Sequential Procedure Research Articles

Sequential oxidation procedures with KMnO4: Component characteristics of labile reducing capacity fractions in anaerobic sediments

Reducing substances are a mixture of different forms and types and play extremely important roles in manipulating the redox status of sediments, benthic habitats, and substance exchanges at the sediment-water interface in aquatic ecosystems. However, little is known about their abundance, forms, and reducibility in sediments. In this study, the procedures were developed to sequentially fractionate sediment reducing capacity (RC) fractions with the pH dependence of KMnO4 oxidability. The procedures were then applied to 60 sediments from 2 lakes and 3 reservoirs, generating an RCpH7.0 fraction (oxidized at ~0.48 V [reference: SHE]) and an RCpH2.0 fraction (oxidized at ~0.95 V [reference: SHE]), and the component of each fraction was characterized. The RCpH7.0 fraction amounted to 45.4 ± 25.9 cmol e−·kg−1 DW, and the RCpH2.0 fraction amounted to 42.8 ± 22.9 cmol e−·kg−1 DW; fraction sizes depended greatly on sediment origin. Reducing organic substances (ROS) were the main contributors to the RC fractions, with mean value of 30.0 ± 24.1 and 38.5 ± 22.2 cmol e−·kg−1 DW in RCpH7.0 (% contribution: 68.0 ± 5.3 % of RCpH7.0) and RCpH2.0 (90.0 ± 1.5 % of RCpH2.0), respectively. The next contributor was Fe(II), with mean value of 13.5 ± 8.2 and 3.8 ± 3.7 cmol e−·kg−1 DW in RCpH7.0 (28.3 ± 5.2 %) and in RCpH2.0 (9.9 ± 8.6 %), respectively. The smallest component was sulfide (Sn), which had a mean of 2.0 ± 3.1 cmol e−·kg−1 DW in RCpH7.0 and was essentially negligible in RCpH2.0. The number of electrons lost per mole of reducing substances (Ni) differed between the two RC fractions and among sediments of different origins. NROS was lower in the RCpH7.0 fraction (0.22 ± 0.09) compared to the RCpH2.0 fraction (0.31 ± 0.12) and significantly related to levels of active Fe(III) and sulfides (Sn) (p < 0.05). The opposite pattern was seen for NFe(II) and NSn. Based on the compositive reducing capacity (CRC) for the RCpH7.0 fraction, sediment redox status could be classified as ROS-Fe(II) (3.8 ± 1.7 cmol e−·kg−1 DW) or ROS-Sn (10.1 ± 4.8 cmol e−·kg−1 DW) (weaker vs. stronger, respectively; p < 0.01). The RC-based index provides a more comprehensive perspective on characterizing sediment redox status compared to the Eh.

Cataract surgery with endothelial keratoplasty.

This review aims to provide an updated summary of the combined approach of cataract surgery with endothelial keratoplasty (EK), addressing key considerations, including intraocular lens (IOL) choice and calculation, decision between sequential and triple EK, and modifications in surgical techniques and postoperative management. Advances in imaging techniques (Scheimpflug tomography and anterior segment optical coherence tomography) have improved the ability to detect subclinical corneal edema, aiding in surgical decision-making for EK. Recent studies comparing sequential and triple-EK indicate that both methods yield similar visual outcomes. Though triple-EK offers quicker recovery, it may have higher complication rates. The use of gases like SF6 and C3F8 for anterior chamber tamponade is evolving, with conflicting findings on their efficacy in preventing graft detachment. Furthermore, IOL selection remains crucial, as hyperopic refractive surprises are common, and hydrophilic lenses should be avoided owing to the risk of opacification after EK. The combination of cataract surgery with EK has emerged as an effective treatment for patients with corneal endothelial diseases and cataract. Careful preoperative evaluation, appropriate IOL selection, and advances in surgical techniques contribute to better outcomes, although patient-specific factors must guide the choice between sequential and triple-EK procedures.

