Emission Spectroscopy Research Articles

Sustainable stabilization of waste foundry sands in alkali activated glass-based matrices

Since cements and concrete are highly energy-demanding, sustainable construction materials represent a crucial aspect in mitigating environmental pollution. The study proposes a promising solution for transforming waste into new and highly sustainable construction materials according to alkali activation process. The unemployed fractions of boro-alumino-silicate pharmaceutical glass (BASG) and waste foundry sands (WFS) were employed in the production of synthetic conglomerates. Glass powders were firstly suspended into ‘mild’ NaOH/KOH aqueous solutions (2.5–5 M) for 180 minutes at 500 rpm, at room temperature or at 40°C. Conglomerates were later produced by embedding of foundry sands in slurries of alkali activated glass, for BASG:WFS ratios of 1:1, 1:2 or 1:3. The mass of sand embedded is a function of the grain size distribution. A final drying phase, lasting 7 days at 40°C, promoted the consolidation of the newly-formed materials due to the formation of strong siloxane bonds. The obtained conglomerates were mechanically tested under compression. Interestingly, the composites exhibited a compressive strength-to-density ratio comparable with commercial insulating lightweight concrete and Plaster of Paris. Moreover, the leachates from conglomerates were subjected to optical emission spectroscopy in inductively coupled plasma (ICP-OES) to verify the stabilization of hazardous elements. The methodology selected for the stabilization of pollutants is compliant with UNI EN 12457–2:2002. The results show that the release of critical pollutants (Ba, Cr, Cd, Co, Mo, Ni) was maintained below the European limits. The research highlights the possibility to manufacture conglomerates starting from waste raw materials. Furthermore, stabilizing activity towards hazardous elements is achieved by all composite materials.

Magnetic curcumin–copper graphene oxide as facile and recyclable heterogeneous nanocatalyst for preparation of polyhydroquinolines and sulfoxides

In this research project, a versatile procedure has been designed for the preparation of supported copper@curcumin on magnetic graphene oxide nanoparticles (GO@Fe3O4@Cur–Cu). The structure of prepared nanocatalyst was characterized by several techniques including; Fourier transform infrared, powder X-ray diffraction, thermal gravimetric analysis, energy dispersive X-ray analysis, inductively coupled plasma optical emission spectroscopy, vibrating sample magnetometer, transmission electron microscopy, and scanning electron microscopy analyses. The catalytic properties of GO@Fe3O4@Cur–Cu were examined for the efficient synthesis of polyhydroquinolines as well as the preparation of sulfoxides through selective oxidation of sulfides in the presence of hydrogen peroxide.

The effect of activated water on lentil seed germination utilizing several plasma reactors and a hydrogen injection system

As a threat to meeting the global demand for food created by the continued growth of population, different methods are being applied to enhance seed germination and plant growth. This study investigates the effect of hydrogen-rich water (HRW) and different plasma-activated waters (PAW) and their combinations including HRW, PAW1, PAW2, HPAW1, and HPAW2 on the seed germination of lentils. Different arc discharge reactors are generated under atmospheric pressure in the air. Optical emission spectroscopy was used to detect the radiative species formed in the plasma zone. Raman spectra and physicochemical properties of different waters were investigated. The results demonstrated significant differences in the properties of different activated waters compared to control water. On day 3 after treatment, the fraction and length of germinated seeds were evaluated. During germination, treated water significantly increased germination parameters such as final germination percentage, mean germination time, germination index, and coefficient of germination velocity. HPAW2 exhibited the highest germination index (GI), which combines germination percentage and speed. The plasma systems also effectively reduced the pH of PAW1 and PAW2, with a greater decrease observed in HPAW1 and HPAW1. Analysis of nitrite and nitrate levels revealed that HPAW2 had the highest concentrations, indicating more reactive processes in the presence of hydrogen. Based on our results, it can be concluded that lentil seed germination can be increased using PAW and hydrogenated PAW combined.

