Energy Dispersive Spectrometer Analysis Research Articles

Study on the removal of fulvic acid in water by potassium ferrate-enhanced iron-manganese co-oxide film and its mechanism.

The previous studies have shown that iron-manganese co-oxide film (MeOx) could simultaneously remove ammonium, manganese ion and bisphenol A. In this study, the removal of fulvic acid (FA) was explored by adding potassium ferrate (K2FeO4) to heighten the catalytic activity of MeOx. After adding about 3.0mg/L potassium ferrate, the elimination efficiency of 7.0mg/L FA by the MeOx increased from 20 to 50%. The effects of temperature and ammonium on the elimination of FA were investigated. Higher temperature (above 22°C) and higher ammonium concentration (above 2.0mg/L) caused a decrease in FA removal. Most of FA combined with the ferric hydroxide colloid produced by K2FeO4 in water to form macromolecular groups, and they were subsequently absorbed and covered on the surface of MeOx. Scanning electron microscope showed that more viscous flocs appeared on the surface of MeOx, and the film thickness became thicker. Electron energy-dispersive spectrometer analysis revealed a notable increased in the C-O element ratio and a significant decreased in the Mn-Fe element ratio on the surface of MeOx. From Fourier transform infrared spectroscopy, the content of transition metal carbonyl compounds increased in the surface of MeOx. XPS analysis confirmed that the presence of Fe3O4, FeO, Mn2O3 and Mn3O4 along with functional group substances of FA attached on the surface of MeOx. The removal mechanism of FA was studied.

Enhancing La(III) biosorption and biomineralization with Micromonospora saelicesensis: Involvement of phosphorus and formation of monazite nano-minerals

The release of rare earth elements (REEs) from mining wastes and their applications has significant environmental implications, necessitating the development of effective prevention and reclamation strategies. The mobility of REEs in groundwater due to microorganisms has garnered considerable attention. In this study, a La(III) resistant actinobacterium, Micromonospora saelicesensis KLBMP 9669, was isolated from REE enrichment soil in GuiZhou, China, and evaluated for its ability to adsorb and biomineralize La(III). The findings demonstrated that M. saelicesensis KLBMP 9669 immobilized La(III) through the physical and chemical interactions, with immobilization being influenced by the initial La(III) concentration, biomass, and pH. The adsorption kinetics followed a pseudo-second-order rate model, and the adsorption isotherm conformed to the Langmuir model. La(III) adsorption capacity of this strain was 90 mg/g, and removal rate was 94 %. Scanning electron microscope (SEM) coupled with energy dispersive X-ray spectrometer (EDS) analysis revealed the coexistence of La(III) with C, N, O, and P. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) investigations further indicated that carboxyl, amino, carbonyl, and phosphate groups on the mycelial surface may participate in lanthanum adsorption. Transmission electron microscopy (TEM) revealed that La(III) accumulation throughout the M. saelicesensis KLBMP 9669, with some granular deposits on the mycelial surface. Selected area electron diffraction (SAED) confirmed the presence of LaPO4 crystals on the M. saelicesensis KLBMP 9669 biomass after a prolonged period of La(III) accumulation. This post-sorption nano-crystallization on the M. saelicesensis KLBMP 9669 mycelial surface is expected to play a crucial role in limiting the bioimmobilization of REEs in geological repositories.

