior before and after the treatments. The main goals of this study were to identify a general suitability of different consolidating treatments for different types of tuff, evaluating tartaric acid as a primer component for tuff consolidation and to pursue the approach of finding a molecular answer for apparent tuff consolidation problematics, by testing a consolidation agent with smaller molecule sizes than current products on the market: tetramethoxysilane (TMOS).

Profile Control Using Fly Ash Three-Phase Foam Assisted by Microspheres with an Adhesive Coating

Foam-assisted steam flooding is a promising technique to alleviate gas channeling and enhance sweep efficiency in heterogeneous heavy-oil reservoirs. However, long-term foam stabilization remains problematic at high temperatures. Three-phase foam (TPF), containing dispersed solid particles, has been proposed to improve foam stability under harsh reservoir conditions. We fabricated a novel TPF system by adding ultrafine fly ash particles, as well as high-temperature resistant microspheres with an adhesive coating layer. This work aims at assessing the ability of the generated TPF in controlling steam channeling and enhancing oil recovery. Static and core flood tests were performed to evaluate foam strength and stability. Our results suggested a stronger foamability at a lower consolidation agent concentration, while a longer half-life period of foam and settling time of solid particles at a larger consolidation agent concentration were observed. Bubbles suspended independently in the liquid phase, with sizes varying from 10 to 100 μm, smaller than that of the conventional foam, suggesting a significant enhancement of foam dispersity and stability. The plugging rate was close to 90% when the temperature was as high as 300 °C, demonstrating a well-accepted plugging effect under high temperatures. A larger pore volume injection of TPF yielded a higher EOR in parallel cores, which substantiated the effectiveness of the three-phase foam system in sealing high-permeability channels.

Study on a new type of environment-friendly polymer and its preliminary application as soil consolidation agent during tree transplanting

Transplanting trees with rhizospheric soil is an important way to facilitate tree survival in the process of landscaping and reforestation. Traditional way to prevent looseness of rhizospheric soil is forming soil balls around the roots with bags, boxes or rope wrapping, which is cumbersome, laborious and easy to break. This study is aimed to develop a new type of degradable environment-friendly polymer as soil consolidation agent to facilitate tree transplanting. In this paper, the KGM/CA/PVA ternary blending soil consolidation agent was prepared by using Konjac glucomannan (KGM), chitosan (CA) and polyvinyl alcohol (PVA) as raw materials. Through the verification and evaluation, the clay and sandy soil can be consolidated and formed into soil balls by the ternary blend adhesive, which was convenient for transportation. The preliminary application of the ternary blend adhesive in the transplanting process of sierra salvia, Japanese Spindle (Euonymus japonicus) and Juniperus sabina ‘Tamaricifolia’ confirmed that the application of soil consolidation agent can effectively solve the problem that the root ball of seedling is easily broken in the process of transplant. And the application of soil consolidation agent has no adverse effect on the growth of transplanted seedlings. The research and development of ternary blending soil consolidation agent and its preliminary application in seedling transplanting will provide a new solution to solve the problem of soil ball breakage in the process of seedling transplanting. This is an important stage in the development of new seedling transplanting technology. Therefore, the research and development of soil consolidation agent is of great significance.

Investigations into the Application of Terahertz Radiation as a Control Possibility for Paint Layer Consolidations

ABSTRACT Terahertz radiation offers a means to monitor the consolidation of paint layers on panel paintings, and to corroborate the efficacy of such treatments. This project aimed to locate air voids underneath paint layers to determine the need to consolidate them, and subsequently to evaluate the success of the consolidation process itself. To this end experiments were carried out on mock-up samples and one original panel painting. Computed tomography was used for comparative testing of terahertz measurements. The results show that terahertz radiation supports the detection of air voids beneath the paint layer and moreover can help to determine the success of the treatment by the change in the reflectance spectra of the consolidated area. However, terahertz radiation cannot be used to identify the consolidation agent as an individual phase and the application of these results to assessments of the condition of panel paintings is less clear. While further research on original works of art is necessary to contextualise the findings, this work nevertheless has shown that terahertz radiation can be effective for monitoring and controlling consolidation treatments.