Coupling mechanism of trace elements and maceral in medium and high sulphur coal in the Jurassic terrestrial environment of Zhongyuan mine in the Hengshan mining area and adjacent areas

ABSTRACT Considering the urgency of resource utilization and environmental protection, the geochemistry of anomalous trace transition metal elements in coal formed in terrestrial environments has been studied using methods such as inductively coupled plasma atomic emission spectrometry analysis, electron probe micro-area analysis, sequential chemical extraction procedures, and correlation analysis. The results indicate that minerals in the coal samples included pyrite, kaolinite, quartz, dolomite, calcite, and celestite. Furthermore, compared with the average values of coals in China and the upper continental crust, the coal samples were rich in transition metal trace elements such as Ni, Cr, and Sr and were deficient in Be, Cd, Cu, Co, Ga, Mo, Sb, Tl, V, Zn, and Ti. We found that Ni preferentially occurred in the organic matter over minerals, while Cr primarily bonded with sulfide minerals and to a lesser extent with the iron-manganese oxide minerals. Sr had a low correlation with organic matter but adhered to clay minerals and celestite. Ni enrichment in coal samples was the result of terrigenous input, while the Cr enrichment was related to intrusion of magmatic hydrothermal fluids. Sr enrichment was caused by the presence of SO4 2- in the terrigenous debris and the influence of Sr-rich water underground.

On mitigating reactive jamming with dynamic resource allocation in optical IRS and UAV-assisted FSO-based networks

Free space optics (FSO) offers a promising opportunity to enhance next-generation network’s capacity with its unlicensed spectrum and wide bandwidth. However, jamming attacks, coupled with inherent anomalies in the FSO-based channel, threaten the performance of these networks. This is especially problematic for security-sensitive applications that demand a resilient communication infrastructure. To address this issue, optical intelligent reflecting surfaces (IRS) and unmanned aerial vehicles (UAVs) can provide promising solutions. This work introduces an efficient approach for mirror element assignment in UAV-assisted FSO-based networks, aimed at mitigating reactive jamming attacks while satisfying users’ quality-of-service (QoS) requirements. To ensure network reliability, we formulate an optimization problem that enhances overall network performance by simultaneously allocating resources such as mirror elements with awareness of jamming attacks. The formulated optimization problem is a binary linear programming problem, which is generally NP-hard. To address this, we introduce a batch-based sequential fixing linear programming procedure called the Reactive Jamming-Aware Mirror Element Allocation (RJA-MEA) scheme. This scheme optimally assigns mirror elements to satisfy the users’ rate demands. In this paper, the performance of the RJA-MEA scheme is compared with reference schemes such as Reactive Jamming Unaware-Mirror Element Allocation (RJU-MEA), Reactive Jamming-Aware Equal Mirror Element Allocation (RJA-EMEA), and Reactive Jamming Unaware-Equal Mirror Element Allocation (RJU-EMEA) schemes. The simulation results reveal that the proposed RJA-MEA scheme surpasses existing reference schemes, thereby significantly improving the overall network sumrate performance.

Group sequential testing of a treatment effect using a surrogate marker.

The identification of surrogate markers is motivated by their potential to make decisions sooner about a treatment effect. However, few methods have been developed to actually use a surrogate marker to test for a treatment effect in a future study. Most existing methods consider combining surrogate marker and primary outcome information to test for a treatment effect, rely on fully parametric methods where strict parametric assumptions are made about the relationship between the surrogate and the outcome, and/or assume the surrogate marker is measured at only a single time point. Recent work has proposed a nonparametric test for a treatment effect using only surrogate marker information measured at a single time point by borrowing information learned from a prior study where both the surrogate and primary outcome were measured. In this paper, we utilize this nonparametric test and propose group sequential procedures that allow for early stopping of treatment effect testing in a setting where the surrogate marker is measured repeatedly over time. We derive the properties of the correlated surrogate-based nonparametric test statistics at multiple time points and compute stopping boundaries that allow for early stopping for a significant treatment effect, or for futility. We examine the performance of our proposed test using a simulation study and illustrate the method using data from two distinct AIDS clinical trials.