Analysis of the materials and processes of hanging sculptures in Guanyin Hall

Changzhi Guanyin Hall, a folk temple from the Ming Dynasty, embodies the essence of the ‘unity of the three religions’ philosophy, centred around Guanyin Bodhisattva. Over 500 sculptures reside within a modest 70 m2 space, encompassing representations from Confucianism, Buddhism and Taoism. Ranging from a towering 2 m to a mere 10 cm, these sculptures depict an array of characters and mythological scenes, bestowing considerable importance upon the painted sculptures of Guanyin Hall. Varying degrees of deterioration have affected these sculptures due to the passage of time and suboptimal preservation conditions, highlighting the imperative need for meticulous restoration efforts. However, the absence of comprehensive analyses pertaining to the production process of Guanyin Hall sculptures has hindered the restoration groundwork. This study focuses on fallen hanging sculptures and debris, encompassing intact sculptures, clay fragments, wooden sticks, plant fibres, wires and pigments. Employing a series of techniques, including X-ray photography, microscopic analysis, mineral analysis (MLA), laser particle size testing, ion chromatography, X-ray fluorescence spectroscopy (XRF), X-ray diffractometer (XRD) and energy dispersive spectrometer (SEM–EDS) analysis, this research characterises the constituent materials used in crafting these artifacts. Instead of a full-body skeleton, the findings reveal that the small hanging sculpture is supported by delicate wires that hold specific areas, such as the arms and the gown hems. The hanging sculptures are made from a single type of clay and are reinforced with either mulberry bast or wheat straw fibres. A Pinaceae wood stick affixes the head to the body, and the sculpture is then suspended on the wall through nails inserted into the feet. The moulded clay undergoes a sequence of carving, drying and polishing and is coated with a white ash layer before receiving intricate painting. Mineral pigments, including cinnabar, red lead, iron red, cerussite, atacamite, brochantite and azurite, adorn the surface of the sculptures, with gold foil embellishing the golden elements. The intricate artisanry and multifaceted material composition of Guanyin Hall’s painted sculptures render them unparalleled artistic treasures, not solely within Shanxi but across the entire nation. Furthermore, this study establishes a dependable foundation for conservation and restoration endeavours.

Study on the performance of basalt fiber geopolymer concrete by freeze-thaw cycle coupled with sulfate erosion

In this research, double-blended materials such as fly ash and slag are used as binders, and basalt fibers (BF) are mixed in varying volume fractions (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%) relative to the volume of concrete. Besides, sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) served as activators. The study investigates the freeze-thaw resistance, microstructure, performance mechanism, and internal freeze-thaw damage distribution of basalt fiber geopolymer concrete (BFGPC) through freeze-thaw cycle tests coupled with sulfate attack, SEM, and energy dispersive spectrometer analyses. The results indicated that BFGPC possesses excellent freeze-thaw resistance, achieving a minimum frost-resisting grade of F200. Increasing the BF content significantly enhances the frost resistance of the concrete. The hydration products of BFGPC include C–(A)–S–H gel, C–S–H gel, and a minor amount of N–A–S–H gel, which contribute to its structural density and homogeneity. The high compressive strength of BFGPC (87.7 MPa) further contributes to its outstanding freeze-thaw durability.

Performance evaluation of waterborne epoxy emulsified asphalt micro-surfacing with microwave-activated waste rubber powder

As a solid renewable resource, waste rubber powder (R) applied in road engineering can help reduce the environmental pressure caused by "black pollution" and improve pavement performance. In this research, waste rubber powder was activated by microwave method, namely as MR. The content of 0%∼ 5% MR was added as a functional filler to the waterborne epoxy emulsified asphalt (WEA) micro-surfacing mixture, thereby obtaining the MRWEA micro-surfacing. Furthermore, pavement performance, durability and noise reduction property were evaluated and compared with those of WEA micro-surfacing adding non-activated R (RWEA micro-surfacing). Results show that the surface activity of MR has been enhanced effectively, and the surface hydrophobicity of MR is better than R through the contact angle test. These findings are also confirmed by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis. Then, MRWEA micro-surfacing has good workability and cohesion due to the surface activity of MR. At the same dosage MR and R, 30 min, 60 min cohesion of MRWEA micro-surfacing mixture is greater than that of RWEA micro-surfacing mixture. Furthermore, MRWEA micro-surfacing with 3% MR has better wear resistance, rutting resistance, water resistance, durability and noise reduction properties than those of RWEA micro-surfacing with 3% R.

Morphological and structural properties of bismuth-nickel ferrite synthesized by a combined sol-gel method

In this paper, Bi x Ni1-x Fe2O4, (x = 0, 0.3, and 0.5), nanoparticles were synthesized by a sol–gel method, and the synthesized samples were calcination at 350 and 650o C for 3 h. The influence of Bi doping on morphological and structural properties was studied. The field emission scanning electron microscopy (FESEM) analysis showed all of the specimens contain a compact order of homogenous nanoparticles with a spherical form and polyhedral particles with an average size ranging from 36.305 nm to 27.554 nm at 350 and 650o C respectively. By studying the energy dispersive spectrometer analysis patterns, the existence of constituent elements, Ni, Bi, Fe, and O, was verified with a proportion very close to the stoichiometry of the chemical formula. The formation of a ferrite phase was confirmed by X-ray diffraction. An increase in the average crystallite and grain size has been observed with an increase in Bi doping. The Fourier Transform Infrared(FT-IR) studies were made in the frequency range 400-4000 cm-1 and observed two strong absorption peaks. The frequency band is found at 555 cm-1 whereas the lower frequency band is at 1338.5 cm-1. It is noticed that the two prominent absorption bands were slightly shifted towards the higher frequency side with the increase of Bi3+ ion concentration.

