Wet Test Research Articles

The influence of permeability and heterogeneity on chemical flooding efficiency and remaining oil distribution—based on NMR displacement imaging

To investigate the impact of permeability and heterogeneity on oil displacement efficiency and remaining oil distribution of chemical flooding, three groups of high and ultrahigh permeability core samples from an ultrahigh water-cut oilfield in western China were selected as the research objects in this study. High-pressure mercury injection, scanning electron microscopy, wettability test, and other methods were used to characterize the reservoir properties of core samples. Six groups of experiments were performed using the nuclear magnetic resonance (NMR) displacement imaging technology to simulate the oilfield development process considering the economic benefits. The displacement stage with the best oil displacement effect in the process of waterflooding, chemical flooding and then waterflooding was defined, and the control effect of permeability and heterogeneity on the improvement of oil displacement efficiency by polymer-surfactant binary flooding was discussed. The distribution position of remaining oil in different displacement stages was quantitatively and visually displayed, and its control factors were revealed. The research shows that during the simulation process of first waterflooding followed by chemical flooding and then waterflooding in the oilfield, the T2 spectrum signal amplitude increases the most in the two stages, one is from saturated oil flooding to 50% water cut and the other one is from 95% water cut to the end of 1 PV polymer flooding. The oil displacement efficiency increases the most, and the oil is primarily discharged from pore throats larger than 90 ms (or with pore throat radius of 8.37 μm). Compared with heterogeneity, permeability plays a more obvious controlling role in improving the oil displacement efficiency of polymer-surfactant binary flooding. The influence of fingering phenomenon on the distribution of remaining oil is most obvious in the second waterflooding, and the distribution of remaining oil with polymer slug is more obviously affected by the fingering phenomenon than that with polymer-surfactant slug. The study results provide theoretical guidance for tapping the remaining oil potential of old oilfields with high to ultrahigh permeabilities.

Surface modification of grey cast iron by laser cladding for automotive brake disc application

In this research, Laser Cladding (LC) of three different alloys powders, two iron-based (AISI 4140 and SS420) and a Cobalt-based (Stellite 6) was performed on a Grey Cast Iron (GCI) substrate. The Stellite 6, SS420, and AISI 4140 cladding samples were tested against a semi-metallic composite brake pin for friction and wear study using a pin-on-disc friction test rig (under dry-sliding conditions). The surface wettability tests were performed on GCI, and cladding discs showed Stellite 6 and AISI 4140 were hydrophobic while SS420 and GCI were hydrophilic. Stellite 6, SS420, and AISI 4140 had surface hardness values of 542.16 HV1, 689.56 HV1, and 719.50 HV1, respectively. The friction test indicated that AISI 4140 and Stellite 6 cladding discs could produce a stable Coefficient of Friction (CoF) and friction layer coverage. SS420 could not maintain a constant CoF for the entire test duration as the plowing effect of the wear particles damaged the friction layer created on its surface. Stellite 6's average CoF value was closest to that of the GCI disc, whereas AISI 4140 and SS420 were found to have a higher average CoF. The LC on grey cast iron reduced its wear rate, with AISI 4140 being the most wear-resistant cladding, followed by SS420 and Stellite 6, respectively. All three cladding layers exhibited three-body abrasive wear, with the rolling mechanism dominating the AISI 4140 surface and sliding on the remaining two.

Enhancing the hydrophobicity of the mineral wool through surface modification with organo-silane

Mineral wool materials are consistently preferred material to be used for building thermal insulation because of their low heat conductivity, making energy-efficient structures impossible to construct without highly insulating thermal envelopes. A mineral wool with a hydrophobic external surface could be used for several applications where hydrophobicity would be helpful. Organo-silanes are one of the most promising materials to impart hydrophobic character to varied surfaces to achieve performance properties such as dust-resistant coatings on building glass, solar panels with self-cleaning surfaces, biofouling resistant paints, self-cleaning car windshields etc. In this study, mineral wool was treated with methyltrimethoxysilane (MTMS) to achieve hydrophobic surfaces.A Fourier Transform Infrared Spectrometer is used to confirm the successful deposition of organosilane/siloxane networks on glass wool fibre surfaces. The hydrophobicity of treated wool was assessed and quantified using a contact angle measurement. Contact angle measurement was used to quantify the hydrophobicity of treated wool. The thermal conductivity of treated mineral wool fiber was calculated using the portable Lee's disc method. To determine the thermal stability and crystallinity of the treated wool, X-ray diffraction spectroscopy and thermogravimetric analysis were used, respectively. The treated mineral wool exhibited excellent thermal stability up to 800 °C, and wettability tests proved the treated surface highly hydrophobic, allowing water droplets to roll off with contact angles up to 134.9°. Surface modification reduced thermal conductivity by 20%, showing good thermal resistance. Here, we show easy and sustainable methods of treating mineral wool surfaces, which can serve as a thermal insulation option under humid conditions.

