Etching Research Articles

The applicability of high-frequency ultrasonic testing for the inspection of the bonded interface between a divertor's mono-block and screw pipe

This study investigated the applicability of high-frequency ultrasonic testing to inspect the tungsten-copper bonded interface between a divertor's mono-block and a cooling pipe called the “screw pipe.” Mock-up samples simulating the interface were fabricated by diffusion bonding of a 2.5 mm thick oxygen-free copper plate to a 12 mm thick tungsten block that satisfied the ITER material specifications. After making the bond, grooves were machined on the oxygen-free copper side of the samples. High-frequency ultrasonic tests were performed before and after machining the grooves using an ultrasonic scanner with a 30 MHz probe in the immersion pulse-echo setting. The testing results showed that the original screw pipe has a low capability for inspection with high-frequency ultrasonic testing. The visibility of a defect at the interface decreased because of the reflection of ultrasonic waves from the slope of the grooves and interference by the echoes from the interface and the grooves’ surfaces. These issues were addressed by proposing geometrical modifications for the grooves and testing with high-frequency ultrasonic testing. The proposed modifications considerably increased the visibility of a defect at the interface and improved detectability by high-frequency ultrasonic tests.

Coal gasification fine slag derived porous carbon-silicon composite as an ultra-high capacity adsorbent for Rhodamine B removal

The extensive release of industrial solid wastes and organic dyes has led to severe environmental pollution, underscoring the urgent need to recycle these solid wastes and to remove the dyes. Herein, a porous carbon-silicon composite (PC-SiO2) is synthesized using coal gasification fine slag (CGFS) as a precursor via an alkali (KOH) activation and an acid (HCl) etching process, and used as an adsorbent for the Rhodamine B (RhB) removal. The as-synthesized PC-SiO2 possesses an ultra-high specific surface area of 1275.63 m2/g, a large pore volume of 0.26 cm3/g, and enriched reactive functional groups (e.g., Si-OH and –COOH). Due to these features, the actual adsorption capacity and removal ratio of the PC-SiO2 for RhB were as high as 1383.72 mg/g and 92.25 %, respectively, at 298.15 K and pH = 7. Further studies indicate that the adsorption of RhB on PC-SiO2 fits both the pseudo-second-order kinetic model and the Langmuir model, with the maximum equilibrium adsorption capacity being 1388.89 mg/g as predicted by the Langmuir model. The adsorption process involves the electrostatic attraction, hydrogen bonding, π-π interaction, and pore-filling mechanism. This work not only offers a novel approach for removing organic dyes from industrial wastewater but also provides an effective strategy for producing high-value-added materials from industrial solid wastes.

In-situ growth transformation and oxygen vacancy synergistic modulation of the electronic structure of NiCo-LDH enables high-performance hybrid supercapacitors

This article successfully constructs NiCo-LDH nano cages formed by in-situ triggering (IS-LDH), and synergistically modulates the electronic structure by introducing oxygen vacancies. The in-situ triggered generation of NiCo-LDH (IS-LDH) by synthesizing ZIF-67 owns a typical rhombic dodecahedral structure and sensitivity to acid etching. Characterization analysis revealed that the IS-LDH nanocage succeeded the polyhedral structure morphology of ZIF-67 but with multiple vertically aligned nanosheets on the shell. Oxygen vacancies (Ov) were introduced into the IS-LDH through a chemical reduction process using sodium borohydride. The findings demonstrate that the synthesized OvIS-LDH nanocapacitor has a low charge transfer resistance (Rct) with a specific capacitance as high as 1111C g−1 (at 1 A g−1). After 10,000 cycles of charge-discharge measurements, the capacity retention rate was 89.45%. Density functional theory (DFT) calculations confirmed that the inclusion of Ov enhanced the repulsion of OH− by the LDH nanosheets and improved the intrinsic conductivity of LDH. The assembled hybrid supercapacitor (OvIS-LDH//AC) successfully powered an LED light for 20 min. This study proposes a logical approach for developing anode materials that can enhance the performance of supercapacitors.