Anhydrous sol-gel synthesis of TiO2 nanoparticles: Evaluating their impact on protein interactions in biological systems

This study focused on the synthesis of anhydrous sol-gel synthesis of TiO2 nanoparticles using a hydrothermal route. The chemical properties of the synthesized TiO2 nanoparticles were confirmed through Fourier Transform Infrared Spectroscopy (FT-IR) and UV–Vis spectroscopy, highlighting their optical features. Additionally, Energy Dispersive X-ray Spectrometer (EDX) analysis revealed the high purity of the nanomaterial, while the Transmission Electron Microscope (TEM) displayed spherical particles ranging in size from ≥ 80 nm. Furthermore, X-ray diffraction analysis (XRD), Raman and HRTEM analyses indicated that the nanomaterial exhibits an anatase and rutile structure. When, Hen Egg-White Lysozyme (HEWL) incubated with TiO2 led to notable changes: reduced fluorescence indicating protein unfolding, increased light scattering showing protein aggregation, the presence of amyloid fibrils and hydrophobic regions, and reduced enzyme activity. FTIR spectroscopy revealed amyloid structure formation, while Dynamic Light Scattering confirmed the presence of larger protein oligomers. These findings highlight TiO2's adverse impact on HEWL structure and function, emphasizing the need for further research on nanoparticle toxicity in biological systems, particularly in biomedical applications.

Study on fabrication of force transducer based on carbon nano-flake balls

The purpose of this study was to fabricate a force sensor. A novel three-dimensional carbon-based material called a carbon nano-flake ball (CNFB) was used because it exhibits a large surface-area and high electrical conductivity. Moreover, CNFB can be easily fabricated using a one-step process via microwave plasma chemical vapor deposition. In the present study, two different methods, chemical and mechanical exfoliation, were used to fabricate the CNFB thin films. CNFEs were successfully synthesized on the silicon-based composite substrate. The substrate was constructed by the Si, SiO2, and Al2O3, where Al2O3 played the role of the substrate for the force sensor while SiO2 was the interface layer and was removed in the process by hydrogen fluoride (HF) solution to separate Al2O3 from Silicon. The experiments showed that using sol–gel catalyst coating as pretreatment precursor, results in a larger ball-size but lower deposition density of CNFB on Al2O3 substrate. By using mechanical exfoliation by polyimide (PI) tape, the CNFB grown on silicon substrate can be easily exfoliated from the substrate. PI/CNFB was successfully exfoliated from the substrate with a silver-grey color at the bottom of the CNFB which is likely to be silicon carbide (SiC) from the energy dispersive spectrometer analysis. The sheet resistance of PI/CNFB was 18.3 ± 1.0 Ω sq.−1 PI/CNFB exhibits a good force sensing performance with good stability after 10 times of loading-unloading cycles and a good sensitivity of 11.6 Ω g−1.

Corrosion Performance Analysis of Tubing Materials with Different Cr Contents in the CO2 Flooding Injection–Production Environment

In order to clarify the difference in corrosion performance between low Cr-containing (3Cr, 5Cr, and 9Cr) tubing material and carbon steel N80 in the Carbon dioxide (CO2) flooding injection and production environment and the range of adaptation, corrosion tests and analysis were carried out in simulated working conditions. In this paper, the electrochemical potentiodynamic testing technology and the weight loss method were used to comparatively analyze the corrosion performance and variation law of three types of tubing materials with different Cr contents in a simulated CO2 flooding-produced water environment under different partial pressure conditions. Additionally, scanning electron microscopy and Energy Dispersive Spectrometer (EDS) analysis were conducted to examine the surface corrosion morphology characteristics and elemental composition of material films under various conditions. The results indicate that the open circuit potentials of 3Cr, 5Cr, and carbon steel N80 were similar under the same experimental conditions. However, the open circuit potentials of 9Cr were relatively high and there was an obvious passivation zone in anodic polarization. Nevertheless, compared to that of 13Cr, the passivation state was unstable, and pitting corrosion continued to expand once it formed. This demonstrates that the corrosion resistance of the material can be effectively enhanced and a stable passivation state can be achieved in the anodic polarization region when the Cr content of the material reaches at least 13%. The service life of materials can be predicted based on their corrosion rate under high temperature and pressure simulation environments. We found that 9Cr materials exhibited good adaptability while 3Cr and 5Cr materials showed poor adaptability. Therefore, it was not recommended to use 3Cr and 5Cr materials. Therefore, 3Cr, 5Cr, and N80 materials will be used at lower partial pressure levels of CO2 (<0.2 MPa).

