Changes In Physical Properties Research Articles

Gradual Solvent Quality Changes Induce Abrupt Changes in Interfacial Layer, Dispersion Structure, and Physical Properties of Polymer Nanocomposites

Gradual Solvent Quality Changes Induce Abrupt Changes in Interfacial Layer, Dispersion Structure, and Physical Properties of Polymer Nanocomposites

Analysis on temperature vacuum swing adsorption from wet flue gas carbon capture by using solid amine adsorbent with co-adsorption equilibrium models

Adsorption carbon capture has attracted extensive attention due to its low regeneration heat consumption, eco-friendly impacts and simplicity. However, there is a lack of comprehensive analysis of its energy consumption, economy and environment impact of adsorption carbon capture. This study aims to investigate the working performance using temperature vacuum swing adsorption (TVSA) from wet flue gas carbon capture utilizing co-adsorption equilibrium models for metal–organic framework (MOF) based amine materials. TVSA model is then carried out in terms of the continuous operational state, the dynamic changes in physical properties inside the bed, and the differences in properties at different positions within the bed layer. It is found that they often cannot simultaneously meet high CO2 recovery rates, productivity, and equivalent work. The analysis reveals that the optimal conditions, namely an adsorption temperature of 318 K and a CO2 component of 0.02 kmol during desorption, collectively result in reduced equivalent work and heightened productivity. The maximum productivity could reach 46.35 kg·m−3·h−1 for 5.6 v% water content and 308 K adsorption temperature. It is demonstrated that temperature vacuum swing adsorption for wet flue gas carbon capture using MOF based amine adsorbent is quite promising in terms of energy consumption and CO2 productivity in the future.

Effects of long-term saline water irrigation on soil salinity and crop production of winter wheat-maize cropping system in the North China Plain: A case study

Fresh water shortage is a major problem for grain production in the low plain around Bohai Sea in the North China Plain. Relative abundance of shallow saline groundwater could serve as an alternative water resource for use during dry seasons. A continuous 8-year field study was conducted from 2015 to 2023 to assess the effects of salt content in irrigation water on soil salt accumulation and crop production. Fresh water (FW) with electrical conductivity (EC) at 1.6 dS/m and three levels of saline water (SW) with EC at 4.7 (SW1), 6.3 (SW2) and 7.8 dS/m (SW3) were used for irrigation. Results showed that a single irrigation event at the jointing stage of winter wheat increased grain production averagely by 18.6 %, 22.5 %, 12.9 % and 9.5 % compared with a rain-fed treatment (RF) under FW, SW1, SW2 and SW3, respectively. With an additional irrigation applied at flowering stage, both irrigations using FW increased the yield by 28.6 %, and both irrigations using SW2 increased the yield by 19.3 % compared with RF. Negative effects of salt on winter wheat overshadowed the positive effects of increased water supply under two irrigations both using SW. With an irrigation at maize sowing and the subsequent summer rainy season, the yield of maize following winter wheat was not affected by a one-time SW irrigation to the previous crop, but showed a 5.3 % yield reduction when two irrigations of SW were applied. There was no apparent salt accumulation in the top 1 m of the soil profile, but a slight increasing trend in the salt content in the 1–2 m layer of the soil profile under SW2 and SW3 irrigation. No apparent changes in soil physical properties were observed for continuous application of SW. It was suggested that SW with EC not exceeding 6.3 dS/m should be applied for a single irrigation during the winter wheat season. This practice could alleviate the fresh water shortage in this region and allow for the maintenance of a relatively stable yield of winter wheat and maize without the risk of salt accumulation in the soil.