Synthetic calcium carbonate improves the effectiveness of treatments with nanolime to contrast decay in highly porous limestone

Three synthetized polymorphs of calcium carbonate have been tested in combination with the suspension of nanolime particles as potential consolidating agents for contrasting stone decay and overcome some of the limitations of nanolime agents when applied to substrates with large porosity. The modifications induced in the pore network of the Maastricht limestone were analyzed with microscopy and in a non-invasive fashion with small angle neutron scattering and synchrotron radiation micro-computed tomography. A reduction in porosity and pore accessibility at the micrometric scale was detected with the latter technique, and ascribed to the improved pore-filling capacity of the consolidation agent containing CaCO3 particles. These were found to be effectively bound to the carbonated nanolime, strengthening the pore-matrix microstructure. Penetration depth and positive effect on porosity were found to depend on the particle size and shape. Absence of significant changes in the fractal nature of the pore surface at the nanoscale, was interpreted as indication of the negligible contribution of nanolime-based materials in the consolidation of stones with large porosity. However, the results indicate that in such cases, their effectiveness may be enhanced when used in combination with CaCO3 particles, owing to the synergic effect of chemical/structural compatibility and particle size distribution.

Study on the Mechanism of Ionic Stabilizers on Shale Gas Reservoir Mechanics in Northwestern Hunan

The shale of the lower Cambrian Niutitang formation in northwestern Hunan is an ideal reservoir for shale gas. There is a close connection between borehole stability and drilling fluid in shale gas drilling. Ionic stabilizer is a new type of stratum consolidation agent that inhibits the hydration expansion of clay minerals and improves mechanical strength of the borehole. The traditional idea of pore wall protection is to use drilling fluid additives to prevent shale from interacting with water. However, ionic stabilizer can change the hydrophilic of clay minerals in shale, making the particles become hydrophobic and dense, therefore, the formation stability can be enhanced simultaneously. The material used in this paper is different from the normal ionic stabilizer, some chemical bonds that have been changed in the new material called enhanced normality ionic (ENI) stabilizer. This paper utilized the shale samples those obtained from Niutitang formation to study the connection between ENI and the mechanical properties of shale. Mechanical tests and microscopic pore tests were performed on different samples which were soaked in water and the ENI with different concentrations. It has been found through tests that ENI can inhibit the development of shale pores, and as the concentration increases, the inhibition increases. In addition, as the ENI concentration increases, the uniaxial compressive strength and Young’s modulus of the shale increase, and the ratio of stability coefficients decreases. It can be concluded that the ENI can improve the mechanical strength of carbon shale, and prevent the development of rock damage. Moreover, it can improve the ability of rock to resist damage, and enhance borehole stability initiatively.

Factors influencing the pumpability of unclassified tailings slurry and its interval division

Tailings consolidation and discharging technology is currently a popular means for disposing tailings in China. In this study, we describe a laboratory investigation of the unclassified tailings slurry from an iron mine and analyze the influence of the concentration, amount of consolidation agent, and types of consolidation agent on the pumpability in terms of the slump, slump flow, and bleeding rate of the slurry. The results indicate that an increase in concentration leads to a pronounced decrease in the magnitude of the slump, slump flow, and the bleeding rate. Compared with the consolidation agents P.O42.5 and P.S.A32.5, the new consolidation agent offers substantial advantages in promoting the pumping performance of the slurry. The concentration more strongly affects the slump, slump flow, and the bleeding rate of the slurry than does the amount of the consolidation agent. We also constructed the pumpability interval of the slurry on the basis of the slump and bleeding rate and accordingly determined the proportioning parameters of the slurry with a concentration of 75wt% to 79wt% and with a consolidation agent concentration of 2wt%. In addition, we discussed the pumpability mechanism of the slurry.