The Liquid Fraction of ZA27 Zinc Alloy from TLP Diffusion Bonding Affecting Mechanical Properties and Microstructural Characterizations of SSC-ADC12 Aluminum Alloy

This work investigated liquid fraction in ZA27 zinc alloy interlayered with SSC-ADC12 aluminum alloy workpieces for Transient Liquid Phase (TLP) diffusion bonding. The results clearly indicated that liquid fraction had a necessary influence on TLP diffusion bonding. In other words, the high liquid fraction and bonding time tends to produce excellent bond strength. The maximum bond strength at 27.21 MPa was from 100% liquid fraction and 90 min from bonding time. The hardness increased by approximately 23.36% comparing to SSC-ADC12 aluminum alloy and by 11.18% comparing to the ZA27 zinc alloy. The microstructure was homogeneous in the bond line and formed to MgZn2 and CuZn4 intermetallic compound under Scanning Electron Microscope. According to Energy Dispersive X-Ray Spectrometer analysis, Zn atoms had the ability to move about 4.381 mm from the bond line and the elements' uniform distribution.

Surface Characterization, Mechanical Properties, and Corrosion Behavior of Zn-Ni Alloy Coated Steel Using Electroplating-Hot-Dip Galvanizing

In this study, the processing of zinc-nickel alloys with an electroplated nickel layer as the first layer followed by hot-dip galvanizing on plain carbon steel (St37) is investigated. The effect of the nickel layer and the effect of the immersion time on the alloy layers of the coating obtained by this method are studied. In addition, some properties of the obtained coating, such as the overall thickness, hardness, surface uniformity, coating adhesion strength, and corrosion resistance, were investigated using the optical microscope, scanning electron microscopy, energy dispersive x-ray spectrometer analysis, and potentiostat. The results show that the 16-min immersion time is the optimum galvanizing time at which an alloy with a nickel content of 0.11 wt% is formed and that the overall thickness of the galvanized sheet, especially the alloy layers, decreases compared to the pure zinc sheet. In addition, a more ductile, corrosion-resistant, and smoother surface is obtained.

Oxidation and hot corrosion behaviour of functionally graded yttria stabilized zirconia and lanthanum zirconate thermal barrier coatings

In the present work, NiCoCrAlY + YSZ (Yttria stabilized Zirconia) and NiCoCrAlY + LZ (Lanthanum Zirconate) multilayer functionally graded thermal barrier coatings (FGTBC) were developed on Inconel 738 using the thermal plasma spray method. The gradual increase in the proportion of top coat material with a simultaneous gradual decrease in the proportion of NiCoCrAlY bond coat minimizes the thermal mismatch resulting in the improvement of the life of the coating. Developed coatings were tested for oxidation and hot corrosion study at 900 °C temperature. The hot corrosion of the coated specimen was conducted in an aggressive environment of 90 wt% Na2SO4 + 5 wt% NaCl +5 wt% V2O5 for 240 h with intermediate removal of specimen after 24 h. The specimens were evaluated by Scanning Electron Microscope (SEM), Energy Dispersive Spectrometer (EDS) and X-ray diffraction (XRD) analysis after oxidation and hot corrosion. The study revealed the dominance of vanadium with the presence of YVO4 phase and LaVO4 phase after hot corrosion on the coating surface. The study near the crack and open surface after crack showed that the use of NiCoCrAlY bond coat in combination with YSZ and LZ, will form an oxidation product i.e. Al2O3 layer protecting the surface. The electrochemical study of the functionally graded YSZ and LZ after the hot corrosion test has revealed the better performance of LZ FGTBC over functionally graded YSZ FGTBC.