Synthesis of multifunctional Ti/RuO2-ZnO composite catalytic electrodes for electrochemical oxidation and hydrogen production from toluene-containing wastewater

Developing electrodes that effectively perform indirect oxidation on nondecomposable organic compounds is a key objective in electrochemical oxidation research. This study focuses on fabricating a Ti/RuO2-ZnO electrode through a simple pyrolysis method on a Ti substrate etched with hydrochloric acid. Hydrochloric acid etching played a pivotal role in enhancing coating stability by markedly increasing the Ti substrate's surface area and hydrophilicity. Analyzing the linear sweep voltammetry revealed that the electrode exhibited a low overvoltage of the oxygen evolution reaction, reaching 221 mV at 10 mA cm−2, indicating effective use as an active anode. The electrode's performance was evaluated by removing toluene contained in a 0.1 M NaCl solution at pH 5. The electrochemical reaction generated active chlorine in the solution, oxidizing 98.66 % of toluene over 3 h and concurrently producing 25.62 mL of hydrogen. This study presents a simple and effective synthesis of a RuO2-based active anode, demonstrating its potential application not only in removing toluene from wastewater but also in hydrogen production.

Reduction of surface treatment time by combination of citric acid and ascorbic acid while restoring shear bond strength of metal brackets bonded to bleached enamel: a pilot study

BackgroundTo investigate the effect of a 50% ascorbic acid with 50% citric acid solution on the immediate shear bond strength (SBS) of metallic brackets after tooth bleaching. The enamel etching pattern and the required quantity of these combined acids as antioxidants following 35% hydrogen peroxide (HP) bleaching were also determined.MethodsThe stability of the solution at room temperature was assessed at various time intervals. Fifty teeth were randomly divided into five groups: non-bleached (G1), bleached then acid etched (G2), bleached followed by a 10-minute treatment with 10% sodium ascorbate and acid etched (G3), 5-minute treatment with 50% ascorbic acid (G4), and 5-minute treatment with a combination of 50% ascorbic acid and 50% citric acid (G5). Groups G2, G3, G4 and G5 were bleached by 35% HP gel for a total of 32 min. Acid etching in groups G1, G2, and G3 was performed using 37% phosphoric acid (Ormco®, Orange, CA, USA) for 15 s. In all groups, metal brackets were immediately bonded using Transbond™ XT primer and Transbond™ PLUS adhesive, with light curing for 40 s. The SBS was tested with a universal testing machine, and statistical analysis was conducted using one-way ANOVA followed by Tukey’s HSD test. The level of significance was set at p < 0.05 for all statistical tests.ResultsStability tests demonstrated that the combined acids remained effective for up to 21 days. Group G5 significantly increased the SBS of bleached teeth to the level of G1 (p < 0.05), while G3 did not achieve the same increase in SBS (p > 0.05). SEM analysis revealed enamel etching patterns similar to those of both control groups (G1 and G2). Kinetic studies at 6 min indicated that the antioxidation in G5 reacted 0.2 mmole lower than in G3 and G4.Conclusion5-minute application of the combined acids enhanced the SBS of bleached teeth comparable to unbleached teeth. The combined acids remain stable over two weeks, presenting a time-efficient, single-step solution for antioxidant application and enamel etching in orthodontic bracket bonding.

Identifying Editions of the Ptolemy of Rome Maps (1478/90–1507/08) by Copper Plates Changes

Traditionally, it has been considered that the Ptolemaic or classical maps from the four editions of Ptolemy’s Geography published in Rome (1478, 1490, 1507, and 1508) are apparently indistinguishable at first glance because they have been printed from the same plates. This poses a problem for antiquarians, collectors, and curators who wish to accurately date their copies. Recently, two very comprehensive articles have been published on the different paper watermarks associated with each edition, which would allow for the correct identification of each one. However, there are occasions when the maps do not display watermarks. This article aims to provide some keys to distinguish between the incunabula editions (1478, 1490) and those of 1507–1508 in cases of the absence of watermarks. In this process of detecting differences, we have used digitized images of the maps. The results show small modifications in the copper plates made between the editions of 1490 and 1507/08. Our findings reveal that seven previously unknown reworked maps have been identified.

Phosphorus-Doping Enables the Superior Durability of a Palladium Electrocatalyst towards Alkaline Oxygen Reduction Reactions.