Unleashing the Power of Domino Reactions on Carbohydrates: State of the Art

AbstractThe intricate nature of carbohydrate structures has prompted the scientific community to seek efficient protocols for their manipulation. Lengthy synthetic pathways, often necessary to achieve complex sugar structures, pose challenges not only in terms of time and cost but also regarding environmental sustainability. Consequently, domino transformations serve as valuable tools in streamlining drug discovery processes. Sequential procedures involving fewer steps and minimal isolation/purification steps are particularly appealing to organic chemists in the field of carbohydrate chemistry. This review highlights several examples of domino transformations applied to carbohydrates, aiming to summarize their chemical potential in delivering sugar‐based compounds with significant applications in the generation of new chemical scaffolds for drug discovery and chemical biology.

Stimulus-Stimulus Versus Stimulus-Valence Learning in Evaluative Conditioning: Insights on the Ecological Conditions of Unconditioned Stimulus Revaluation Effects

Previous research into the influence of postconditioning revaluation of unconditioned stimuli (USs) on evaluative conditioning (EC) effects produced inconsistent results. One potential factor determining the sensitivity of EC to US revaluation is whether conditioned stimuli (CSs) get linked to valence (stimulus-valence learning) or the specific USs (stimulus-stimulus learning). The present research tested the ecological conditions of stimulus-valence learning and thereby US revaluation. In a sequential procedure, Experiment 1 paired CSs with either different USs of the same valence (one-to-many pairings) or the same US repeatedly (one-to-one pairings). Although EC effects were equally large, US revaluation effects and memory for CS-US pairings were reduced for one-to-many compared to one-to-one pairings. Experiments 2 and 3 presented one-to-many pairings in a forward versus backward manner but found the two versions of a sequential pairing procedure equally effective in inducing stimulus-valence learning. We present potential learning mechanisms underlying the outcomes and discuss approaches to their investigation.

Bayesian feedback in the framework of ecological sciences

In ecological studies, it is not uncommon to encounter scenarios where the same phenomenon (e.g., species occurrence, species abundance) is observed using two different types of samplers. For example, species data can be collected from scientific sampling with a completely random sample pattern, but also from opportunistic sampling (e.g., whale watching from commercial fishing vessels or bird watching from citizen science), where observers tend to look for particular species in areas where they expect to find them.Species Distribution Models (SDMs) are widely used tools for analysing this type of ecological data. In particular, two models are available for the aforementioned data: a geostatistical model (GM) for data collected where the sampling design is not directly related to the observations, and a preferential model (PM) for data obtained from opportunistic sampling.The integration of information from disparate sources can be addressed through the use of expert elicitation and integrated models. This paper focuses on a sequential Bayesian procedure for linking two models by updating prior distributions. The Bayesian paradigm is implemented together with the integrated nested Laplace approximation (INLA) methodology, which is an effective approach for making inference and predictions in spatial models with high performance and low computational cost. This sequential approach has been evaluated through the simulation of various scenarios and the subsequent comparison of the results from sharing information between models using a variety of criteria. The procedure has also been exemplified on a real dataset.The primary findings indicate that, in general, it is preferable to transfer information from the independent (with a completely random sampling) model to the preferential model rather than in the alternative direction. However, this depends on several factors, including the spatial range and the spatial arrangement of the sampling locations.