Effect of alkali treatment and fungal degradation on the nanostructure and cellulose arrangement in Scots pine cell walls – A neutron and X-ray scattering study

Research on new conservation treatments for historical wood requires considerable amounts of appropriate wood material, which is hard to acquire. Thus, we produced biologically and chemically degraded model wood that could be used as a representative material in future research on consolidating agents. Using chemical composition determinations, we found that fungal decay targeted mainly polysaccharides, while alkaline treatment mostly reduced hemicelluloses and lignin content. X-ray and neutron scattering showed that all decayed samples had increased disorder in microfibril alignment and larger elementary fibril cross-sections, and alkaline-treated samples had much larger elementary fibril spacing compared to those decayed by fungi. These nanoscale and chemical differences correlate with physical property changes. For example, decreased cellulose crystallinity and increased disorder of the microfibrils in degraded cell walls likely contribute to the lower elastic moduli measured for these cell walls. The obtained data improves understanding of how degradation alters wood structures and properties across length scales and will be valuable for future studies focusing on archeological wood. Moreover, it leads to the conclusion that it is more appropriate to develop treatments that consider not only spatial variability and degree of wood degradation but also the corresponding molecular and nanoscale changes in the cell walls.

Impact of antiaging additives on the conventional properties of bituminous binder

Aging of binders is a complex phenomenon which reduces the longevity of flexible pavements. Aging involves change in physical, chemical, and morphological properties of binder which makes the binder brittle and highly susceptible to fatigue and thermal cracking. Antiaging additives enhance the service life of flexible pavements by reducing the impact of aging on the performance of binders. An iterative approach is essential to identify the optimal dosage of antiaging additive necessary to counteract the aging effects on binder. The present study aims to evaluate the mixing conditions for uniform dispersion of carbon black and hydrated lime within the binder matrix and thereby evaluate the impact of incorporating these antiaging additives on the conventional properties of binder. For this purpose, varying proportions of carbon black and hydrated lime are added to VG 30 binder and is subjected to softening point, ductility, and penetration tests. The optimal dosage of carbon black and hydrated lime is found to be 6 and 12% respectively based on their significant effects on the conventional properties of the binder. An optimal mixing duration of 60 and 75 min ensures uniform dispersion of carbon black and hydrated lime within the binder matrix at a mixing temperature of 120 °C and a speed of 1000 rpm thereby producing a homogenous binder mastic. Incorporation of antiaging additives up to the optimal dosage enhances the softening point whereas decreases the penetration and ductility of binder. The increase in softening point of binder with incorporation of carbon black and hydrated lime signifies enhanced resistance to rutting and permanent deformation of binder, whereas the reduction in ductility and penetration of binder with incorporation of carbon black and hydrated lime signifies the reduced susceptibility of binder to environmental factors such as temperature fluctuations, UV radiation, and oxidation. The surface texture of the additive influences the ability of binder adsorption, which subsequently affects the rheological properties of binder mastics. Significant improvement in conventional properties of binder with incorporation of carbon black and hydrated lime paves a viable and cost-effective solution for engineering application as it has a subsequent effect on the rheological properties of binder.

Electrochemical Reduction Behavior of PO43– Ions in Molten CaCl2

This work focuses on the electrochemical reduction behavior of PO43– ions in molten CaCl2 at 1123 K, aiming to develop a next-generation process for producing white phosphorus (P4) through electrolysis of dissolved PO43–. Results from cyclic voltammetry indicate a shift for the electrochemical reduction of PO43– from a reversible reaction to a quasi-reversible one as the potential scan rate increases. The detachment rate of P4 gas was found to be higher at the graphite electrode compared to Mo and W electrodes. The apparent diffusion coefficient of PO43–, determined from chronoamperometry and chronopotentiometry at a graphite electrode, ranges from 1.43 to 2.26 × 10–4 cm2 s–1. Additionally, an increase in the concentration of O2– was found to decrease the detachment rate of P4 gas, likely due to changes in the melt's physical properties. However, the increase in O2– up to 0.30 mol % does not significantly affect the diffusion of PO43–. This study provides valuable insights into the electrochemistry of PO43– in molten CaCl2 and offers a theoretical guidance for the technology development of P4 production through electrolysis.

