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This article employs fluid equations to analyze muon beams in gases subject to crossed electric and magnetic fields, focusing, in particular, on a scheme proposed by Taqqu [Phys. Rev. Lett. 97, 194801 (2006)], whereby transverse compression of the beam is achieved by creating a density gradient in the gas. A general criterion for maximizing beam compression, derived from first principles, is then applied to determine optimal experimental conditions for μ+ in helium gas. Although the calculations require the input of transport data for (μ+, He), which are generally unavailable, this issue is circumvented by "aliasing" (μ+, He) with (H+, He), for which transport coefficient data are available. [ABSTRACT FROM AUTHOR]

In this series, we outline a strategy for analyzing electrons and muons in gases in crossed electric and magnetic fields using the straightforward transport equations of momentum-transfer theory, plus empirical arguments. The method, which can be carried through from first principles to provide numerical estimates of quantities of experimental interest, offers a straightforward, physically transparent alternative to "off-the-shelf" simulation packages, such as Magboltz and GEANT. In this first article, we show how swarm data for electrons in helium gas subject to an electric field only can be incorporated into the analysis to generate electron swarm properties in helium gas in crossed electric and magnetic fields and to estimate the Lorentz angle in particular. The subsequent articles in the series analyze muons in crossed fields using similar transport theory, though the absence of muon swarm data requires empiricism of quite a different nature. [ABSTRACT FROM AUTHOR]

Here, we present a new approach for obtaining radial distribution functions (RDF) from the electron diffraction data using a regularized weighted sine least-squares spectral analysis. It allows for explicitly transferring the measured experimental uncertainties in the reduced molecular scattering function to the produced RDF. We provide a numerical demonstration, discuss the uncertainties and correlations in the RDFs, and suggest a regularization parameter choice criterion. The approach is also applicable for other diffraction data, e.g., for x-ray or neutron diffraction of liquid samples. [ABSTRACT FROM AUTHOR]

Transparent alumina ceramics produced by pulsed electric current sintering (PECS) include black dots, which can be observed with the naked eye. These black dots have porous structures caused by the aggregates in the raw powder. In order to investigate the detailed mechanism of black dot formation, transparent alumina ceramics were prepared by sintering α-alumina granules to produce large pseudo-aggregates and introducing them into α-alumina powder for PECS. Macroscopic black dots were formed in the sample. Characteristic Raman peaks of graphite were detected in porous parts of these macroscopic black dots. Analysis of gas phases generated from graphite sheets for PECS suspected to be involved in carbon contamination showed CO and CO 2 generation. In thermodynamic calculations on carbon activity during PECS, gas phase including CO and CO 2 generated from the hot graphite mold/sheet permeates the porous part of the cold sample, and the carbon activity of gases including CO and CO 2 on the porous surface theoretically exceeds unity. Then, CO is adsorbed and decomposed on the porous surface, resulting in carbon contamination. The formation of macroscopic black dots is caused by carbon deposition in agglomerates of the raw powder from CO generated by graphite sheets during PECS. [ABSTRACT FROM AUTHOR]

A tubular proton‐conducting fuel cell, anode‐supported, was fabricated using dip‐coating and followed by the co‐sintering of anode and electrolyte at 1500°C. The electrolyte and anode thicknesses are respectively 6 and 500 µm. The outer diameter of the tubular cell is 5.8 mm, featuring an anode porosity of 23%. Ammonia‐fueled single cell with Ru‐catalyzed internal cracking reactor is operated at various temperatures from 400°C to 600°C. Calculation results indicate that double‐ring current collection is an efficient current‐collecting mode. At 600°C, the device exhibited a high open‐circuit voltage of 1.02 V and a peak power density of 216 mW cm−2, with a total active area of 2.28 cm2. Exhaust gas analysis reveals a 99.13% ammonia decomposition rate at 600°C. [ABSTRACT FROM AUTHOR]