Short-Cycle Autoclave Sterilization of Instruments in Same-Day Ophthalmic Surgeries

What Is the Issue? The volume of ophthalmic surgeries is increasingly high, with cataract surgery being 1 of the most performed surgeries in Canada. Infections following ophthalmic surgeries, while rare, can cause severe complications that may lead to irreversible vision loss. Reducing postsurgery infections is a high priority in clinical practice. Running a full wrapped, terminal steam sterilization cycle for ophthalmic instruments in autoclaves may be inefficient for ophthalmic surgeries and may cause unnecessary heavy economic and environmental burdens due to high surgical volumes. Using instruments sterilized on a short cycle between sequential same-day ophthalmic surgeries may help improve efficiency and reduce resources used. These instruments are generally processed using autoclaves (i.e., steam sterilizers); the effectiveness of a shorter-cycle method of sterilization is unclear. What Did We Do? To inform decisions regarding the use of autoclaves for short-cycle sterilization for sequential same-day instrument use in ophthalmic surgery, we sought to identify and summarize evidence comparing this method to full-cycle sterilization of wrapped instruments and identify any relevant recommendations. We searched key resources, including journal citation databases, and conducted a focused internet search for relevant evidence published since 2012. One reviewer screened articles for inclusion based on predefined criteria. What Did We Find? In a laboratory setting to simulate sequential same-day procedures, short-cycle sterilization with interrupted dry time for unwrapped ophthalmic instruments is feasibly as effective as full-cycle sterilization for wrapped instruments using the STATIM autoclave. Similarly, short-cycle sterilization with interrupted dry time for contained ophthalmic instruments is feasibly as effective as full-cycle sterilization for contained instruments using the AMSCO autoclave. For sequential same-day ophthalmic procedures, wet instruments sterilized by a short-cycle process with an interrupted dry time can remain sterile for at least 3 minutes if kept in a covered sterilizer containment device. One guideline recommends that wrapped or unwrapped ophthalmic instruments sterilized by a short-cycle process without full drying should be stored in a covered containment device until retrieved by staff wearing sterile gloves and gowns in the operating room for the subsequent surgery after a short delay. Phaco handpieces should be immediately primed with a balanced salt solution and remain wet as they sit on the sterile instrument table. We did not identify any clinical setting evidence from studies or autoclave manufacturers. It is unclear if clinical outcomes differ between patients undergoing sequential same-day ophthalmic surgeries using short-cycle sterilized instruments and those undergoing surgery using full-cycle sterilized instruments. What Does This Mean? Preliminary laboratory evidence and guideline recommendations supporting the use of autoclaves for short-cycle sterilization of instruments for sequential same-day ophthalmic surgeries are available. However, there is no clinical effectiveness evidence available on this process in patient settings. Future research is necessary to understand the clinical safety of using instruments sterilized by short cycles for sequential same-day use for patients undergoing ophthalmic surgeries. In addition to the evidence and recommendations identified, other factors, such as environmental influence, may be useful considerations when making decisions about short-cycle sterilization for sequential same-day instrument use for ophthalmic surgery.

Enhancing the stability of soil contaminated with fluoride through the utilization of pristine and aluminium-impregnated biochar: a comprehensive mechanistic approach.

The effect of trivalent metal-modified biochar on the stability and mitigation of fluoride ions (F-) in contaminated soils remains largely unexplored, despite biochar's extensive application in F--contaminated soil. The mineral metal-modified biochar has the potential to serve as an efficient solution for soil contaminated with F-. In this study, pristine-pinecone biochar (P-BC) and AlCl3-modified pinecone biochar (A-BC) were synthesized and then utilized to remediate the soil that had been contaminated with F-. Both P-BC and A-BC efficiently immobilized F- within the contaminated soil. Further examinations through sequential extraction procedure and subsequent analysis using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and elemental dot mapping demonstrated a transformation of F- into a more stable state by A-BC treatment of the contaminated soil. This implies that A-BC may possess the capacity to function as an efficient ameliorant for immobilizing F- within the soil.