A Cleaner Pavement Preventive Maintenance Approach: Performance and Emission Impact Analysis of Slurry Surfacing Containing Electric Arc Furnace Slag

Incorporating Electric Arc Furnace Slag (EAFS) into construction materials such as hot-mix asphalt and Portland cement concrete has shown increasing wear and polishing resistance while reducing solid waste and mitigating the carbon footprint of construction engineering. Pavement surface treatment is one of the most used pavement preservation approaches. The slurry surfacing (SS) technique provides the most hot-mix asphalt-like surface texture among the surface treatment techniques. This study aimed to investigate the feasibility of using EAFS for SS by incorporating various amounts of EAFS and then analyzing the treatment's performance and the resulting carbon footprint reduction. Performance tests of SS, including the wet track abrasion test and loaded wheel test, were performed to evaluate SS's abrasion and deformation resistance. Aggregate packing degree and bonding strength based on the surface charge were also considered to understand the mechanism affecting the performance. The corresponding reduction in carbon footprint is then analyzed using the tiered hybrid life cycle assessment method to understand further the benefits of using EAFS in SS. The results revealed that mixtures incorporating EAFS could be carefully designed to perform better by increasing the packing degree and bonding strength. Also, adding EAFS into SS increased abrasion resistance by up to 18.2%, rutting resistance by up to 72.8%, and reduced the carbon footprint by up to 39.6%.

Plasma electrolytic oxidation of tantalum in an aluminate electrolyte: Effect of cathodic polarization and frequency

The effect of cathodic polarization on plasma electrolytic oxidation (PEO) of the refractory metal of tantalum is investigated in 10 g/l NaAlO2+2 g/l KOH under 1000 and 100 Hz. Ceramic coatings are formed under various cathodic-to-anodic current densities ratios (R = jc/ja) of 0, 0.6, 1.3 and 2.3. For PEO under 1000 Hz, the plasma discharges intensify with the increase of R from 0 to 1.3, with optical emission from Ta being detected at later stage of PEO under cathodic polarization. However, excessive R ratio of 2.3 has caused early extinguishment of the plasma discharges. Correspondingly, thicker coatings are formed as the R ratio increases from 0 to 1.3, and the coating under R = 1.3 exhibits a most porous outer layer. A thin and compact coating is formed under R = 2.3. It is also found that the application of cathodic polarization increases the Na content in the resultant coatings, with a new crystalline phase NaTaO3 being formed under R = 2.3. Cathodic polarization also decreases the corrosion resistance of the coatings. Surface wettability tests show that the coatings formed under R = 1.3 are the most hydrophilic. PEO under 100 Hz shows some differences in discharge and coating formation. Larger sized discharges are also observed at the later stage under R = 0.6, but Ta species are detected at a delayed time. For the R values of 1.3 and 2.3, patches of soft sparking occur on the sample surface, leading to non-uniform coatings. This study shows that both cathodic polarization and frequency significantly affect the PEO process. Moreover, compared with the PEO of Al, tantalum responds quite differently to cathodic polarization. Mechanisms of coating formation have been illustrated: Protons and other cations are attracted by cathodic electric field into the coatings, where they undergo a series of reactions to significantly affect the PEO behaviors.

IMPROVEMENT OF HIGH PLASTICITY CLAY BY USING FILTER SLUDGE

Filter sludge (FS) is a waste material that occurs during sugar production in the sugar industry, and since it is not used anywhere, it creates a problem due to storage costs and environmental damage. In the present study, high plasticity clay was stabilized with a filter sludge which has never been used for soil stabilization in field cases. The changes in the geotechnical properties of a high plasticity clay (CH) with the additive of filter sludge (FS) were investigated. The amount of FS mixed into CH soil is 3-6-9-12-15% by dry weight of the soil. Changes in geotechnical properties such as consistency limits, compaction parameters, strength, swelling potential, CBR value of improved soils were determined. The plastic limit and optimum water content increase as the FS content added to the soil increases; liquid limit, plasticity index, and maximum dry density decrease. Improved soil strength increases as the curing time and FS amount increase, and the highest strength was obtained with 15% of FS. At the optimum additive ratio, the unconfined compressive strength increases by 33%. The swelling percentage of CH clay decreases from 42.5% to 20%. According to the wet CBR test results, the bearing capacity of the improved soil increased from %1.1 to %4.4. As a result of this study, it was seen that the FS waste material improved the geotechnical properties of the soil.