Study on Application Effect of Sand Consolidating Agent for the Slope of Highway Subgrade in Season Frozen Zone

In deep season frozen areas, the solidified layer is easy to be destroyed due to the influence of freeze‐thaw cycles after the surface layer of the sandy slope is solidified by chemical methods. In order to study the application effect of the new sand consolidating agent after solidifying sand body, the mechanism of strength formation was analyzed by scanning electron microscopy (SEM). The freeze‐thaw cycle tests were carried out on sand consolidating samples. The direct shear tests and unconfined compressive strength tests were carried out before and after freeze‐thaw cycles to analyze the freeze‐thaw resistance of sand consolidating samples. The sand consolidation agent was tested on‐site, and its strength was tested to observe its effect. The results showed that the adhesive membranes on the surface of sand particles were formed by the sand consolidating agent, which increased the cohesion and strength of sand particles. After freeze‐thaw cycle tests, the cohesion, internal friction angle, and compressive strength of the solidified sand gradually decreased with increasing freeze‐thaw cycles. The decreasing rate reduced from fast to slow and then tends to be stable. The failure mode of samples changed from brittle failure to plastic failure. The sand consolidating layer can effectively prevent collapse of the sandy slope. Combining with the external‐soil spray seeding, the sand consolidation layer is beneficial to the growth of plants.

Multi-elastic Datacenters: Auto-scaled Virtual Clusters on Energy-Aware Physical Infrastructures

Computer clusters are widely used platforms to execute different computational workloads. Indeed, the advent of virtualization and Cloud computing has paved the way to deploy virtual elastic clusters on top of Cloud infrastructures, which are typically backed by physical computing clusters. In turn, the advances in Green computing have fostered the ability to dynamically power on the nodes of physical clusters as required. Therefore, this paper introduces an open-source framework to deploy elastic virtual clusters running on elastic physical clusters where the computing capabilities of the virtual clusters are dynamically changed to satisfy both the user application’s computing requirements and to minimise the amount of energy consumed by the underlying physical cluster that supports an on-premises Cloud. For that, we integrate: i) an elasticity manager both at the infrastructure level (power management) and at the virtual infrastructure level (horizontal elasticity); ii) an automatic Virtual Machine (VM) consolidation agent that reduces the amount of powered on physical nodes using live migration and iii) a vertical elasticity manager to dynamically and transparently change the memory allocated to VMs, thus fostering enhanced consolidation. A case study based on real datasets executed on a production infrastructure is used to validate the proposed solution. The results show that a multi-elastic virtualized datacenter provides users with the ability to deploy customized scalable computing clusters while reducing its energy footprint.

One and two-dimensional NMR to evaluate the performance of consolidants in porous media with a wide range of pore sizes: Applications to cultural heritage

The conservation of historical buildings and outdoor cultural assets is of great value for the humankind. In this context, consolidation treatments represent a fundamental procedure to assure the survival of deteriorated cultural artefacts. For porous materials characterized by a wide distribution of pore sizes, adequate consolidation treatments require a product with a sufficient penetration depth and homogeneous distribution inside the unconsolidated substrate. Since water is one of the main deterioration agents of stone, the wettability of rock should also be minimized. A non-invasive and non-destructive technique, able to localize the consolidation agent and the water uptake, is needed to evaluate the efficiency of the treatments. NMR techniques are good candidates to satisfy this requirement.The present study aims at investigating the efficiency of two commercial consolidants, i.e. ethyl silicate and nano-silica, and a new formulated mixture of a fluoroelastomer and nano-silica by NMR relaxometry and MRI. The tested compounds showed adequate characteristics to be used as consolidating agents for highly porous carbonate rocks like limestone. All the products, in fact, penetrated uniformly and homogeneously into the porous structure, and preserved the connectivity of the stone matrix, as demonstrated by T2-T2 relaxation exchange experiments. Moreover, the hydrophilic behavior of commercial consolidants could be reduced, when the newly formulated agent was used. This study shows how the combination of different NMR techniques, applied in the time domain and with spatial resolution, is a powerful approach for evaluating the consolidation efficiency.