Dispersive analysis of excited glueball states

Abstract Motivated by the determination for the spin-parity quantum numbers of the $X(2370)$ meson at BESIII, we extend our dispersive analysis on hadronic ground states to excited states. The idea is to start with the dispersion relation which a correlation function obeys, and subtract the known ground-state contribution from the involved spectral density. Solving the resultant dispersion relation as an inverse problem with available operator-product-expansion inputs, we extract excited-state masses from the subtracted spectral density. This formalism is verified by means of the application to the series of $\rho$ resonances, which establishes the $\rho(770)$, $\rho(1450)$ and $\rho(1700)$ mesons one by one under the sequential subtraction procedure. Our previous study has suggested the admixture of the $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$ mesons (the $\eta(1760)$ meson) to be the lightest scalar (pseudoscalar) glueball. The present work predicts that the $f_0(2200)$ ($X(2370)$) meson is the first excited scalar (pseudoscalar) glueball.

Knowledge‐Guided Automated Cartographic Generalization Process Construction: A Case Study Based on Map Analysis of Public Maps of China

ABSTRACTThe efficacy of conveying information through maps heavily depends on the quality of map generalization. However, automating map generalization poses a complex decision‐making challenge, requiring a profound understanding of the process—specifically, knowledge about the generalization procedure. Currently, there is a scarcity of research on the sequence of generalization operations, particularly for cartographic generalization involving symbolization and labeling. On the contrary, customary maps generated in practical applications consistently adhere to the specified generalization and symbolization protocol, which makes it feasible and credible to construct this overall process based on expert knowledge. To reconcile this incongruity, this paper presents a knowledge‐guided automated cartographic generalization process construction. Firstly, an exhaustive examination of the sequential procedures involved in manual generalization and a well‐applied automated generalization system are delineated, drawing upon map analysis methodologies, observations, and expert interviews. Then, elaborate guidelines governing each phase within this process, particularly concerning the symbolization and labeling of map features, are explored. Ultimately, details of the expert interview are described and a map generalized by the well‐applied system is analyzed. The results show that the automated generalization system follows the knowledge‐guided process in this paper can significantly improve production efficiency in practice, this study serves as a connection between cartographers and developers and may help achieve a higher level of automated cartographic generalization.

Sequential label shift detection in classification data: An application to dengue fever.

Classifiers have been developed to help diagnose dengue fever in patients presenting with febrile symptoms. However, classifier predictions often rely on the assumption that new observations come from the same distribution as training data. If the population prevalence of dengue changes, as would happen with a dengue outbreak, it is important to raise an alarm as soon as possible, so that appropriate public health measures can be taken and also so that the classifier can be re-calibrated. In this paper, we consider the problem of detecting such a change in distribution in sequentially-observed, unlabeled classification data. We focus on label shift changes to the distribution, where the class priors shift but the class conditional distributions remain unchanged. We reduce this problem to the problem of detecting a change in the one-dimensional classifier scores, leading to simple nonparametric sequential changepoint detection procedures. Our procedures leverage classifier training data to estimate the detection statistic, and converge to their parametric counterparts in the size of the training data. In simulated outbreaks with real dengue data, we show that our method outperforms other detection procedures in this label shift setting.

Evaluating the Effects of Solid-Phase Cartridge Chemistry on Extraction of Bisphosphonates and ITPP From Equine Plasma.

Bisphosphonate drugs and myo-inositol trispyrophosphate are of concern to the racing industry and have been listed as prohibited substances in equine sports. The current bisphosphonate plasma screening analysis employed at the Australian Racing Forensic Laboratory involves the use of sequential solid-phase extraction procedures, passing the samples through a mixed mode cartridge, followed by a weak anion exchange cartridge. The eluates collected following the second extraction are then methylated and analysed by liquid chromatography-mass spectrometry. Under these extraction conditions, some bisphosphonates have shown poor recovery. To improve the extraction efficacy, the effects of cartridge chemistry were evaluated. In particular, the weak anion exchange cartridges used for screening were compared to an affinisep AttractSPE polymeric phase cartridge. The effectiveness of each extraction approach was assessed through both a visual comparison of signal to noise in extracted chromatograms and recovery measurements to determine the best approach for routine screening.