A simple, rapid, and sensitive procedure is developed for the determination of hydroxylated polycyclic aromatic hydrocarbons (2-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyphenanthrene, 3-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1-hydroxypyrene, and 6-hydroxychrysene) in urine by gas chromatography–mass spectrometry. Sample preparation is based on dispersive liquid–liquid microextraction with trichloromethane in an acidic medium. Derivatization is carried out in a heated injector port using the reagent N,O-bistrimethylsilyltrifluoroacetamide. The type of dispersing solvent is experimentally selected and the optimal ratio of the following factors, i.e., pH value, volume of dispersing solvent, and extraction time, is found using a three-factor experiment. A high-temperature capillary column NT-8 is used in a temperature gradient mode for analysis by gas chromatography–mass spectrometry. The linearity range of the calibration function is found to be 0.5–100 ng/mL. The developed procedure for determining hydroxylated PAH in urine is tested on urine samples from aluminum production workers. [ABSTRACT FROM AUTHOR]

A technology is developed for manufacturing planar microfluidic chips (MFCs) based on Silgard 8040, encompassing template fabrication, mold production, sealing, and adsorbent filling. These MFCs, filled with a Porapak-Q adsorbent, facilitate sample preparation and calibration under uniform conditions, integrating both sample collection and preconcentration stages. Experimental investigations have identified optimal conditions for acetone preconcentration using Silgard 8040-based MFCs, achieving a maximum concentration factor of 43 at adsorption temperature (Tads) of 0°C, desorption temperature (Tdes) of 70°C, adsorption volume (Vads) of 45 mL, and desorption time (tdes) of 1 s. The feasibility of using MFCs for sample collection and preparation, taking into account sample storage time, has been evaluated. The procedure maintains accuracy within 6–10% over 8 h without a necessity for additional drying of the collected samples from exhaled air. [ABSTRACT FROM AUTHOR]

In this review article, the main techniques for spectroscopic studies of gases in field conditions are considered. The issues related to the study of gas emissions from soils and the determination of their concentrations are analysed. The main types of spectroscopy used in portable devices for soil gas analysis, along with their design features and sampling approaches, are provided. Various studies aimed at optimising the operation of devices for analysing gases emitted from the soil, taking into account agronomic, agrochemical, and ecological specifics, are also presented. The effect of using different types of lasers and reflecting elements on the accuracy of optical measurements and the sensitivity to various substances in the gases is analysed. [ABSTRACT FROM AUTHOR]

Dissolved gas analysis (DGA) is considered to be the most convenient and effective approach for transformer fault diagnosis. Due to their excellent performance and development potential, chemiresistive gas sensors are anticipated to supersede the traditional gas chromatography analysis in the dissolved gas analysis of transformers. However, their high operating temperature and high power consumption restrict their deployment in battery-powered devices. This review examines the underlying principles of chemiresistive gas sensors. It comprehensively summarizes recent advances in low-power gas sensors for the detection of dissolved fault characteristic gases (H2, C2H2, CH4, C2H6, C2H4, CO, and CO2). Emphasis is placed on the synthesis methods of sensitive materials and their properties. The investigations have yielded substantial experimental data, indicating that adjusting the particle size and morphology structure of the sensitive materials and combining them with noble metal doping are the principal methods for enhancing the sensitivity performance and reducing the power consumption of chemiresistive gas sensors. Additionally, strategies to overcome the significant challenge of cross-sensitivity encountered in applications are provided. Finally, the future development direction of chemiresistive gas sensors for DGA is envisioned, offering guidance for developing and applying novel gas-sensitive sensors in transformer fault diagnosis. [ABSTRACT FROM AUTHOR]