Steady and transient modeling of dye-sensitive solar cells: The impact of electrode thickness and dye specifications

Investigating the impact of dye compounds on cell performance is crucial for advancing dye-sensitized solar cells (DSSCs). This research focuses on the sensitivity analysis of the effect of critical parameters to enhance DSSC efficiency using a thermo-electric numerical model. These parameters include dye types, trapping parameters, diffusion coefficients, and photoanode thickness. When the type of dye changes, in fact, both physical and chemical properties (molar absorption coefficient, etc.) Change, but to avoid the complexity of solving the equations and only to evaluate the effect of the absorption wavelength range on the cell performance only changes in physical properties are considered. The model calculates steady and transient currents under actual weather conditions and sunlight. It incorporates time/space-dependent relationships for increased accuracy and examines electron, iodide, and triiodide ion interactions under varying environmental conditions. Key concepts include the quasi-Fermi level and the multiple trap model, assuming that trapping processes are faster than electron transport and recombination. The results showed that increasing the trapping parameter can affect the transient current behavior, also increasing the thickness of the photoanode and the wavelength range of the dye increases the efficiency of the cell, so that the N749-BD provides the best performance. The findings provide insights into current–voltage characteristics, electron production, and the effects of photoanode thickness and dye types on cell performance, offering pathways for optimizing DSSC technology.

Reconstituted Bamboo Scrimbers Prepared from Bambusa tulda with Phenol Formaldehyde (PF) Adhesive for Structural Applications

Abstract: This study investigates the physical and mechanical properties of reconstituted bamboo scrimbers prepared from Bambusa tulda bamboo, also known as Indian timber bamboo or Bengal bamboo. The preparation involves varying pressure levels (21.0, 24.5, 28.0, and 31.5 kg/cm2 ) with phenol formaldehyde (PF) adhesive using a hydraulic hot press. The study explores the change in mechanical and physical properties of bamboo scrimbers under varying specific pressures, which significantly reduces moisture content, increases density, and enhances resistance to water absorption and swelling. Mechanically, it improves properties such as modulus of rupture (MOR), modulus of elasticity (MOE), compression parallel to the grain, hardness, and screw-holding capacity. The results position the reconstituted bamboo scrimbers in the super group (IS:3629-1986) in stress grading (MOR & MOE) at all tested specific pressures, surpassing raw bamboo strength properties as well as conventional standard timber, including Teak (Tectona grandis). The results demonstrate remarkable properties comparable to species like Sal (Shorea robusta), Khair (Acacia catechu), and Teak (Tectona grandis) in various mechanical properties. This research highlights the potential of bamboo-based materials over conventional timber in construction and for sustainable development. Future studies on different adhesives and pressure levels could further enhance their economic sustainability.

Effects of soil heating changes on soil hydraulic properties in Central Chile

Wildfires are natural phenomena for most ecosystems on Earth. Many soil properties are impacted by fire, including soil hydraulic properties. We used a laboratory experiment to replicate the temperatures reached by a natural wildfire and documented the effects on soil hydraulic properties. This study hypothesizes that the impact of heating on soil hydrological properties can be explained by the interaction of a number of variables especially organic matter content (OM), cation exchange capacity (CEC), texture, pH, and electrical conductivity (EC). The main objective of this study is to explore the interconnections between soil hydraulic, chemical, and physical properties, focusing on understanding how these relationships change across different ecoregions and temperatures. Sixteen soils were collected across 16 sites susceptible to forest fires in the Central Zone of Chile and heated to 100 °C and 300 °C for two hours. These sites were representative of two distinct ecoregions: the Chilean Matorral (CM) and the Valdivian Temperate Forests (VTF). Chemical, physical, and hydraulic soil properties were measured before and after heating. At 100 °C, there were no significant changes in chemical, physical, or hydraulic soil properties. At 300 °C, significant changes were observed in most soil properties in soils from both ecoregions. The OM content and CEC decreased, whereas pH and electrical conductivity increased. In addition, clay content and water aggregate stability (WSA) decreased, while all hydraulic properties increased their values. The aforementioned results demonstrate that infiltration increased after the soil was heated. This can be attributed primarily to decreases in clay content. At the same time, the water repellency (R) index decreased, allowing water to more easily wet the soil particles. Correlations revealed that CEC and clay are the main factors ruling soil hydraulic properties at all temperatures. Clay mineralogy also contributes to the soil hydraulic behavior observed. Nonlinear models were developed to estimate hydraulic properties at 100 °C and 300 °C, using the main soil properties. The models illustrated that the soils of the CM ecoregion, which are characterized by lower OM and influence of clay/CEC ratio, would be less affected by fire compared to the soils of VTF. The water holding capacity would decrease in both ecoregions. However, due to the greater changes in OM and clay in VTF, the impact would be greater than in CM.11Ca2+ = Calcium cations (meq/ 100g); CEC = Cation exchange capacity (meq/ 100g); CM = Chilean Matorral; EC = Electrical conductivity (μS/cm); I = Cumulative infiltration (cm); K = Unsaturated hydraulic conductivity (mm/h); K+ = Potassium cations (meq/ 100g); Ks = Saturated hydraulic conductivity (mm/h); Mg2+ = Magnesium cations (meq/100g); Na+ = Sodium cations (meq/100g); OM = Organic matter (g/100g); R index = Water repellency index; Se = Ethanol sorptivity (cm/s05); Sw = Water sorptivity (cm/s05); VTF = Valdivian Temperate Forest; WSA = Water-stable aggregates (%).