Evaluation of the remediation effect of solid waste synergistic materials on heavy metal-contaminated soil

In this study, we investigated the effect of various solid waste materials such as fly ash (CFA), steel slag, and kaolinite on the simultaneous stabilization of As, Cd, Cu, Pb, and Zn in the soil of abandoned lead-smelting slag plant. Synchronous stabilization of HMs in highly contaminated soils was achieved using the application of 29 % formulated material Fe/Ca-Si based co-remediation material (FCS) with a ratio of FeSO4 + CFA + kaolinite of 14 %: 12 %: 3 %, the bioavailable content of HMs As, Cd, Cu, Pb, and Zn was reduced by 71.55 %, 49.62 %, 91.35 %, 61.37 %, and 41.45 %, respectively, and had little effect on the pH of the soil. Leaching toxicity analyses guaranteed the safety of restorative materials. The results of the field validation experiments showed that the FCS was able to effectively reduce the content of HMs in plant rhizomes and stabilized with maintenance time. European Community Bureau of Reference (BCR) and Wenzel sequential extraction procedures showed that FCS promoted the transformation of HMs in soil from unstable to stable phases. The analysis of soil microbial community diversity by FCS showed that it created a favorable soil living environment for microorganisms and was conducive to the stabilization of HMs. SEM, Surface scanning analysis, XRD, and FTIR results showed that FCS reacts with HMs to form a stable phase. Cost analysis showed that it has certain economic benefits. In conclusion, FCS is feasible for soil remediation in lead-smelting slag-polluted areas and also provides a way for high value-added utilization of solid waste.

Syntheses of Diarylmethanes Via an Oxidative Benzylic Functionalization of P-Alkyl Phenol Derivatives Under Quaternary Ammonium Hypoiodite Catalysis.

We herein report two strategies for the quaternary ammonium hypoiodite-mediated oxidative benzylic functionalization of p-alkyl phenol derivatives. By using either dibenzoylperoxide or H2O2 in hexafluoroisopropanol in the presence of tetrabutyl ammonium iodide gives access to activated intermediates which can then be coupled with electron-rich aromatic compounds. Overall, this sequential two-step one-pot procedure gives access to diversely decorated diarylmethane derivatives straightforwardly. Furthermore, the suitability of these products to undergo further oxidation reactions was successfully demonstrated.

Deep learning permits imaging of multiple structures with the same fluorophores

Fluorescence microscopy, which employs fluorescent tags to label and observe cellular structures and their dynamics, is a powerful tool for life sciences. However, due to the spectral overlap between different dyes, a limited number of structures can be separately labeled and imaged for live-cell applications. In addition, the conventional sequential channel imaging procedure is quite time consuming, as it needs to switch either different lasers or filters. Here, we propose a novel double-structure network (DBSN) that consists of multiple connected models, which can extract six distinct subcellular structures from three raw images with only two separate fluorescent labels. DBSN combines the intensity-balance model to compensate for uneven fluorescent labels for different structures and the structure-separation model to extract multiple different structures with the same fluorescent labels. Therefore, DBSN breaks the bottleneck of the existing technologies and holds immense potential applications in the field of cell biology.

Self-Management Effect on Preeclampsia in Pregnant Women at RSI Jemursari Surabaya

The leading cause of mortality after infection and hemorrhage is preeclampsia. Preeclampsia can develop in a pregnant woman anywhere from the third trimester onwards, or after the 20th week of gestation. Finding out how self-management affects preeclampsia in pregnant women was the goal of this study at RSI Jemursari Surabaya. This study's pre-experimental design makes use of the One-Group Pre-Test and Post-Test methodology. The study's population consisted of sixty-two pregnant women diagnosed with preeclampsia at RSI Jemursari Surabaya. extracted with the use of a sequential non-random sampling procedure. One variable that may be controlled is preeclampsia, while another is self-management. The device used a preeclampsia observation sheet. In order to analyze the data, the Wilcoxon ranks test statistic was used, with a significance threshold of = 0.05. The results obtained from 53 respondents that before being given intervention there were severe preeclampsia (39.6%), mild preeclampsia (49.1%) of respondents, and superimposed (11.3%). 0%), mild preeclampsia (71.7%) and superimposed preeclampsia (11.3%). Analysis of the Wilcoxon ranks test statistical test obtained a significance value of P=0.001 so that H0 is rejected and H1 is accepted. Self Management has an effect on the incidence of preeclampsia, so pregnant women can do it independently and nurses are expected to be able to provide education in health services.