Fabrication of functional zirconia surfaces using a two‐beam interference setup employing a picosecond laser system with 532‐nm wavelength: Morphology, microstructure, and wettability

AbstractThe aim of this work was to evaluate the feasibility of the fabrication of microtextures in zirconia using the direct laser interference patterning (DLIP) technique. A green ultra‐short pulsed laser (532 nm, 10 ps) with a two‐beam interference setup was used to produce line‐like structures with a spatial period of 3 µm. For a fixed set of fluence and pulse‐to‐pulse overlap values (6.2 J/cm2, 81%), periodic structures were successfully created for different hatch distances. The average depth of the features ranged from 0.37 µm for a hatch distance of 14.4 µm up to 0.84 µm for a hatch distance of 12.4 µm. However, a further decrease in hatch distance did not result in an increase in depth since the region of the ridges is also ablated. Scanning electron microscopy analysis showed pores formation on the laser grooves, but no sign of micro‐cracking could be observed. Wettability tests showed an increase in hydrophobicity after DLIP. These results bring exciting perspectives on the fabrication of micro‐textures with DLIP on zirconia surface.

Investigating the effect of using recycled waste concrete powder (RWCP) on the performance of thin layer surface treatment: Microsurfacing

Considering the importance of roads and highways in creating communication between different areas, and the issue of repair, maintenance and management of roads has always been among the main concerns of the countries. Microsurfacing is among the best methods for the preventive maintenance of roads. On the other hand, in the present age, production of considerable amounts of construction waste (CW) has turned into a major environmental issue. Thus, the use of recyclable CW in pavements could help with the preservation of non-renewable materials and at the same time reduce environmental problems. The present research attempts to implement recycled waste concrete powder (RWCP) in the mix design of thin layer surface treatment (microsurfacing) to evaluate its performance. In this respect, first the chemical and physical characteristics of the used materials in asphalt were investigated. Next, for evaluating the microsurfacing mixtures use was made of five different microsurfacing mixtures containing 0, 25, 50, 75, and 100% RWCP filler. Assessment of RWCP containing microsurfacing mixtures was done by performing the wet cohesion test, wet track abrasion test (WTAT), loaded wheel-sand adhesion test, and loaded wheel-displacement test according to ISSA A143 Guideline. Then using the FTIR, XRF, and FESEM-EDS tests, the structure, chemical bond, and functional groups, constituting components, and shape and surface of the grains were investigated, respectively. The results revealed that RWCP due to containing large amounts of CaO and SiO2, also having a rough surface compared to that of the natural filler could improve the microsurfacing performance. For example per 9% bitumen, the mixture containing 75% RWCP causes an increase of cohesion at 30 and 60 min durations by 23.4 and 22.7%, respectively. Also, it improves resistance against abrasion by 45%, reduction of mixture bleeding by 18%, and increases resistance against vertical and lateral displacements by 20 and 16%. In addition, considering the analysis of variance (ANOVA) results, all the three factors i.e. bitumen, RWCP filler, and interaction of materials were effective on the microsurfacing performance.

Airport pavement performance evaluation of pavement fog seal based on optimized test technology

Fog seal technology is widely used in airport asphalt pavement. The research on the performance and application of fog seal material is basically at the level of modified emulsified asphalt. The fog seal test method in the existing specification has defects. Three kinds of fog seal materials with different substrates were selected in this paper. Based on the characteristics of fog seal treatment and the relevant specifications of fog seal and airport pavement. Wet Track Abrasion Test (WTAT), Cantabro test, Water seepage test, and Pendulum instrument tester pavement friction coefficient test were improved. Test the pavement performance of different types of fog seals. The results show that the mass loss of material C was less than 10% after 200 and 400 cycles of wear. The improvement effect of material C on raveling resistance and impermeability was far better than that of materials A and B. The improvement of material C on the raveling resistance of the mixture could reach 50%. The immediate improvement effect on the impermeability was nearly 100%. The skid resistance performance of the three fog seal materials decreased after treatment. The decrease in material C was more significant than in materials A and B. In constructing material C, the dose of emery should be appropriately increased. It was advisable to not be less than 0.35 kg/m2. The fog seal layer improves pavement performance. It has reference significance for using fog seal technology to treat early airport pavement diseases.