Changes in the physical properties of fallow lands during their regeneration

The change of physical and mechanical properties of soil depending on the methods of its cultivation has been studied. The experiments were carried out in the Novosibirsk region from April to September 2023. To study the structure of the soil, a soil section was made to a depth of 0.7 meters. It was determined that the soil at the experiment plots was gray forest, the thickness of the turf layer was on average 10 cm, the depth of the humus horizon 25–27 cm, a layer of sandy loam was observed under the humus layer. Fallow land cultivation was carried out by the tillage combine AKP-2.5N with MTР-80L tractor and the working width of 1.8 meters. The working body of the AKP-2.5N was made in a form of a straight rack with a blade measuring 410 mm, in addition, a small screen was installed on the rack. The unit provides for the installation of the rollers with a size of 600 mm. To determine the operating modes of the unit, studies were carried out in the soil channel. It was found that the operating speed of the unit with installed screen should be no more than 2.22 m/s or 8 km/h. The conditions of the experiment: gray forest soil, air temperature not lower than 10 0C; air humidity no more than 70%; relative humidity of at least 18%, wind speed not higher than 2 m/s; the average length of the rut is not less than 70 m and without stones on the field. It has been concluded that the most rational way to introduce fallow gray forest soils into agricultural circulation is to treat them with AKP-2.5N units with working bodies equipped with blades. After three treatments, the content of soil particles less than 10 mm is up to 93.1%, the soil absorbs moisture faster and reduces the hardness to 15 kg/cm2, which corresponds to the hardness of the soil of the field in rotation. Equations of regularity of changes in the fractional composition of soil with a size of less than 10 mm and more than 50 mm depending on the timing and number of treatments have been obtained.

An accurate identification and spatial characterization method for the development degree of preferential flow paths in water-flooded reservoir

Water flooding is one of the most important methods for oil field development, It accounts for more then 70% of China's crude oil production. However, in the progress of water flooding, preferential flow paths often formed between oil and water wells, which seriously restricts production rate. How to effectively identify the preferential flow paths has become the key to improving the effect of water flooding. In this paper, to solve the problem of difficult identification of preferential flow paths in reservoirs, through the change of core seepage law with high pore volume water flooding experiment, parameters such as multiple of water flux, change value of permeability, and water saturation were selected for analysis. The weight coefficient for each parameter was determined by the variation coefficient method of objective weight. Subsequently, a comprehensive reservoir identification index was obtained by weighting each parameter, which was used to describe the development degree of the preferential flow paths. Finally, quantitative criteria of preferential flow paths were given. The spatial characterization of preferential flow paths was realized by post processing of the Eclipse software. The new method for identifying preferential flow paths fully considers the changes in physical properties and fluid mobility of water-flooded reservoirs. The results of the new applied to a typical water-flooded reservoir in the Bohai Bay Basin show that the preferential flow paths calculated by the new method were highly consistent with the judgment results of tracers. It can accurately and quickly identify the preferential flow paths. This study provides a scientific basis for adjusting measures of water-flooded reservoirs to further enhance oil recovery. Moreover, the new method holds broader prospects for application in the field of porous media transport.