Study on the evolution process of corrosion behavior under the sulfate reducing bacteria biofilm in shale gas gathering pipelines

Pipeline corrosion induced by sulfate-reducing bacteria (SRB) is particularly severe during the hydraulic fracturing technology in shale gas exploitation. To investigate the evolution of corrosion beneath the SRB biofilms, 49-day corrosion experiments were performed with and without SRB. The weight loss experiment demonstrated that the corrosion in the Blank group was mitigated by the corrosion product film. In contrast, the SRB group exhibited an initial inhibitory phase followed by an exacerbation. Scanning electron microscopy (SEM) revealed stratification in the Blank group, whereas SRB initially formed colonies and extracellular polymeric substances (EPS), eventually the biofilm evolved into a mixed layer with the corrosion product. 3D microscopy showed a relatively flat surface in the Blank group. Conversely, corrosion pits beneath SRB biofilm were circular and could reach a depth of 29.77 μm, significantly greater than in the Blank group. Over time, SRB-induced pits deepened from the edges to the center and widened to approximately 740 μm, accompanied by an increase in quantity. Energy Dispersive Spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) analyses detected the presence of elements P, S, and FeS in the SRB group, serving as important indicators of SRB corrosion. Electrochemical experiments revealed significantly higher corrosion currents in the SRB group. The evolution of SRB corrosion consisted of three phases: initial, intermediate, and starvation phases. During the starvation phase, localized corrosion proved to be the most severe, with a corrosion rate of 1.28 mm/a. Therefore, the study of SRB-induced corrosion should be prioritized to study the localization phenomena.

In-situ synthesis and characterization of calcium phosphate coatings on rapidly solidified zirconia toughened alumina eutectic bioceramics by laser cladding

Rapidly solidified zirconia toughened alumina (ZTA) eutectic bioceramics are promising load-bearing materials that meet the needs for durability and aging resistance for biomedical applications. However, one of the major problems is their poor bioactivity which may lead to aseptic loosening after long-term service. To solve this problem, calcium phosphate (Ca-P) coatings are in-situ synthesized on rapidly solidified ZTA eutectic bioceramics by laser cladding technology with mixed powders of CaHPO4∙ 2H2O and CaCO3 after granulation as precursors. X-ray diffraction results show that Ca-P coatings are mainly composed of Ca0.2Zr0.8O1.8, AlPO4, Ca4P2O9, Ca3(PO4)2 and Ca2P2O7. The amount of calcium phosphates reaches a maximum when using a laser power of 800 W and a scanning rate of 650 mm/min. Cross-sectional morphologies and energy dispersive spectrometer analysis indicate excellent interfacial bonding between the substrate and coating. In vitro tests prove that Ca-P cladded samples can induce apatite with flake-like morphology similar to those on the bioceramic coatings cladded on titatinum alloy precipitation and promote MC3T3-E1 cell proliferation. This work reveals that laser cladding has the potential to improve the biomineralization of solidified ZTA eutectic bioceramics enabling prolonged clinical service life.

Study on the effect of M/P ratio of magnesium phosphate cement coatings on reducing urban heat absorption

Using reflective coatings to enhance the reflective ability of urban underlying surface can effectively reduce building energy consumption and alleviate urban heat island effect. Magnesium phosphate cement (MPC), which consists of high near-infrared reflectivity magnesium oxide (MgO) and phosphate as the main raw materials, is a potential reflective coating. This paper studied the reflection characteristics and mechanisms of MPC with different mass ratios of MgO to phosphate (M/P). The reflectivity test results indicated that the reflectivity of MPC increased with the increase of M/P ratio, with a near-infrared reflectance of 71.74% at an M/P of 10. This was mainly related to its surface chromaticity and micromorphology. In the matter of color characteristic, it was found that the increase of M/P ratio improved the brightness and weakened the performance of other colors, which was conducive to improving the reflective effect. In the matter of micromorphology, scanning electron microscopy and energy dispersive spectrometer (SEM-EDS) analysis confirmed that there were more unreacted MgO particles and less hydration products on the MPC surface with high M/P ratio, which resulted in higher reflectivity and lower bonding strength. Finally, indoor irradiation experiments were conducted to verify the heat reduction effect of MPC coating on asphalt pavement. The results indicated that the surface temperature of the specimen coated with MPC decreased by 15.3 ℃ compared to the control specimen. Therefore, it could be concluded that MPC is a promising reflective coating that can be used to reduce urban heat absorption.