A micromodel investigation on the flooding of glycolipid biosurfactants for enhanced oil recovery

Biosurfactants can enhance oil recovery by decreasing the interfacial tension between water and oil, and altering the rock's wettability. In this study, the effect of two low molecular-weight glycolipid biosurfactants (rhamnolipid and sophorolipid) on enhancing oil recovery was investigated. The biosurfactants were economically produced from waste sunflower oil. The qualitative oil dispersion experiments were used to evaluate the biosurfactants’ ability to separate oil, Surface tension and interfacial tension tests were carried out at various salinity rates. The potential of rhamnolipid and sophorolipid solutions to alter carbonate rock from an oil-wet state to a water-wet state was studied using the wettability test by measuring the contact angle. Moreover, the effect of rhamnolipid and sophorolipid biosurfactants on breaking the emulsion and improving the sweeping efficiency in porous media was investigated and compared using the micromodel test. Then three distinct homogeneous, heterogeneous, and layered patterns were created and tested in order to completely investigate the difference in oil displacement mechanism in three micromodels, and the impacts of the biosurfactant injection zone's permeability on oil recovery to design injection well patterns. The test results showed that these two biosurfactants were effective at separating crude oil from water. It was further observed that the rhamnolipid solution at 1000 ppm concentration and 60,000 ppm salinity reduced the interfacial tension to 5.42 mN/m, and the sophorolipid solution at 5000 ppm concentration and 80,000 ppm salinity reduced it to 7.93 mN/m. The rhamnolipid solution increased the contact angle between the oil drop and the carbonate rock from 41.42° to 109.26°, and the sophorolipid solution increased it from 32.16° to 104.12°. Also, the micromodel flooding test confirmed that in the case of rhamnolipid solution at the optimal concentration and salinity, the amount of oil recovery was measured as 80, 70, and 74% in the homogeneous, heterogeneous, and layered micromodels, respectively, while for the sophorolipid solution at the optimal concentration and salinity, it was recorded as 71, 61, and 69%, respectively. The micromodel results did not prove the fingering phenomenon under injection of either rhamnolipid or sophorolipid. Furthermore, proper distribution and breaking of the emulsion into micron size were confirmed. Accordingly, one can conclude that both surfactants (rhamnolipid and sophorolipid) have the potential to be utilized in oil field operations.

Gluing Characteristics of Giant Bamboo Using Four Commercial Adhesives

The study aimed to determine the bonding performance of laminated giant bamboo[Dendrocalamus asper (Schult.) Backer] glued with four commercial adhesives (PVAc-D3, PUR, UF, PF) at different surface pairings (pith-pith, pith-skin, and skin-skin) and glue spread rates(100, 150, and 200 g/m2). Kiln-dried giant bamboo poles were ripsawn, planed, and cut to length to produce slats for lamination. Slats for surface roughness and wettability tests were sanded with 180-grit sandpaper on both skin and pith surfaces. Surface roughness of the skin and pith was measured using Mitutoyo SJ–210 Surftest unit, whereas wettability was determined via the sessile drop method. Giant bamboo slats were bonded using specific lamination parameters for each adhesive. Tensile shear tests at dry and wet conditions were performed on the laminates to determine bond strength. The results showed that the bamboo pith had a rougher texture than the skin but with insignificant contact angle differences. Moreover, PVAc-D3 and PUR gave the highest and lowest initial contact angles on both sides, respectively, with PUR maintaining the smallest values throughout the contact duration. Adhesive, surface pairing, and some interactions (adhesive x glue spread and adhesive x surface pairing) significantly affected the dry shear strength, whereas adhesive and adhesive x surface pairing influenced wet shear strength. PUR-bonded laminates had the highest dry shear strength, followed by PF, PVAc-D3, and UF. In terms of wet shear strength, only PVAc-D3 did not conform to the minimum glue bond strength requirement of more than 1 MPa and cohesive bamboo failure of at least 40% (PNS 2099:2015). Skin-skin and pith-pith surface pairing yielded the highest and lowest dry shear strengths, respectively. Increasing the amount of glue did not translate to a stronger bond. PUR, UF, and PF are feasible alternatives to PVAc-D3 in engineered bamboo production for various end-uses.