Sand Production Control in Sandstone Reservoirs Using a Modified Urea-formaldehyde Re

Several techniques have been used for sand production control in sandstone reservoirs.The main objective of this research is to present a suitable resin to be used as a consolidation agent in oil reservoirs. To achieve this purpose, urea-formaldehyde resin, phenol-formaldehyde resin, and modified urea-formaldehyde resin were selected to be studied. Core samples were made by the sand sample provided from the oil fields of southern parts of Iran with an average absolute permeability of 500-600 mD and an average porosity of 15-20% combined with various percentages of each resin. The core samples are tested for permeability, porosity, and compressive strength measurement. The results show that in the consolidation process with resin, modified urea-formaldehyde resin, as a consolidating agent, is more suitable than the other two types of resin. The consolidated sand samples of this resin had a compressive strength between 3100 and 4150 psi, permeability between 980 and 6823 mD, and porosity between 8 and 98%.

Application of methyltrimethoxysilane to increase dimensional stability of waterlogged wood

Abstract Conservation of historic wooden monuments, especially regarding waterlogged archaeological wood, is a complex, long-term, multi-stage and also a quite difficult process. The main problem is poor dimensional stability of such artefacts due to a high degree of wood tissue degradation and its significant saturation with water. Exposing wood to a natural drying process causes its shrinkage, cracking and irreversible deformation due to collapse. Therefore, the first stage of maintenance of waterlogged wooden objects is to replace the water filling cell lumina and cell walls with an appropriate consolidation agent that will protect wood against shrinkage, collapse and loss of shape. Silanes have so far been used mainly as additives for wood preservatives and coatings, increasing wood hydrophobicity or decreasing its hygroscopicity. Some silanes show resistance to biotic degradation. As confirmed in scientific reports, their ability to improve dimensional stability of contemporary wood makes them a potential agent for stabilisation of archaeological wood. The aim of the research was to determine the influence of methyltrimethoxysilane (MTMOS) treatment on the dimensional stability of waterlogged elm wood excavated from the Lednica Lake in the Wielkopolska Region. Freshly taken from the lake and still completely saturated with water, elm wood samples were treated with ethanol solution of 50% MTMOS by the vacuum-pressure impregnation method. Pre- and post-treatment dimensions of wood samples were measured and anti-shrink efficiency (ASE) was calculated. ASE values of elm wood treated with MTMOS varied from 69.4% to 94.5%, depending on the state of wood degradation. In case of reference wood samples treated with polyethylene glycol, ASE ranged between 96.1% and 100%. Taking into account the improvement of wood dimensional stability obtained, the aesthetic end result of the treatment and its properties of hydrophobicity and antifungal activity, the silane MTMOS can be considered as a potential agent for conservation of waterlogged wood and seems to be worth further study.

Thermo-Insulating Panels Based on Composite Structures from Vegetal Fibres and Polymeric Matrix

The study presents the experimental results on the use of composite structures based on vegetal fibres and polymeric matrix for obtaining thermoisolant panels for buildings. The use of the natural materials brings important contributions to human health but also to air protection. As vegetable fibers, hashed hemp, paper offals and recycled cellulose fiber were used in combination with formaldehyde resins and consolidation agent. The obtained samples were pressed at 50 bar and dried at environmental temperature. The testing of the samples was made for determining the coefficient of thermal conductivity, the base characteristic of the thermoisolant materials, and the thermal resistance. The obtained results led to the conclusion that these materials can be used as the filling material structure of the thermoisolant panels.

Digital radiography (DR) and imaging analysis for evaluating the penetration and distribution of organic substances used in wood conservation

Consolidation treatments are commonly employed in museum conservation studios for treating biologically deteriorated wooden cultural heritage objects. Impregnation using either a solvent/resin or a polymerizing system is an example of such an intervention, which is often difficult to describe in terms of its behavior within the object’s structure. A new simple method has been devised to evaluate the effectiveness of these impregnation treatments in terms of spatial distribution of consolidant solution. A combination of digital radiography and imaging analysis has permitted to evaluate the degree of penetration of a consolidant and to determine its location within the artifact by studying the X-ray images taken before, during, and after treatment. The adequacy of polymer solutions or their effectiveness as wood consolidants is properties which are often difficult to investigate due to limited visual access to the interior of the object. The proposed method provides an alternative way of studying these parameters through analysis of X-ray attenuation recorded on two images: taken before and after the conservation treatment. The resulting image is then converted into a two-dimensional map of consolidation agent within the object using a straightforward calibration procedure.