Preparation, optical properties, room temperature ferromagnetism, and mechanism of ordered nanotube-like tantalum oxide films

Physical property changes caused by defects have recently attracted significant attention due to their potential applications in sensors, spintronic devices, and multifunctional memory. Due to their numerous surface defects, this study fabricated ordered Ta2O5 nanotube (NT) thin films on Ta foil through an anodization technique. Then, the oxygen bubble model was applied to explain the formation of NTs from the perspective of lattice orientation. Furthermore, this study investigated influence of anodization duration and annealing treatment on the crystal structure, optical properties, and magnetic behavior. Notably, room-temperature ferromagnetism was observed in the as-prepared Ta2O5 NTs for the first time. After annealing in an argon atmosphere, the band gap of the sample decreased, accompanied by an increase in ferromagnetism. The underlying mechanism for this phenomenon was elucidated using a hydrogen-like impurity model. Consequently, this study on the magnetism of Ta2O5 NTs holds excellent potential for expanding their application in spin electronic devices.

Evaluation of changes in soil physical properties 20 years after skidding operations

ABSTRACT Soil degradation can negatively impact its physical and chemical properties over the long term. We investigated the natural recovery of physical properties of disturbed soils on an abandoned machine operating trail in a deciduous mountain forest in northern Iran. The machine operating trail hadn’t been used for the last 20 years. Dry bulk density and total porosity were assessed for three levels of traffic intensity (light, moderate, and heavily trafficked trails) and two levels of slope gradients (gentle, ≤20%, and steep, >20%), in four different soil depths (0–10, 10.1–20, 20.1–30, and 30.1–40 cm) as well as in undisturbed (control) areas. Over the course of the 20-year recovery period, it was observed that in the depth intervals of 0–10, 10.1–20, 20.1–30, and 30.1–40 cm, trails subjected to heavy traffic on gently sloping terrain displayed mean values that exhibited an increase of 78%, 62%, 55%, and 47% in bulk density, respectively, and a decrease of 27%, 26%, 28%, and 27% in total porosity, respectively, when compared to undisturbed soil. In the case of steep slopes, analogous assessments indicated an increase of 82%, 69%, 39%, and 31% in bulk density, respectively, and a reduction of 28%, 29%, 26%, and 24% in total porosity, respectively, within the aforementioned depth intervals. However, in the case of lightly trafficked trails situated on gentle slopes, there was a discernible amelioration in surface soil compaction. Our findings consequently suggest that the natural recovery of soil physical properties in the study area extends beyond the examined timeframe of twenty years.

Multi-scale nonlinear reservoir flow simulation based on digital core reconstruction

During the exploitation of oil and gas reservoirs, changes in reservoir physical or fluid properties will lead to alterations in formation seepage capacity, subsequently impacting the productivity of oil and gas wells. Therefore, it is crucial to evaluate the variations in reservoir physical and fluid properties as well as their influence on oil and gas well productivity during reservoir exploitation.It employs a descriptive approach to investigate cross-scale (i.e., micro-scale → small-scale → large-scale) fluid seepage phenomena in water flooding. By leveraging digital core reconstruction technology and focusing on micro-pore network simulation, it establishes an analytical framework for studying cross-scale seepage fields, facilitating the exploration of the micro-seepage mechanism that governs non-homogeneous water flooding's impact on liquid production capacity within a reservoir. Integrating constraints from micro-pore network simulation and small-scale core displacement test data, while considering macro-heterogeneity near wellbore areas as flow unit divisions and superposition bases within large-scale reservoirs, it reveals the nonlinear flow characteristics of changes in liquid production capacity in water-flooding oil reservoirs based on microscopic digital core analysis. This approach aligns with findings from small-scale core testing and sweep coefficient correction while also addressing the non-uniform distribution characteristics of physical parameters within large-scale reservoirs.By integrating permeability field characteristics at three levels, this approach optimizes its technical advantages in describing dynamic permeability fields at each level, thereby facilitating precise prediction of water drive oil development effects.

The difference in the photosynthetic characteristics and soil moisture of different varieties of sweet cherry (Prunus avium L.)