Generation of nanoflowers and nanoneedles on Co-based layered perovskite of IT-SOFC cathode affecting electrical conductivities

In this study, the unusual microstructure and electrical properties of SmBa0.5Sr0.5Co2O5+d (SBSCO) layered perovskite cathodes with dense and porous microstructures were analyzed by changing the applied current.Unique nanostructure shapes were observed when a high current was applied to a cathode with both dense and porous microstructures of the same chemical composition for electrical conductivity measurement. Nanoflower and nanoneedles, which are types of nanoseeds, were discovered. The nanoneedles were found on the entire surface of the SBSCO cathode, whereas nanoflowers were only present on part of the cathode surface.Results from an Energy Dispersive Spectrometer (EDS) analysis revealed that the nanoneedles generated on the SBSCO matrix had a chemical composition of SmBaCo2O5+d (SBCO).The electrical conductivity of the porous cathode with SBCO nanoneedles (nanoneedle cathode) was 238 S/cm at 700 °C under decreasing temperature in an air atmosphere (Air Down) during the experiment. In comparison, the electrical conductivity of the porous cathode without nanoneedles (normal cathode) was 136 S/cm at the same experiment condition (700 °C, Air Down). This indicates that the electrical conductivity of the nanoneedle cathode was significantly higher than that of the normal cathode.

Anti-poisoning performance of flat-tube solid oxide fuel cell in high concentration [formula omitted]S environment

In this work, the anti-poisoning performance of flat-tube solid oxide fuel cells (FT-SOFCs) is investigated in high concentrations of H2S. The degradation rate of the cell is 0.52%/ h, 0.27%/ h and 0.305%/ h at 750 °C, when the concentration of H2S is 161 ppm, 182∼222 ppm and 226 ppm, respectively, and the performance can be restored by humidification of H2. The resistance to sulfur poisoning breaks through the limitation, proving the stability advantage of the flat-tube structure. Through energy dispersive spectrometer (EDS) and Raman spectrum analysis, it is found that the cell performance degradation under high concentration of H2S is mainly caused by the loss of metallic nickel caused by the migration and decomposition of nickel-sulfur compounds, which will reduce the active sites of H2 participating in the anode reaction. This study provides a reference for the application of flat-tube structure cells under high concentrations of H2S.

Tunable luminescence and efficient energy transfer investigation of a borosilicate phosphor KBSi2O6: Bi3+, Eu3+ with hypersensitive thermal quenching

Energy transfer between Bi3+ and Eu3+ has undergone substantial research but Bi3+ and Eu3+ co-doped luminescent materials with high energy transfer efficiency for temperature sensing are rarely investigated until now. Herein, Eu3+ and Bi3+ co-doped KBSi2O6 phosphors were successfully synthesized by solid-state reaction method. The phase purity structure as well as the element distribution were carefully investigated through X-ray diffraction structural refinement and energy dispersive spectrometer analysis. The characteristic luminescence property and luminescence kinetics of KBSi2O6: Bi3+, Eu3+ were investigated. By the large spectra overlap between the emission spectrum of Bi3+ and excitation spectrum of Eu3+, the energy transfer from Bi3+ to Eu3+ can be inferred. The corresponding decrease of the emission intensity and decay time of Bi3+ in KBSi2O6: Bi3+, Eu3+ provided direct evidence for the effective energy transfer from Bi3+ to Eu3+. The interaction and energy transfer mechanism between Bi3+ and Eu3+ ions were also studied. By increasing the Eu3+ concentration in KBSi2O6: Bi3+, Eu3+, the color-tunable emission from blue to red can be realized. KBSi2O6: Bi3+, Eu3+ shows hypersensitive thermal quenching behavior and the maximum absolute sensitivity (Sa) and relative sensitivity (Sr) are determined to be 1.87 %K−1 and 2.895 %K−1, respectively. All of the above results imply that KBSi2O6: Bi3+, Eu3+ phosphor can be a color-tunable phosphor for optical temperature sensing.

Study of Streptococcus mutans in Early Biofilms at the Surfaces of Various Dental Composite Resins.