Sustainable reuse of modified incineration sewage sludge ash (M-ISSA) for stabilization of highly As-contaminated soil

Arsenic (As) is an environmental hazardous contaminant, seriously threatening human health. Chemical activation can effectively enhance As adsorption performance of incinerated sewage sludge ash (ISSA). Through modification, the iron (mainly present as hematite) in the ISSA was rearranged to KFeO2. Based on the results of the present study, addition of modified ISSA (M-ISSA) in contaminated soil had a positive effect on As immobilization. A set of laboratory batch experiments including toxicity characteristic leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), and sequential extraction procedure (SEP) were carried out to investigate effects of M-ISSA dosages and curing time on immobilization of As contaminated soil (100, 500, 1000 mg As/kg soil). Results indicated that a higher addition amount of M-ISSA enhanced the effectiveness of stabilization and significantly reduced the As leachability after a stabilization period of 28 d. Particularly, in 1000 mg As/kg soil, M-ISSA reduced the labile As concentration in the TCLP test from 21.45 to 0.73 mg/L and in the SPLP test from 27.75 mg/L to 7.83 mg/L. M-ISSA transformed As in soil to more stable forms that were bounded to amorphous iron hydrous oxides. The number of stable fractions saw a sharp rise from 31% to 60%, when the M-ISSA addition was 5%. Different characterizations were conducted including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM), in order to demonstrate the stabilization behavior and mechanism of As and M-ISSA. The main stabilization mechanism was associated with adsorption and coprecipitation processes. Overall, this study proposed a novel recycling method for ISSA that could be chemically modified into a reliable and efficient additive for the immobilization of As contaminated soil.

Critical condition for initiation of dynamic recrystallisation in electron beam powder bed fused Ti-6Al-4 V Alloy

Despite the unique capabilities of Additive Manufacturing (AM) processes for producing Ti components with complex geometries, the desired properties are only achievable if a holistic scheme is devised, considering the synergistic role of post-processing steps. This work aimed to enhance the applicability of metal AM products by improving the process chain in the manufacturing industry. For this purpose, the current work demonstrates a comprehensive investigation into the hot deformation of Ti-6Al-4 V (Ti64) pre-forms produced via the Electron Beam Powder Bed Fusion (EB-PBF) process focusing on the determination of critical conditions for initiating Dynamic Recrystallization (DRX) in these components. Following a sequential evaluation procedure, hot deformation experiments were carried out at temperatures ranging from 1000 to 1200 °C and strain rates of 0.001–1 s−1 to determine the critical stress and strain required for initiating DRX in Ti64 pre-forms and compare them to their wrought counterparts. In addition, a specific Finite Element Model (FEM) was coupled with DRX kinetics equations to predict the volume percentage of DRX grains during the hot deformation of the pre-forms. The analysis of flow stress curves showed a significant peak stress at low strains, which is then followed by a period of flow softening and eventually transitions into a nearly steady-state flow at higher strains. In addition, compared to their wrought counterparts, the EB-PBF samples exhibited a significantly superior flow softening behavior, as evidenced by a more significant volume fraction of DRX and faster recrystallisation rates. It was also revealed that the normalised strain for DRX initiation in the EB-PBF Ti64 and wrought one was 0.55 and 0.67, respectively. FEM results closely matched the experimental finding, confirming its reliability in providing valuable insights into microstructural evolution and offering a time-efficient alternative for process design and property optimisation, lowering dependence on trial-and-error approaches. Through a combination of experiments, numerical analysis, and finite element simulations, this study sheds light on the macroscopic deformation and microstructural transformations occurring during hot working processes.