Experimental Study on Strength and Dry–Wet Cycle Characteristics of South China Coastal Soft Soil Solidified by Cement Collaborating Sand Particles

To study the influence of sand particles on the strength and dry–wet cycle characteristics of cement-solidified South China coastal soft clay, a series of cement-solidified South China coastal soft clay samples with different contents and sizes of sand particles were prepared, and unconfined compression strength (UCS) tests, dry–wet cycle tests under seawater and freshwater conditions, scanning electron microscopy tests, and X-ray diffraction tests were carried out. The test results show that the UCS of cement–sand-solidified soil (CS-SS) samples at 7, 14 and 28 d increase as sand particle content increases, and their 28 d strength increase as sand particle size decreases; the average mass loss rate of sand–cement samples ranges from 14% to 61%. The properties of strength and dry–wet cycle durability improve as the sand particle content increases and the sand particle size decreases. Moreover, the anti-dry–wet cycle ability of samples under freshwater conditions is better than those under seawater conditions. The scanning electron microscopy (SEM), X-ray diffraction (XRD), and ion chromatography test results show that the stiffness replacement effect (the high stiffness of sand particles replaces the low stiffness of soft clay), the interface cementation effect between the sand particles and cemented soil, and the microcrack expansion-obstructing effects of sand particles contribute to the improvement of the strength and dry–wet cycle durability of cement–sand solidified South China coastal soft clay.

Study and Investigation of Microbial Influenced Corrosion Effect for Performance Analysis of Vortex Tube on Stainless Steel with and without Coating

Alloy material testing for stable the properties of Vortex tube and corrosion resistance, this research for specially for fabrication of Vortex tube and also in future may supplier will ask the properties and testing evidence we are going to provide week wise testing schedule. Microbial Influenced Corrosion (MIC) is a type of corrosion that happened on a metal's surface under the seawater. MIC occurs due to the colonization of microorganism on the surface, these microorganisms may be fungus, bacteria or algae. In this paper the E. Coli bacteria are used to investigate the MIC on metal sample of vortex chamber. A metal sample of vortex tube which is stainless steel is coated with different coating such as alocit, rubber, epoxy, and graphene. The samples for vortex tube with different coating are tested to find out the best one which can resist MIC better than the others. There are different tests carried out; wet and dry test, atmospheric test. To find the corrosion progress the weight loss and corrosion rate is found in the sample material to apply vortex tube. The hardness of the coating is done to find the best one. The optical microscope is used to understand the corrosion progress in the metal surfaces and for the hardness test. The result analyzed shows that graphene is the best coating because of its excellent properties in resisting and preventing MIC corrosion of vortex tube is a non-conventional cooling device, having no moving parts which will produce cold air and hot air from the source of compressed air without effecting the environment when a high-pressure air is tangentially injected into the vortex chamber, a strong vortex flow will be created which will be split into two air streams. Beyond that, the improvement in energy separation is minor, and Vortex Tube performance begins to deteriorate as shock waves form outside the nozzle. Without any moving parts or chemical reactions, a vortex tube (VT) can generate hot and cold streams from a single pressurised room temperature fluid.

Strategi Kepala Madrasah Dalam Peningkatan Budaya Bersih Di MA Ar-Rahman Sumoyono Diwek Jombang

This study aims to describe the strategies of the headmaster of madrasas in improving clean culture and what the supporting and inhibiting factors are in improving clean culture at MA Ar-Rahman Sumoyono, Diwek, and Jombang This research method is qualitative field research. This study uses a qualitative descriptive research design. Data collection techniques include structured interviews, participatory observation, and documentation. Then the data wettability test was carried out by extending observations, triangulation, and peer discussions. Followed by data analysis, namely data reduction, data display, and conclusion drawing or verification. The results showed that increasing the culture of cleanliness by implementing the Clean Saturday program has gone quite well by observing the active participation of madrasa residents, providing motivation to build awareness in maintaining cleanliness, and being supported by adequate cleaning tools. The inhibiting factors in this program are the different levels of student understanding of directions and student awareness in caring for cleaning tools, which are still lacking.