Profiling and health risk assessment of trace metal contents in bovine tissues: A case study in Gondar City, Ethiopia

This study aimed to determine six trace metal (Cu, Mn, Zn, Cd, Cr, and Pb) concentrations in three bovine tissues (kidney, liver and muscle) from Gondar City abattoir, Ethiopia, and assess associated health risks. Samples were digested with HNO3/HClO4, and metal concentrations were analyzed by Inductively Coupled Plasma Optical Emission Spectroscopy. Zn exhibited the highest concentration in muscle (52.1 mg/kg), whereas Cd was below the LOD (0.6 µg/kg) in all muscle samples. The levels of Cd, Cr, and Mn in liver and kidney tissues, as well as Zn in muscle, exceeded FAO/WHO safety thresholds. Principal component analysis revealed distinct metal accumulation patterns among the tissues where liver is the target organ for accumulation of Pb, Mn and Cu, while kidney appears to be the organ of preference for Cd and Cr accumulation. Zn had the highest chronic daily intake for both children and adults, followed by Cu. Hazard index values for both age groups were below one, indicating no non-carcinogenic risks. However, the incremental lifetime cancer risks and cumulative carcinogenic risks of Cr exceeded the tolerable limit for adults and children, indicating a high cancer likelihood from this trace metal. In contrast, the incremental lifetime cancer risks of Pb for both adults and children were within acceptable limits. In conclusion, cumulative carcinogenic risk values indicate that consuming muscle tissue poses health risks for both adults and children, highlighting the need for stricter cattle feed regulations in the study area to safeguard public health.

Laser-Induced Breakdown Spectroscopy in Mineral Exploration and Ore Processing

Laser-induced breakdown spectroscopy (LIBS) is a type of optical emission spectroscopy capable of rapid, simultaneous multi-element analysis. LIBS is effective for the analysis of atmospheric gases, geological fluids, and a broad spectrum of minerals, rocks, sediments, and soils both in and outside the traditional laboratory setting. With the recent introduction of commercial laboratory systems and handheld analyzers for use outside the laboratory for real-time in situ analysis in the field, LIBS is finding increasing application across the geosciences. This article first overviews the LIBS technique and then reviews its application in the domain of mineral exploration and ore processing, where LIBS offers some unique capabilities.

Elemental Profiling of Common Anti-diabetic Medicinal Plants of Swat and Peshawar Districts of Khyber Pakhtunkhwa (KPK) Province of Pakistan: An Investigation Using PIXE and ICP-OES.

The use of medicinal plants is integral to addressing liver, heart, lung, and other metabolic issues. These plants are rich in vitamins, minerals, flavonoids, and alkaloids, which collectively help in lowering intestinal glucose absorption and increasing insulin secretion by pancreatic tissues. Elemental analysis, encompassing major, minor, and trace elements, was performed on various parts (leaves, roots, and seeds) of 16 anti-diabetic medicinal plants collected from different regions of Swat and Peshawar in Khyber Pakhtunkhwa (KPK), Pakistan. This analysis utilized proton-induced X-ray emission (PIXE) and inductively coupled plasma optical emission spectroscopy (ICP-OES) techniques. Our PIXE and ICP-OES analysis revealed the presence of major (Ca, K, S, P), minor (Si, Cl), and trace (Al, Mn, Fe, Ni, Cu, Zn, Se, Cr, and Sc) elements in various parts (leaves, roots, and seeds) of the 16 anti-diabetic medicinal plants studied. Specifically, elements such as Ca, K, Cr, Cu, Mn, Zn, and Se were detected, all of which are known to contribute in maintaining normal glucose metabolism. Notably, Zn and Se are crucial trace elements for the synthesis, secretion, and action of insulin. Significant Zn concentrations were observed in ten anti-diabetic medicinal plants: Albizia lebbeck (AL), Atropa acuminata (AA), Avena fatua (AF), Citrus medica (CM), Commiphora wightii (CW), Cymbopogon citratus (CC), Daucus carota (DC), Ziziphus mauritiana (FM), Hyoscyamus niger (HN), and Martynia annua (MA), and significant Se concentrations were observed in twelve medicinal plants, i.e., Albizia lebbeck (AL), Allium sativum (AS), Atropa acuminata (AA), Avena fatua (AF), Cannabis sativa (CS), Capparis spinosa (CaS), Commiphora wightii (CW), Cymbopogon citratus (CC), Datura alba (DA), Daucus carota (DC), Ziziphus mauritiana (FM), and Hyoscyamus niger (HN). Our study's elemental analysis using PIXE and ICP-OES on various parts of 16 medicinal plants identified a significant number of useful elements. Elements such as Ca, K, S, P, Al, Si, Cl, Mn, Fe, Ni, Cu, Zn, Se, and Cr were identified and quantified. These findings support the potential use of these plants in managing diabetes and highlight the importance of elemental profiling in understanding their therapeutic properties.