The sluggish kinetics of oxygen reduction reactions (ORRs) require considerable Pd in the cathode, hindering the widespread of alkaline fuel cells (AFCs). By alloying Pd with transition metals, the oxygen reduction reaction's catalytic properties can be substantially enhanced. Nevertheless, the utilization of Pd-transition metal alloys in fuel cells is significantly constrained by their inadequate long-term durability due to the propensity of transition metals to leach. In this study, a nonmetallic doping strategy was devised and implemented to produce a Pd catalyst doped with P that exhibited exceptional durability towards ORRs. Pd3P0.95 with an average size of 6.41 nm was synthesized by the heat-treatment phosphorization of Pd nanoparticles followed by acid etching. After P-doping, the size of the Pd nanoparticles increased from 5.37 nm to 6.41 nm, and the initial mass activity (MA) of Pd3P0.95/NC reached 0.175 A mgPd-1 at 0.9 V, slightly lower than that of Pd/C. However, after 40,000 cycles of accelerated durability testing, instead of decreasing, the MA of Pd3P0.95/NC increased by 6.3% while the MA loss of Pd/C was 38.3%. The durability was primarily ascribed to the electronic structure effect and the aggregation resistance of the Pd nanoparticles. This research also establishes a foundation for the development of Pd-based ORR catalysts and offers a direction for the future advancement of catalysts designed for practical applications in AFCs.

Research on optimization of engineering parameters of effective action distance of multi-stage alternating injection acid etching

This study calibrated the numerical simulation model by using indoor experiments to measure experimental data related to conductivity, acid rock reaction kinetics and acid fluid loss, and combined it with the numerical simulation model to calculate the multi-condition acid flow under multi-physics coupling . The effective action distance of the acid liquid is finally formed, which can be used at 200℃ and 250℃. The effective action distance of the acid liquid is related to the amount of acid liquid and the number of acid liquid injection stages. A set of quick diagrams that can be quickly applied to multi-stage Alternate injection process design and optimized workflow. After calculation, it is concluded that: for the 200℃ formation, it is recommended that the total amount of acid used in the level 3 injection process should be more than 400m3; if level 2 injection is used, taking into account both cost and benefit, the total acid amount of 300m3 can be close to the same amount of acid in level 3 The effective range of the injection. For the 250℃ formation, it is not recommended to use a solution with small liquid volume and multiple stages. If level 3 injection is used, it is recommended that the acid dosage be more than 500m3; if level 2 injection is used, taking into account both benefits and costs, it is recommended to use 400m3 acid liquid . Injection can obtain an effective distance similar to that of level 3 injection with the same amount of acid.

In-Vitro Study of Osseointegration: Evaluating the Influence of Surface Modifications on Dental Implant Stability.

Osseointegration is critical for the success of dental implants. Surface modifications of dental implants play a crucial role in enhancing osseointegration and implant stability. This in-vitro study aims to evaluate the influence of various surface modifications on dental implant stability. Dental implants with different surface modifications were prepared and subjected to in-vitro testing. Surface modifications included sandblasting, acid etching, and plasma spraying. Implant stability was assessed using resonance frequency analysis (RFA) and pull-out tests. Statistical analysis was performed to compare the stability of implants with different surface modifications. The results showed that implants with sandblasted and acid-etched surfaces exhibited significantly higher stability compared with those with only a machined surface. The mean RFA values for sandblasted and acid-etched implants were 75 ± 5 and 80 ± 6, respectively, whereas machined implants recorded a mean RFA value of 60 ± 4. Similarly, pull-out tests demonstrated higher maximum tensile strengths for sandblasted and acid-etched implants compared with machined implants. Surface modifications, such as sandblasting and acid etching, significantly enhance dental implant stability in vitro. These modifications promote better osseointegration, which is crucial for the long-term success of dental implants in clinical practice.

Toluene oxidation over defected Mn-based catalyst with controlled Mn-O strength derived from LaMnO3 perovskite

Mn-based heterostructure catalysts show great potential for catalytic oxidation of toluene. Here we fabricated a Mn-based catalyst with controlled Mn–O strength from a LaMnO3 perovskite parent, the surficial structure of which was optimized via defect engineering by joint modification of Ce substitution and acid etching. The findings displayed that after introduction of Ce, a Mn3O4/Ce6O11 hybrid was in situ formed inside LaMnO3 structure owing to the incompatibility of Ce atoms, and the etching of acid resulted in the exposure of Mn3O4/Ce6O11 hybrid by exfoliating the surficial structure. The reconstruction of catalyst structure and dismutation of Mn species was conductive to forming more lattice defects and Mn–O–Ce active sites, thereby harmonizing Mn–O strength. Furthermore, the fabricated catalyst exhibited a suitable Mn2+/Mn4+ ratio and more oxygen vacancies, which inferred easy-release of lattice oxygen and improved oxygen adsorption-activation capacity, therefore synergistically contributed to the highest performance (T90 = 259 °C) of toluene oxidation.