Atmospheric pressure plasma jet for surface texturing of C/SiC

C/SiC composites are materials to be used in harsh environments overcoming the limits imposed by the intrinsic brittleness of their ceramic constituents while providing both high mechanical performances at high-temperature temperatures and low weight. In order to manufacture the final component, joining C/SiC, to itself or to other materials, is often necessary, and it is critical to maximize the strength of the joints (similar or dissimilar) in order to meet reliability criteria.In the present work, a pre-joining treatment based on an atmospheric pressure plasma jet (APPJ) was proposed to introduce a brush-like texture on the surface via the selective removal of carbon fibers. The investigation of treated surfaces via electron microscopy and confocal 3D-profilometry confirmed that the treatment was effective in introducing a brush-like texture and in increasing the available contact area. Wettability test and inspection of cross-section of CB4 wetted samples were then carried out. The latter confirmed the formation of anchoring points given by the brush-like texture. Finally, the effectiveness of the treatment in improving the joint strength was assessed by comparing the apparent shear strength of CB4 brazed composites, with and without the APPJ pre-treatment. The joints with plasma pre-treated C/SiC showed a shear strength of about 66 MPa, 44% more than the strength of joints produced with untreated C/SiC.

Carbon fiber: Characterization and evaluation of the inflammatory response and toxicity in rats.

This study aimed to evaluate the Carbon Fiber obtained from PAN textile and cotton fiber in their different forms of presentation: non-activated carbon fiber felt (NACFF), activated carbon fiber felt (ACFF), silver activated carbon fiber felt (Ag-ACFF), and activated carbon fiber tissue (ACFT), to obtain scaffolds as a potential material with properties related to the synthetic bone graft. Characterization tests performed: surface wettability, traction, swelling, and in vivo tests: evaluation of the inflammatory response by implanting the materials in the subcutaneous tissue of 14 Wistar rats, evaluation of collagen fibers by picrosirius red staining and assessment of toxicity in the following organs: heart, spleen, liver, and kidney. In the wettability test, NACFF and ACFT were hydrophobic (θ124° and 114°), ACFF and Ag-ACFF were hydrophilic. For maximum stress, ACFF was more resistant (2.983 ± 1.059) p < .05. In the swelling test, the Ag-ACFF and ACFF groups showed the highest absorption percentage for the PBS solution and distilled water (p < .001). The organs showed no signs of acute systemic toxicity. The implant regions showed mild to moderate inflammatory infiltrate at 7 and 21 days. Only the ACFT group did not show the maturation of type I collagen fibers in 21 days. Through the conducted analyses, the ACFT shows little potential to be indicated as a possible scaffold. Therefore NACFF, ACFF, and Ag-ACFF have the potential to be considered scaffolds due to the following characteristics presented: good absorption rate, hydrophilicity, and non-toxic.

Effect of radiation sterilization on the ability to induce adipose regeneration in vivo in decellularized adipose-derived matrix.

Decellularized adipose-derived matrix (DAM), a biological scaffold that can induce adipose regeneration. The balance between its sterilization efficiency and its ability to maintain in situ adipose regeneration should be considered in terminal sterilization. The purpose of this study was to investigate the effects of radiation sterilization of cobalt-60 (60 Co)with different doses on adipogenesis induced by different forms of DAM, so as to reduce radiation dose under the premise of safe and effective sterilization and ensure adipogenesis induced by DAM in vivo. High dose (25kGy) and low dose (5kGy) radiation were used to sterilize freeze-dried and wet DAM, respectively. The sterilization efficiency, macro and micro characteristics, mechanical and mechanical properties of DAM were compared, and then implanted into the immunocompromised mice to evaluate the adipose regeneration. Under the two radiation doses, no microbial growth was found in the freeze-dried and wet DAM sterility tests, and no significant changes were observed in the macro and micro structures. In terms of mechanical properties, the elastic modulus of high dose freeze-dried DAM decreased significantly (p<0.001). In vivo animal experiments, the freeze-dried DAM irradiated with high dose almost completely lost its function of adipogenesis in vivo. Although the wet DAM irradiated with high dose could induce fat regeneration in the early stage, the adipocyte deformation and atrophy appeared in the later stage. The freeze-dried and wet DAM after low dose irradiation was similar to the wet DAM without irradiation in the blank control, which could maintain excellent adipogenic and angiogenic functions in vivo. High dose 60 Co irradiation can completely destroy the ability of freeze-dried DAM to induce adipose regeneration in situ, while low dose irradiation (5kGy) can effectively sterilize the DAM without damaging in vivo induced adipose regeneration. Radiation has more damage to freeze-dried DAM than wet DAM in adipogenesis properties.