Plant-Based Alternatives to Mold-Ripened Cheeses as an Innovation among Dairy Analogues.

There is a growing demand for vegan products and plant-based food when dealing with the impact of livestock on the climate crisis. The aim of this study was to develop a formulation for a plant-based analogue of mold-ripened cheese. Were investigated the following plant materials: cashews, pistachios, soy flour, chickpea flour, pea protein, pumpkin protein, hemp protein, and spirulina powder. Plant matrices were fermented with lactic acid bacteria (LAB) starter cultures and cheese starter cultures of mold species Geotrichum candidum and Penicillium camemberti. All microorganisms' growth were tested in a vegan-type culture medium. Calcium supplementation was applied and followed by an in-depth analysis of the elemental composition of selected analogues with inductively coupled plasma optical emission spectroscopy. The physicochemical and organoleptic analyses of plant-based alternatives of Camembert were conducted. This is the first paper describing novel formulations for plant-based alternatives for Camembert cheese prepared with techniques mimicking the original milk product.

Optical Characteristics of a New Molecular Complex: "Nafion-Colloidal CdSe/CdS/ZnS Nanocrystals".

Here, the optical properties of the Nafion polymer membrane containing colloidal CdSe/CdS/ZnS nanocrystals embedded by diffusion have been studied. The CdSe/CdS/ZnS nanocrystals have a core/shell/shell appearance. All experiments were carried out at room temperature (22 ± 2) °C. A toluene solution was used to provide mobility to the active sulfone groups of the Nafion membrane and to embed the nanocrystals inside the membrane. The diffusion process of colloidal CdSe/CdS/ZnS nanocrystals into Nafion proton exchange membrane has resulted in a new molecular complex "Nafion-colloidal CdSe/CdS/ZnS nanocrystals". The kinetics of the nanocrystals embedding into the membrane matrix was investigated using luminescence analysis and absorption spectroscopy techniques. The embedding rate of CdSe/CdS/ZnS nanocrystals into the Nafion polymer membrane was approximately 4·10-3 min-1. The presence of new luminescence centers in the membrane was proved independently by laser emission spectroscopy. The luminescence spectrum of the resulting molecular complex contains intensity maxima at wavelengths of 538, 588, 643 and 700 nm. The additional luminescence maximum observed at the 643 nm wavelength was not recorded in the original membrane, solvent or in the spectrum of the semiconductor nanoparticles. The luminescence maximum of the colloidal CdSe/CdS/ZnS nanocrystals was registered at a wavelength of 634 nm. The intensity of the luminescence spectrum of the membrane with embedded nanocrystals was found to be higher than the intensity of the secondary emission peak of the initial nanocrystals, which is important for the practical use of the "Nafion-colloidal nanocrystals" complex in optical systems. The lines contained in the luminescence spectrum of the membrane, which has been in solution with colloidal nanocrystals for a long time, registered upon its drying, show the kinetics of the formation of the molecular complex "Nafion membrane-nanocrystals". Colloidal nanocrystals located in the Nafion matrix represent an analog of a luminescent transducer.

Metal content, bioaccumulation, translocation, and health risk assessment of root vegetables grown in KwaZulu-Natal small-scale farms of South Africa.