Sweet Cherry (Prunus avium L.) is a highly sought-after fruit in the global market due to its nutritional value and appealing sensory characteristics. This paper investigated the indicators of photosynthetic physiological characteristics and changes in soil physical properties of different varieties of sweet cherries grown in the Loess Plateau region, which strengthened the research on the ecological aspects of photosynthetic physiology of sweet cherries. By analyzing the characteristics and similarities of photosynthesis processes in different varieties, the results were obtained to showed that most of these sweet cherries showed obvious inhibition of photosynthesis at noon. The daily net photosynthetic rate (Pn) variation graph displayed a typical bimodal curve, with the lowest values occurring successively at 12:00 pm and 14:00. The Pn of sweet cherry is mainly influenced by water use efficiency (WUE) and transpiration rate (Tr). Rainier and Summit exhibited the best performance in the daily mean of Pn due to the interplay between photosynthetic physiological and ecological factors. To affect the photosynthesis of sweet cherries, covering the greenhouses with plastic film would impact the changes in light intensity and temperature. The crop management mode of uniform mulching and drip irrigation can affect the water content of different soil depths, leading to a reduction in Pn due to the varying WUE and Tr of different varieties of sweet cherries. The order of photosynthetic physiological characteristics of different varieties of sweet cherries, as revealed by principal component analysis, was as follows: Rainier > 4YJimei > 2YTieon > 4YTieon > Summit > Jimei > Tieon > Hongdeng. These results provide a scientific theoretical basis for the introduction, promote the production of sweet cherries and provide a new understanding of the plantation management mode.

A Study on the Thermal Physical Property Changes in Formation Rocks during Rapid Preheating of SAGD

The incorporation and application of SAGD rapid preheating technology effectively solve the problem of the long preheating cycle in the SAGD steam cycle. The thermal properties of reservoir rocks are an important factor affecting the heat transfer law governing their formation during the rapid preheating process of SAGD. During the rapid preheating process of SAGD, the expansion of the reservoir and the steam cycle process will cause changes in the pore permeability, oil-water saturation, and temperature of the reservoir rocks, which will inevitably lead to differences in the changes that occur in the thermal properties of the reservoir rocks, compared to those under the influence of a single factor. In this study, experiments were conducted to determine the thermal properties of reservoir rocks under the combined influence of pore permeability, oil-water saturation, and temperature, quantitatively characterizing the changes in the thermal properties of reservoir rocks. Using the orthogonal method to design and carry out experiments for determining the thermal properties of reservoir rocks, the main factors affecting the thermal properties of reservoir rocks and the significance of each factor’s impact on the thermal properties of reservoir rocks were determined through intuitive analysis and variance analysis of the experimental results. Finally, a regression equation that can characterize changes in the thermal properties of reservoir rocks under the influence of multiple factors was obtained through multiple nonlinear regressions of the experimental results.

The Effect of Chemical Disinfectants on Maxillofacial Silicone With the Addition of Silver Nanoparticles: An Original Research.

Background and objective Silicone has emerged as the most widely accepted material for facial prosthesis fabrication.However, silicone materials have certain limitations. Several techniques have been investigated to lessen the degradation of the polymer, such as the use of nanoparticles and nano-oxides, etc.In this study, we aimed to evaluate the effect of various chemical disinfectants on color stability, hardness, and surface roughness of maxillofacial silicone, after the addition of silver nanoparticles. Materials and methods This was an in vitro study carried out in the Department of Prosthodontics, Sharad Pawar Dental College and Hospital; 80 samples of maxillofacial silicone incorporated with silver nanoparticles (in a concentration of 20 ppm) were fabricated in a mold of 3 x 10 mm dimension disc. The samples were then tested for surface roughness (using a digital roughness tester), Shore A hardness (using a durometer), and color stability (using a spectrophotometer). The samples were then classified into four groups according to various disinfectants used: sodium hypochlorite (1% w/w), chlorhexidine gluconate (0.2%), and neutral soap, and distal water was deemed the control group. After 48 hours, the samples underwent retesting to assess for changes in readings under the same parameters (i.e., surface roughness, Shore A hardness, and color stability)to obtain results, i.e., the samples were testedafter fabrication, before immersion, and 48 hours after immersion in disinfectants. Results When taking into account the surface roughness, the maximum roughness value was observed in the sodium hypochlorite group and the least roughness value in distilled water (mean % change of 38.359 to negligible change in the distilled water group). As for the Shore A hardness, the maximum hardness value was seen in the sodium hypochlorite group and the least hardness value in distilled water (mean % change of 15.780 to 2.125 in distilled water). Regarding color stability, the maximum increase in color values was seen in the sodium hypochlorite group (mean: 2.4) followed by the neutral soap group (mean: 1.653); the chlorhexidine gluconate group (mean: -0.287)showed the maximum decrease in color value from the initial to the final phase. Conclusions Based on our findings, surface roughness altered the most when samples were immersed in 1% sodium hypochlorite disinfectant and the leastwhen samples were immersed in neutral soap disinfectant. Shore A hardness altered the most when samples were immersed in 1% sodium hypochlorite disinfectant, but altered the least when samples were immersed in neutral soap disinfectant. Color stability altered the most when samples were immersed in neutral soap disinfectant, but altered the least when samples were immersed in 0.2% chlorhexidine gluconate. Disinfection with neutral soap seems to lead to fewer changes in physical properties (i.e., surface roughness and Shore A hardness) and hence is recommended as a disinfectant for silicone prosthesis. However, our study also showed that 0.2% chlorhexidine gluconate had the least effect on the parameter of color stability, and hence it could be the disinfectant of choice for prostheses with high esthetic requirements.