Acid-etched fracture morphology and conductivity of acid fracturing in carbonate rock using novel isolation membrane acid

In recent years, low-viscosity isolation membrane acid (ISM acid) has emerged as a novel retardant acid for matrix acidizing and acid-fracturing in carbonate reservoir. Its ability to create long wormholes in carbonate rock has been extensively studied, while its potential to etch hydraulic fracture and generate conductivity has received less attention. To address the knowledge gap, a series of experiments were conducted in this study, including rheological test, acid-etching simulation experiments, surface laser scanning of acid-fractures, and conductivity tests. The differences in rheological characteristics between ISM acid, blank HCl acid, and gelled acid were compared across different lithology along with the morphology and conductivity of the etched fractures. The viscosity of ISM acid is found to be nearly identical to that of blank HCl, which is 1/26th that of gelled acid. However, the acid-rock reaction rate of ISM acid is only 46–55% compared to blank HCl acid. In dolomite formations, the rate approximates that of gelled acid but is lower in limestone formations, indicating a strong ability for low-viscosity retarding. The heterogeneity of ISM acid etching morphology approaches that of blank HCl acid but exhibits greater retard strength than gelled acid. Under medium to high closure pressure (10–30 MPa), ISM acid generates higher conductivity and better retention ability. This study provides certain guidance for the design of ISM acid fracturing in carbonate reservoir.

Improving the non-free radical activated peroxymonosulfate capability of sludge biochar through sacrificial template method: Efficacy and mechanism evaluation

Improving the non-free radical activation ability of persulfate has great significance for the degradation of persistent contaminant in complex water environments. Here, special nitrogen-doped sludge-based catalysts for peroxymonosulfate (PMS) activation were developed through sacrificial template method by employing polymer surfactant (PS) as template agent. The PS usage and acid etching significantly improved the catalyst’s non-radical activation performance for PMS, the contribution of singlet oxygen (1O2) and electron transfer pathway (ETP) to bisphenol A (BPA) removal could be well matched to 72.31 % and 27.69 % in NCF-1/PMS system, respectively. Such non-radical activation characteristic ensures that NCF-1/PMS systems exhibit super oxidation ability of BPA (Kobs = 0.3714 min−1) and strong anti-interference ability to environmental matrixes via simultaneously enhancing both 1O2 and ETP. The critical roles of graphitic N and as-formed Si-O-C sites in activating PMS were revealed through electrochemical analysis, in-situ characterization technology and theoretical calculations. Density functional theory calculations confirmed that the PS addition and desilication process reduced the adsorption energy of the NCF-1 for PMS, and achieved lower energy barrier to cleave the O–H bond of NCF-1/PMS complex, significantly achieving the surge in the major active species of 1O2. This study provides novel regulatory strategies to modulate the non-radical path for persistent pollutant treatment.

Enhancement of titanium surfaces using different acid solutions at room temperature to improve bone cell responses

Background/purposeEarly osseointegration of titanium (Ti) dental implants relies on the surface topography. Surface modification of Ti seeks to enhance bone regeneration around implants. Acid etching is the simple, less technique sensitive and cost-effective technique for surface treatment. The purpose of this study was to elucidate the simplified acid etching technique at room temperature lies in its capacity to enhance both physical properties and biological reactions relevant to bone. Materials and methodsUtilizing sulfuric acid (H2SO4) and hydrochloric acid (HCl), five distinct acid solutions were prepared, and the acid etching process was executed at five different time points at room temperature. The surface characterization of nanoscale modified titanium disks encompassed surface characteristics analysis, wettability and roughness tests. The biocompatibility evaluation involves tests that assess cell attachment, proliferation, alkaline phosphatase activity (ALP), and mineralization. ResultsThe surface modified by HCl exhibited the most significant alterations, characterized by an elevated roughness value and reduced hydrophilicity properties. The surface treated with a mixture of HCl and H2SO4 for 24 h (TH5) displayed a hydrophilic surface and high surface energy. Acid etched surfaces showed the greater cell attachment with long pseudopodia. The cell proliferation rate and ALP reaction rate of TH5 is the highest at day 7. Cells mineralization of Ti surface treated with 37% HCl for 24 h (TC5) shows the lowest and TH5 shows the greatest on day 21. ConclusionThe proposed acid etching at room temperature utilizing a combination of H2SO4 and HCl demonstrated improved physical properties while fostering favorable biological responses.