Metal uptake by vegetables is becoming a threat to the life of consumers. Therefore, continuous monitoring of metals in vegetables and soils is becoming a necessity. In this study, the occurrence of 18 metals in amadumbe (Colocasia esculenta L.), sweet potatoes (Ipomoea batatas L.), potatoes (Solanum tuberosum L.), and carrots (Daucus carrota L.) grown in small-scale South African agricultural farms was monitored using inductively coupled plasma-optical emission spectroscopy. All the 18 investigated elements were detected in soils and different vegetative plants parts. Bioaccumulation factors indicated the transfer of selected metals from soils into the plant roots. Toxic metals Cd, Cr, and Pb had their concentrations exceeding the maximum permissible levels set by the World Health Organization in the edible parts of all root vegetables. Cd and Pb varied between 18.89 and 19.19mgkg-1 and 10.46 and 11.46mgkg-1, respectively, while Cr remained constant at 16.78mgkg-1. The exact metals together with As and Ni had their total hazard quotients exceeding the threshold value of 1, which indicated that the daily consumption of the investigated root vegetables is likely to pose health risks to both adults and children. Therefore, this study points out to a possibility of toxic health effects that could arise when these vegetables are consumed daily.

Combustion enhancement in a model scramjet by a simple pin-to-pin AC arc plasma

A simple pin-to-pin alternative-current (AC) arc plasma located upstream of the cavity was developed to achieve significant combustion enhancement in a Mach 2.52 C2H4-fueled and cavity-based model scramjet. The arc plasma-enhanced combustion process was recorded by high-speed CH⁎ chemiluminescence imaging, optical emission spectroscopy, static pressure measurements, and discharge waveform measurements. In the absence of the arc plasma, the flame heat release intensity was low, and the heat release region was located at the shear layer of the cavity; the flame stayed in a relatively weak combustion state and even appeared in a lower heat release intensity. Once the arc plasma was turned on, the static pressure of the model scramjet at the typical positions was increased by up to 9 %, and the flame area and the flame intensity were significantly enhanced. In the presence of the arc plasma, the position of the flame heat release region moved upstream and even caused the long-scale displacement for the flame with a higher heat release intensity several times. The arc plasma provided a large number of reactive species and Joule heat at the practical influence region of the arc plasma, which contributed to igniting an initial flame upstream of the cavity. The propagation and development of the continuous initial flame generated by the arc plasma can enable the flame to be more frequently transferred into the cavity-assisted jet-wake stabilized combustion mode, leading to significant combustion enhancement.

Determination of Essential Minerals in the Indigenous Vegetables Solanum nigrum (Stout Shade) and Gynandropsis gynandra (Spider Plant) from Two Agroecological Zones in Kisii County, Kenya.

Vegetables are good sources of essential mineral elements that promote good health and immunity. Information on the nutritional contents of indigenous vegetables is scarce. Therefore, this study sought to ascertain the concentrations of magnesium, manganese, chrome, zinc, copper, and iron in Solanum nigrum and Gynandropsis gynandra indigenous vegetables from two agroecological zones (upper midland and lower highland) of Kisii County, Kenya, using inductively coupled plasma optical emission spectroscopy (ICP‒OES). For Gnandropsis gynandra, the most abundant erythrocytic synthesis element was Fe (1856.67 ± 15.28mg/kg DW) for plants harvested from Nyanchwa (UM), and the least was Cu (8.90 ± 0.44mg/kg DW) in plants harvested from Kari (LH). In addition, Mg was the hypoglycemic element with the highest concentration (5975.00 ± 10.00mg/kg DW), and Cr lowest (3.16 ± 0.45mg/kg DW) in samples harvested from Matongo (UM). For Solanum nigrum, the most erythrocytic synthesis element was Fe (1280.00 ± 10.00mg/kg DW for samples collected from Kiamabundu (UM), and the least was Cu (9.08 ± 0.15mg/kg DW) in the samples from Nyanchwa (UM), whereas Mg in samples from Nyabioto (UM) was the hypoglycemic element with the highest concentration (4920.00 ± 10.00mg/kg DW) and Cr in samples from Mariba (LH had the lowest concentration) (3.95 ± 1.63mg/kg DW). The concentrations of elements in the two indigenous vegetables from the UM agroecological zone were slightly greater than those in the LH agroecological zone. Nonetheless, the variations observed were not statistically significant (P < 0.05). Enzymatically bio accessed concentrations of iron, zinc, chromium, magnesium, manganese, and copper were higher than those obtained aquatically. The indigenous vegetable bio avails substantial amounts of iron and copper to enable them be used in the management pernicious anaemia; on the other hand, the substantial bio availed levels of zinc, manganese, magnesium, and chromium enables the vegetable to be used in the management of diabetes.