Biofilm deposit on the composite restoration is a common phenomenon and bacterial growth follows the deposition. The study aims to evaluate Streptococcus mutans (S. mutans) early biofilm formation on the surfaces of various dental composite resins by using the real-time quantitative polymerase chain reaction (qPCR) technique. Thirty-two discs, where eight discs were in each group of Filtek Supreme Ultra (FSU; 3M, St. Paul, MN), Clearfil AP-X (APX; Kuraray Noritake Dental Inc., Tokyo, Japan), Beautifil II (BE2; Shofu, Inc., Kyoto, Japan), and Estelite Sigma Quick (ESQ; Tokuyama Dental, Tokyo, Japan), were fabricated and subjected to S. mutans biofilm formation in an oral biofilm reactor for 12 hours. Contact angles (CA) were measured on the freshly fabricated specimen. The attached biofilms underwent fluorescent microscopy (FM). S. mutans from biofilms were analyzed using a qPCR technique. Surface roughness (Sa) measurements were taken before and after biofilm formation. Scanning electron microscopy (SEM), including energy dispersive X-ray spectrometer (EDS) analysis, was also performed for detecting relative elements on biofilms. The study showed that FSUdemonstrated the lowest CA while APXpresented the highest values. FMrevealed that condensed biofilm clusters were most on FSU. The qPCR results indicated the highest S. mutans DNA copies in the biofilm were on FSU while BE2was the lowest (p < 0.05). Sa test signified that APX was significantly the lowest among all materials while FSU was the highest (p < 0.05). SEM displayed areas with apparently glucan-free S. mutans more on BE2 compared to APX and ESQ, while FSU had the least. Small white particles detected predominantly on the biofilms of BE2 appeared to be Si, Al, and F extruded from the resin. Differences in early biofilm formation onto various composite resins are dependent on the differences in materialcompositions and their surface properties. BE2 showed the lowest quantity of biofilm accumulation compared to other resin composites (APX, ESQ, and FSU). This could be attributed to BE2 proprieties as a giomer and fluoride content.

Impact of magmatic intrusion on diagenesis of shallow marine sandstones: An example from Qasim Formation, Northwest Saudi Arabia

Igneous intrusions are common in sedimentary basins, and their occurrence can significantly affect the diagenesis and reservoir quality evolution of sandstones, thereby strongly impacting their hydrocarbons-, geothermal-, and CO2-storage potentials. The Qasim sandstones in the Tabuk region (NW Saudi Arabia) experienced shallow burial diagenesis (&amp;lt;2 km) when the Tertiary magma intruded to form basaltic sills (0.4–4 m thick). The sedimentology, tectono-stratigraphic framework, provenance, and chemostratigraphy of the Qasim Formation have been extensively covered in the literature. However, the impact of the magmatic intrusion on diagenesis and reservoir quality evolution of the sandstones remains enigmatic. This study employed thin-section petrography, QEMSCAN, XRD, SEM, and energy-dispersive spectrometer analyses to investigate the role of magmatic intrusion on diagenesis and reservoir quality of the Qasim sandstones. The results of the study indicate that reservoir porosity is principally influenced by primary depositional characteristics (grain size and sorting), diagenetic alterations, and magmatic intrusions. Sandstones with coarser grain size and better sorting have the best intergranular porosity and vice versa. The “normal” diagenetic processes that have significantly affected the reservoir porosity of the sandstones occurred during both shallow burial (eodiagenesis) and uplift (telodiagenesis). The eogenetic alterations include mechanical compaction, early diagenetic cementation by calcite, pyrite, and kaolinite, whereas the telogenetic alterations include the formation of kaolinite, goethite, hematite. Overall, mechanical compaction is the main driver for porosity loss in the sandstones. The intrusion-related diagenetic processes include the dissolution of quartz grains, rounded quartz overgrowths, and calcite cement, and the transformation of kaolinite into dickite and chlorite. Detrital quartz and rounded quartz overgrowths have undergone dissolution due to acidic pore fluids from magma and high temperature. The transformation of kaolinite into dickite occurred in a dissolution-recrystallization fashion, and the amounts of kaolinite and dickite increase in fine-grained sediments away from sill contact due to hydrodynamic processes that deposited muscovite (which form kaolinite) in low energy environments. The chloritization of kaolinite was localized, and the magma-induced dissolution of goethite likely supplied the requisite high Fe content. Additionally, the intrusion has resulted in the dissolution of the early calcite and increase in porosity towards the sill contact. However, values for compactional porosity loss have relatively remained similar both at and away from the sill contact, as the sill is too thin to exert significant vertical loading. This study has relevance to understanding hydrocarbon exploration and exploitation in sediment-lava sequences, and to understanding the development of sediment-lava systems.