Experimental study on the effects of composite reinforcement of ionic soil stabilizer and sand on bentonite

This paper utilizes both the ionic soil stabilizer (ISS) and sand to strengthen bentonite, as ISS effectively reduces its expansive properties and sand rapidly improves its strength to reduce cracks. Various experiments are conducted to analyze the changes in physical and mechanical properties of the bentonite strengthened by ISS-sand (ISB). The results show that not only do the sand particles enhance the strength of bentonite, but also the ISS significantly reduces its expansibility. Furthermore, the mass ratio of sand to bentonite has different effects on the unconfined compressive strength (UCS) and the freeze-tolerance of sand-reinforced bentonite (SB) and ISB. These findings suggest that a comprehensive consideration of the sand mixing rate is necessary when implementing ISS reinforcement on natural expansive soil.

Enhancing Soil Stability through Innovative Microbial-Induced Calcium Carbonate Techniques with Sustainable Ingredient

Expansive soil poses significant challenges for civil engineers, leading to structural damage, particularly in lightly loaded structures. This study employs an innovative and sustainable recipe to stabilize highly expansive soil using the Microbial-Induced Calcium Carbonate Precipitation (MICP) technique by substituting conventional ingredients with olive mill wastewater and hydrated lime. A series of laboratory tests were performed to evaluate the improvement in Atterberg's limits, Free Swell, Unconfined Compressive Strength (UCS), and pH, in addition to a series of qualitative measurements, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Optical Microscopic Images, and bacteria growth rate. Different mellowing periods and different cementation concentrations were used. The proposed recipe results showed a 50% reduction in the soil's free swell value. The UCS of the treated soil using the proposed recipe was eight times that of the untreated soil and twice that of the soil treated with the traditional recipe. The SEM images showed flocculation and aggregation in the soil particles, with the voids becoming smaller and filled with calcium carbonate (CaCO3). The XRD results showed the formation of new CaCO3particles. The optimized recipe demonstrated remarkable enhancement improvement and significant changes in soil physical properties and microstructure. Doi: 10.28991/CEJ-2024-010-08-08 Full Text: PDF

Tunability of Sb2Se3 phase change material for multi-domain optoelectronics

Phase change materials play an essential role in the development of tuneable optics by overcoming the limitations possessed by conventional optics due to their static behaviour. Due to their non-volatile nature, chalcogenide materials attained attention beyond other phase change materials. Antimony-based chalcogenides are promising due to low absorption loss, optimal refractive index change, and compatibility with silicon integration. This study optimises near-stoichiometric sputtered Sb2Se3 thin films and investigates their compositional, physical, and optical properties change by thermal, optical, and electrical stimuli. We further extend the investigation to the induced intermediate states in the Sb2Se3 thin film for multi-bit operation for tunable photonics and phase-change memory with a current switching ratio of 104 during a phase transition. The findings are integral to the realisation of high-capacity optical switches and routers, displays with larger colour distribution, and photonic memories with high computational capabilities.