Assessment of coffee leaves nutritive value via portable X-ray fluorescence spectrometry and machine learning algorithms

Portable X-ray fluorescence (pXRF) spectrometry is a non-destructive technique that has been successfully used to analyze different matrices. Foliar analysis is challenging because some plant nutrients cannot be detected by pXRF. Even so, the uptake interactions among nutrients which reflect different concentrations of macro- and micronutrients can be accessed via pXRF, constituting a basis to obtain predictive models of plant nutrients. The objective of this work was to compare and assess the accuracy of linear regression and non-linear models (support vector machine – SVM; and random forest – RF) to predict the actual concentration of macro- (N, P, K, Ca, Mg, and S) and micronutrients (B, Cu, Fe, Zn, and Mn) in coffee leaves. A greenhouse experiment was conducted using Hoagland and Arnon solution to obtain leaves with contrasting elemental composition. Ground and oven-dried leaf samples were analyzed via pXRF using: i) a manufactured pXRF calibration developed for general earth-materials (Geoexploration mode); ii) the Spectrometer mode with varying voltage and current (15 kV and 25 μA; 10 kV and 10 μA). The same samples were also analyzed via conventional acid digestion and quantified via inductively coupled plasma-optical emission spectroscopy (ICP-OES). The best predictions were obtained using SVM and RF algorithms, with high R2 (0.82 to 0.99) and high residual prediction deviation (RPD) (2.35 to 9.34) values. However, some elements (e.g., K, Ca, Cu, Mn) were successfully predicted using linear models (LR and MLR). Even elements not detected (N and B) by pXRF were accurately predicted using the RF model. The pXRF operational conditions influenced the performance of the models. However, by parsimony, Geoexploration mode provided data for accurate prediction of macro- and micronutrients. This comprehensive study can potentially spark further investigations into examining coffee leaves from plants cultivated under various environmental and management conditions. Additionally, the methodological framework outlined here holds promise for ongoing experimentation across diverse crops, offering a streamlined, non-invasive, eco-friendly, and rapid approach for foliar analysis.

Real-time detection of molecular structures and metal components within airborne particles using concurrent Raman and Spark emission spectroscopy

Real-time detection of molecular structures and metal components within airborne particles using concurrent Raman and Spark emission spectroscopy

Investigating the efficiency of electrocoagulation using similar/dissimilar electrodes for the detoxification of Coralene Rubine dye: a cost effective approach.

Efficient treatment of textile dyeing wastewater can be achieved through electrocoagulation (EC) with minimal sludge production; however, the selection of the appropriate electrode is essential in lowering overall costs. Also, the reuse of the treated aqueous azo dye solution from this process has not been explored in detail. With these objectives, this study aims to treat synthetic azo dye solutions and achieve high colour removal efficiency (CRE%) using similar (Ti-Ti) and dissimilar (Ti-Cu) metal electrodes through EC with an attempt to reduce the cost. The aqueous Coralene Rubine GFL azo dye was used to examine the efficiency and cost of the EC process. X-Ray Photoelectron Spectroscopy was used to study the EC mechanism, while High Performance Liquid Chromatography was used to analyse the degradation of the dye and the formation of intermediate compounds. The concentration of metal ions in the treated dye solution was quantified using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), with Ti-Ti treated solution having 14.20mg/L concentration of Ti and Ti-Cu treated solution having 0.078mg/L of Ti and 0.001mg/L of Cu, respectively. Colour removal efficiency of 99.49% was obtained for both electrode sets, with a lower operating time and voltage for dissimilar metal combination. Ecotoxicity studies showed negligible toxicity of Ti-Cu treated dye samples compared to untreated solutions. Survival rate, protein estimation, and catalase activity was used to validate the treatment method's efficacy. The study found that the dissimilar electrode material exhibited reduced toxicity due to the presence of heavy metals below the permissible limit.