The Ukãy, Salvadora persica (Salvadoraceae): Historical and literary evidence from stone inscriptions, copper plates, and literature

The Ukãy, Salvadora persica (Salvadoraceae): Historical and literary evidence from stone inscriptions, copper plates, and literature

Experimental study on acid etching mechanism of acid fracturing in carbonate reservoirs

Acid fracturing is one of the most effective methods to enhance oil and gas production in carbonate reservoirs. The effect of acid fracturing is mainly affected by the conductivity, which is controlled by the acid-etched morphology of the fracture face and near-wellbore zone. Currently, the acid etching mechanism of the fracture face and near-wellbore zone is not considered in traditional experiments. The flow and reaction of acid in the fracture are simulated by using the cores with processed artificial fracture and the high-temperature acid-resistant experimental setup based on traditional experiments. The results under different conditions are obtained. The fracture face and inlet end face of cores are analyzed by combining the dissolution rate, reaction rate, average etching depth, and standard deviation. The effects of the lithology, pump rate, thickening agent concentration, and acid concentration on the acid etching mechanism of acid fracturing in carbonate reservoirs are investigated.

Mo-doped La0.4Sr0.6FeO3-δ hollow fiber membrane for air separation and methane conversion

Ceramic oxygen transport hollow fiber La0.4Sr0.6Fe0.95Mo0.05O3-δ (LSFM5) membranes were fabricated via combined phase inversion and sintering technique. High-temperature X-ray diffraction experiments indicated that LSFM5 oxide undergoes second order phase transition at temperature above 300 °C from rhombohedral to cubic structure. The inner and outer surfaces of LSFM5 membranes were modified by acid etching and by depositing a surface decoration layer. For both kinds of membranes with modified surfaces, the enhancement of oxygen fluxes was observed at operating temperature range 860–980 °C, which indicates that the surface oxygen exchange reactions play a decisive role in the control of the oxygen transport. Catalytic experiments of methane partial oxidation (POM) by Ni/LSFM5 based oxygen-permeable membrane reactor exhibited good performance both in the mode with synthetic air on the supply side, and in the mode of POM coupled with CO2 splitting on the supply side.

Corrosion resistance of rapidly formed in-situ steam Mg−Al LDH coating on AM50 Mg alloy pretreated with oxalic acid

The effect of oxalic acid (OA) etching on the formation mechanism and corrosion performance of in-situ steam Mg−Al layered double hydroxide (LDH) coatings on AM50 Mg alloy was investigated by exposing the intermetallic compounds (β-Mg17Al12 and AlMn) on the surface of the alloy. The results demonstrated that the presence of OA led to an increased fraction of intermetallic compounds on the Mg substrate. Mg−Al LDH nucleated and grew around the Al−Mn phase. The best corrosion resistance of LDH coating was obtained with the maximum thickness at a pickling time of 45 s, and the corrosion current density was reduced by three orders of magnitude compared to the substrate. Finally, the formation mechanism of Mg−Al LDH coating on AM50 Mg alloy was proposed.

Assessment of the Micro-Tensile Bond Strength of a Novel Bioactive Dental Restorative Material (Surefil One).

The aim of this study is to assess the micro-tensile bond strength and the mode of failure of a bioactive hybrid self-adhesive composite (Surefil one) under various dentin conditions. Thirty-two extracted human molar teeth were used to test the micro-tensile bond strength of Surefil one under different dentine conditions (no treatment, 37% phosphoric acid etching, and universal adhesive) in comparison with a resin-modified glass ionomer (RIVA). All restorations were light cure-bonded onto flat dentine and then sectioned into beams. Then, fractured specimens were observed under a light microscope to evaluate the mode of failure. The Surefil one no-treatment group (NTG) exhibited the highest micro-tensile bond strength. Furthermore, there was no statistically significant difference observed between the Surefil one adhesive group (EAG) and the Surefil one acid etch group (EG). However, compared to other groups, the resin-modified glass ionomer (RIVA) produced the lowest results, which are statistically significant. Surefil one offers superior bond strength values when compared to resin-modified glass ionomers. Furthermore, Surefil one requires no dentin condition and has more straightforward clinical steps.