The effect of addition of K2ZrF6 on the structures and properties of AZ31 magnesium alloy MAO coating

It is a challenge to improve the corrosion rate and blood compatibility of biomedical magnesium alloy implants in human body. Scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD) were used to study the Properties of K2ZrF6 modified AZ31 magnesium alloy composite coating. The corrosion behavior of the sample in simulated body fluid (SBF) was evaluated by hydrogen evolution corrosion, potentiodynamic polarization cur ve and electrochemical impedance spectroscopy. The results show that the corrosion resistance of magnesium alloy is significantly improved by composite coating. The wettability test shows that K2ZrF6 greatly improves the biocompatibility of MAO coating on magnesium alloy. The hemolysis test shows that the composite coating makes magnesium alloy have low hemolysis rate. The increase of PH value and magnesium ion concentration in solution caused by corrosion of magnesium alloy can be adjusted by adding K2ZrF6. The corrosion resistance mechanism of MAO coating on K2ZrF6 modified magnesium alloy was discussed. In this experiment, the optimum amount of K2ZrF6 is 4 g/L.

Experimental and molecular dynamics simulation study of the ionic liquids’ chain-length on wetting of bituminous coal

Controlling coal dust pollution is confronted with numerous challenges in the demanding environment of deep mining. Chemical additives, imidazolium ionic liquids (ILs), have been considered an effective strategy to boost the hydrophilicity of coal and reduce dust emissions. This work conducted experiments with molecular dynamics (MD) simulation to study the wetting characteristics of ILs ([Emim][Cl], [Bmim][Cl], and [Hmim][Cl]) with different chain-length on coal. The static wettability tests results indicated that the wettability of ILs was improved as the chain-length increased, and the wettability on bituminous coal followed the rule of water<[Emim][Cl]<[Bmim][Cl]<[Hmim][Cl]. The dynamic dust suppression experiments in the roadway showed that the dust suppression efficiency of 2% [Hmim][Cl] reached 77.5%, 2.45 times that of water. The ESP and frontier orbital energy show that the chain-length increase can enhance the ILs activity. The MD results indicated that short-chain ionic liquid ([Emim][Cl]) tends to accumulate on the surface of coal molecules, whereas long-chain ionic liquid ([Hmim][Cl]) possesses the capability to permeate coal molecules and serves as a tunneling role between coal and water, thereby enhancing the hydrophilicity of bituminous coal. The research results could be used to determine and design ILs with excellent wetting performance for improving the coal dust suppression effect.

CARBONATION PERFORMANCE OF KAOLIN TREATED WITH GROUND GRANULATED BLAST FURNACE SLAG

This study is prompted by the fact that currently available information, regarding carbon dioxide (CO2) and ground improvement, is rather limited, as the emphasis in this area, is mainly directed at health and environmental issues. This includes efforts to counter climate change, by reducing the level of carbon dioxide levels in the atmosphere. Nonetheless, several geotechnical researchers have delved into CO2 sequestration, through magnesium-rich materials. Among such materials is ground granulated blast furnace slag (GGBS). This waste material, which contains between 5% to 9% magnesium, and roughly 35% calcium, appears to be a favourable option for CO2 sequestration. The purpose of this study, is to determine the appropriate optimal amount of GGBS (based on the strength value recommended by the Public Works Department), and its effect in terms of durability, for the treatment of kaolin clay, under ambient and carbonated conditions, with a 24-hour carbonation period, subjected to a CO2 pressure of 200 kPa. Compaction, unconfined compressive strength (UCS), and durability (wetting and drying) tests were performed, with various GGBS contents (5%, 15% and 25%), and curing periods (7, 14, 28 and 60 days). The test results indicate an increase in strength of almost 20 times, for kaolin clay treated with 25% GGBS, with a curing period of 60 days (ambient condition). An additional 22.86% increase in strength was registered, for carbonated conditions. The wetting and drying test, also demonstrated that GGBS-treated kaolin was improved in terms of durability, while retaining its strength under wet and dry conditions. Thus, it can be concluded that with an appropriate amount and curing period, GGBS has the potential to stabilize kaolin clay, and contribute towards the realisation of a more sustainable environment, by curbing the amount of CO2 released into the atmosphere.