Real-time confinement regime detection in fusion plasmas with convolutional neural networks and high-bandwidth edge fluctuation measurements

A real-time detection of the plasma confinement regime can enable new advanced plasma control capabilities for both the access to and sustainment of enhanced confinement regimes in fusion devices. For example, a real-time indication of the confinement regime can facilitate transition to the high-performing wide-pedestal (WP) quiescent H-mode, or avoid unwanted transitions to lower confinement regimes that may induce plasma termination. To demonstrate real-time confinement regime detection, we use the 2D beam emission spectroscopy (BES) diagnostic system to capture localized density fluctuations of long wavelength turbulent modes in the edge region at a 1 MHz sampling rate. BES data from 330 discharges in either L-mode, H-mode, quiescent H (QH)-mode, or WP QH-mode were collected from the DIII-D tokamak and curated to develop a high-quality database to train a deep-learning classification model for real-time confinement detection. We utilize the 6×8 spatial configuration with a time window of 1024 µs and recast the input to obtain spectral-like features via fast Fourier transform preprocessing. We employ a shallow 3D convolutional neural network for the multivariate time-series classification task and utilize a softmax in the final dense layer to retrieve a probability distribution over the different confinement regimes. Our model classifies the global confinement state on 44 unseen test discharges with an average F 1 score of 0.94, using only ∼1 ms snippets of BES data at a time. This activity demonstrates the feasibility for real-time data analysis of fluctuation diagnostics in future devices such as ITER, where the need for reliable and advanced plasma control is urgent.

A new device for high-resolution Li K X-ray spectroscopy using an electron microprobe

Lithium is one of the key elements in today's materials and battery industry, and the interest in non-destructive characterization techniques at a micron scale for materials containing lithium is steadily increasing. The electron microprobe is a reliable and accessible analysis tool widely used for this purpose, but performing X-ray emission spectroscopy in the low-energy range is still challenging.In this work, we demonstrate that spectroscopy in the Li K energy range is feasible by integrating a new detection system composed of a multilayer and ultra-thin separation windows into a commercial wavelength dispersive spectrometer of a microprobe. The detection system is described in detail, and the results, in form of spectra showing the Li K emission in LiF and in a ternary quasicrystalline sample, are presented and analyzed. In LiF the emission band is centered at 54.5 eV and has varying intensities for different beam exposure times. The spectra obtained in the ternary quasicrystal clearly demonstrate that the detection system has sufficient energy resolution to separate the Li emission band and the Al L2,3 and Cu M2,3 emission bands, enabling chemical state analysis by comparing the shapes of the emissions. To our knowledge, this is the first time such a detection system, implemented in a WDS spectrometer and enabling the acquisition of different Li K spectra in various compounds has been described in detail. This kind of system can be used for Li quantification using a common procedure in electron probe microanalysis.

Nitrogen modified graphene nanowalls for retrieval of trace level cerium from aqueous medium

Removal of cerium from environmental and aqueous streams is essential in waste water rejuvenation processes. Nitrogen modified graphene nano walls (N-GNWs) have shown ultra-high sorption efficiency of trivalent cerium from aqueous medium (Kd > 2 × 107) and a large sorption capacity of ∼ 2500 mg/g is achieved. N-GNWs were deposited on carbon paper substrate using PECVD technique. The three-dimensional nature of N-GNWs are revealed from high resolution FESEM images. Raman spectroscopic studies have shown that GNWs are defective and possess a few layer graphene like structure. Secondary Ion Mass Spectroscopic studies of the Ce sorbed N-GNWs and optical emission spectroscopy of the residual solution confirm the sorptive retrieval of cerium. Visual Minteq based ionization model is introduced to explain high (>90 %) sorption of Ce at pH≥7 and the mechanistic aspects of sorption for standard Cerium solution is discussed. The sorption involves attachment of cerium hydroxyl ions to the active cites on the sorbent surface.