Water/ethanol and water/acetone proanthocyanidin solutions enhance the mechanical stability and sealing ability of resin-dentin bonds produced by the cross-linked dry bonding technique

ObjectivesTo evaluate the influence of solvents on the mechanical stability and dentin sealing ability of adhesive interfaces produced on dry dentin after collagen biomodification with a proanthocyanidin-rich grape seed extract (GSE). MethodsFlat dentin surfaces (N = 120) were initially divided into 10 groups. After phosphoric acid etching for 15s, the etched dentin was treated with: water (control), 5 % ethanol, 90 % ethanol, 5 % acetone, 90 % acetone, and the same groups added with 5 % GSE. The treatments were kept on the etched dentin for 60s. Then, the teeth of each treatment were further divided into two groups. Thus, after rinsing, the dentin was kept moist (wet bonding) or air-dried for 60 s (dry bonding). A water-free two-step etch-and-rinse adhesive system (Optibond S, Kerr) was applied, and composite blocks were built up. The teeth were tested for bond strength (μTBS) immediately or after 12 months of aging. Considering the μTBS results, additional teeth were prepared for qualitative analysis of nanoleakage (NL; SEM) and hybrid layer permeability (CLSM). The μTBS data were analyzed with three-way RM ANOVA and Tukey (α = 0.05). ResultsThe immediate μTBS did not differ among treatments for wet dentin. For dry dentin, GSE in 5 % ethanol or acetone presented the highest μTBS values, the latter similar to wet control. After 12 months, μTBS of GSE in 5 % ethanol or acetone were comparable to the immediate results for wet and dry techniques. These reduced NL and improved dentin sealing for both dentin wetness conditions like the immediate wet control. ConclusionsThe application of 5 % GSE to etched dentin, either in 5 % ethanol or 5 % acetone, resulted in enhanced mechanical stability and dentin sealing of interfaces produced on dry dentin. SignificanceDentin biomodification with proanthocyanidin in the presence of ethanol or acetone makes bonding procedures less sensitive by eliminating the need to keep dentin wet and increasing the quality and stability of hybrid layers produced on dry etched dentin.

Inhomogeneous Au2S for Photoacoustic Imaging and Photodynamic Tumor Therapy Based on Different Forms of Energy Dissipation.

Nanomaterials with unique structures and components play a crucial role in nanomedicine. In this study, we discovered that the inhomogeneous Au2S constructed by cation exchange and acid etching could dissipate energy in different forms after absorbing multichromatic light, which could be used to achieve the integrated diagnosis and treatment of tumors, respectively. Folic acid modified Au2S ringed nanoparticles (FA-Au2S RNs) with an assembly-like structure were demonstrated to result in better PA imaging performance and generate more reactive oxygen species (O2·-, ·OH, and 1O2) than folic acid modified Au2S triangular nanoparticles (FA-Au2S TNs). Finite element analyses determined the reason for the high absorbance properties and synergistic enhancement of plasma resonance in the assembly-like structure of Au2S RNs. Both FA-Au2S nanostructures were modified with folic acid and injected into 4T1 tumor-bearing mice via the tail vein. The best PA imaging contrast was obtained under 700 nm laser illumination, and the most effective PDT antitumor activity was achieved under 1064 nm laser illumination. The PA average of the tumor in the FA-Au2S RN group was approximately 2 times higher than that of the FA-Au2S TN group at 24 h of injection. The PA imaging results of intratumorally injected FA-Au2S RNs proved that they were still able to show better PA signal enhancement at 24 h postinjection. Our study demonstrates that FA-Au2S nanomaterials with unique structures and special properties can be reliably produced using strictly controlled chemical synthesis. It further provides a strategy for the construction of highly sensitive PA imaging platforms and efficient PDT antitumor agents that exploit wavelength-dependent energy dissipation mechanisms.