3D Nickel–Manganese bimetallic electrocatalysts for an enhanced hydrogen evolution reaction performance in simulated seawater/alkaline natural seawater

In this paper, we report an inexpensive one-step synthesis of self-supported 3D nickel-manganese (NiMn) bimetallic coatings and their application for the hydrogen evolution reaction in simulated seawater (1 M KOH + 0.5 M NaCl) and alkaline natural seawater (1 M KOH + natural seawater). These binary coatings were electrodeposited on a titanium substrate using a facile electrochemical deposition method by a dynamic hydrogen bubble template technique. The as-deposited NiMn coatings with variable Mn amounts produce typical globular and unique porous architecture with abundant pores of different sizes. The activity of these fabricated catalysts towards the hydrogen evolution reaction was investigated by linear sweep voltammetry towards simulated seawater and alkaline natural seawater at different temperatures. The surface morphology and composition of the catalysts were also characterized by scanning electron microscopy and inductively coupled plasma optical emission spectroscopy. The as-prepared NiMn/Ti electrocatalyst, which was electrodeposited using a chemical bath containing Ni2+ and Mn2+ ions with a molar ratio of Ni2+:Mn2+ = 1:5, exhibits excellent hydrogen evolution activity in simulated seawater with an ultra-low overpotential of 64.2 mV to reach a current density of 10 mA cm−2. It is noteworthy that this NiMn/Ti electrocatalyst also achieves a current density of 10 mA cm−2 in alkaline natural seawater with a comparably low overpotential of 79.3 mV. The current densities increase by ca. 1.75–2.35 times with an increase in temperature from 25 °C to 75 °C for hydrogen evolution in both electrolytes. This bimetallic catalyst has shown excellent long-term stability at a constant potential of −0.23 V (vs. RHE) and a constant current density of 10 mA cm−2 for 10 h, which ensures higher durability and robustness for practical application of seawater splitting technology.

Direct mechanistic connection between acoustic signals and melt pool morphology during laser powder bed fusion

Various nondestructive diagnostic techniques have been proposed for in situ process monitoring of laser powder bed fusion (LPBF), including melt pool pyrometry, whole-layer optical imaging, acoustic emission, atomic emission spectroscopy, high speed melt pool imaging, and thermionic emission. Correlations between these in situ monitoring signals and defect formation have been demonstrated with acoustic signals having been shown to predict pore formation with especially high confidence in recent machine learning studies. In this work, time-resolved acoustic data are collected in both the conduction and keyhole welding regimes of LPBF-processed Ti-6Al-4V alloy. A non-dimensionalized Strouhal number analysis, used in whistle aeroacoustics, is applied to demonstrate that the acoustic signals recorded in the keyhole regimes can be directly associated with the vapor depression morphology. This mechanistic understanding developed from whistle aeroacoustics shows that acoustic monitoring during the LPBF process can provide a direct probe into the vapor depression dynamics and defect occurrence, especially in the keyhole regimes relevant to printing and defect formation.

Correlation Between Severity of Schizophrenia with Certain Trace Elements and TNF-α Gene Expression and Its Circulatory Level in the Population of Western India.

This cross-sectional study aimed to assess serum trace element (TE) concentrations, TNF-α gene expression, protein levels in schizophrenia (SZ) patients, and their correlation with disease severity measured by Positive and Negative Syndrome Scale (PANSS) scores. Forty SZ cases and 40 healthy controls aged 18-60 were recruited. Forty (n = 40) cases who meet ICD-10 criteria for SZ and 40 (n = 40) healthy individuals (controls) between 18 and 60years of age were recruited in the study. Sandwich enzyme-linked immunosorbent assay (ELISA) and RT-qPCR (quantitative real-time PCR) were used to estimate pro-inflammatory cytokine TNF-α protein and gene expression. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) and graphite furnace atomic absorption spectroscopy (GFAAS) were used to assess serum levels of trace elements (TEs): Fe, Zn, Cu, Mg, and Se. Compared to healthy controls, cases had significantly higher levels of TNF-α protein, as well as Fe, Cu, and Se (p < 0.05). Cu correlated positively with TNF-α protein level (rho = 0.234; p = 0.048) and gene expression (rho = 0.333; p = 0.041) and with PANSS negative (rho = 0.531), general (rho = 0.643), and total (rho = 0.541) scores. Additionally, Zn negatively correlated with serum Mg (rho = - 0.426, p < 0.01) and positively with serum Se (rho = 0.343, p < 0.05). In conclusion, elevated Cu levels could potentially contribute to the development of SZ. Elevated Cu levels in cases and their correlation with the TNF-α gene and protein and PANSS score indicate Cu's potential role in exacerbating SZ severity through inflammatory cytokines. This suggests the involvement of metals and cytokines in the pathophysiology of SZ.