Background: This proof-of-concept study aimed to assess the diagnostic potential of gas chromatography–mass spectrometry (GC-MS) in profiling volatile organic compounds (VOCs) from exhaled breath as a diagnostic tool for the chronic coronary syndrome (CCS). Methods: Exhaled air was collected from patients undergoing invasive coronary angiography (ICA), with all samples obtained prior to ICA. Post hoc, patients were divided into groups based on coronary lesion severity and indications for revascularization. VOCs in the breath samples were analyzed using GC-MS. Results: This study included 23 patients, of whom 11 did not require myocardial revascularization and 12 did. GC-MS analysis successfully classified 10 of the 11 patients without the need for revascularization (sensitivity of 91%), and 7 of the 12 patients required revascularization (specificity 58%). In subgroup analysis, GC-MS demonstrated 100% sensitivity in identifying patients with significant coronary lesions requiring intervention when the cohort was divided into three groups. A total of 36 VOCs, including acetone, ethanol, and phenol, were identified as distinguishing markers between patient groups. Conclusions: Patients with CCS exhibited a unique fingerprint of exhaled breath, which was detectable with GC-MS. These findings suggest that GC-MS analysis could be a reliable and non-invasive diagnostic tool for CCS. Further studies with larger cohorts are necessary to validate these results and explore the potential integration of VOC analysis into clinical practice. [ABSTRACT FROM AUTHOR]

Elemental analysis is a fundamental method for determining the carbon, hydrogen, nitrogen, sulphur, and oxygen (CHNSO) contents in organic materials. Automated conventional elemental analysers are commonly used for CHNSO determinations, but they face challenges when analysing volatile organic liquids due to sample losses. This present study explores the combination of gas chromatography–mass spectrometry (GC/MS) and gas chromatography–flame ionisation detection (GC/FID) as a more accurate alternative method for elemental analysis of such liquids. Six different liquid samples containing various organic compounds have been analysed using both a conventional elemental analyser (Method 1) and the combined GC/MS–GC/FID method (Method 2). The results showed that Method 1 gave results with significant errors for carbon (by more than ±10 wt%) and oxygen (by up to ±30 wt%) contents due to volatile losses leading to inaccurate "oxygen-by-difference" determinations. In contrast, Method 2 gave more accurate and consistently representative elemental data in a set of simulated samples when compared to theoretical elemental data. This work proposes the use of the GC/FID method as a reliable alternative for CHNSO analysis of volatile organic liquids and suggests that employing the GC/FID technique can mitigate the common errors associated with conventional CHNSO analysis of such samples. However, successfully using Method 2 would depend on the skills and experience of users in qualitative and quantitative organic chemical analyses by gas chromatography. [ABSTRACT FROM AUTHOR]

The synergy effect of high K-low Ca-high Si biomass ash-based model system (BAMS) on the synthesis gas output and reaction characteristics of petroleum coke (PC) steam gasification process was studied using three biomass ash (BA) components, KCl, SiO2, and CaCO3, which were used as the model compounds. In the ternary model system, the steam gasification experiment of PC was conducted using a fixed bed reactor and gas phase chromatography. The synergistic effects of binary and ternary components in the ternary model system on the gasification of PC were obtained. These investigations were based on the data from the gas analysis and examined the gasification reaction process, syngas release behavior, and reaction characteristics. This study examined the effects of binary and ternary components in the ternary model system on the evolution of semi-char structure during PC gasification. This correlation revealed the synergistic effect of the model system on PC gasification. Scanning electron microscope (SEM) and Raman spectroscopy were used to characterize the structure and surface microstructure of the gasification semi-char. The results showed that the yields of different gases in the ternary model system were in H2 > CO > CO2. Compared with single PC gasification, the yields of H2, CO, syngas, and carbon conversion were increased by 29.42 mmol/g, 20.40 mmol/g, 56.68 mmol/g, and 0.35, respectively. All other components in the ternary model system with high K-low Ca-high Si demonstrated catalytic effect, except for SiO2 and the Ca-Si system, which showed inhibitory effects on syngas release and reaction features. Integrating SEM and Raman spectroscopic analyses, it was elucidated that CaCO3 and KCl diminished the degree of graphitization in semi-char through interactions with the carbonaceous matrix. This phenomenon facilitated the gasification process and exhibited a synergistic effect. Secondly, SiO2 will react with CaCO3 and KCl, producing inert silicates and inactivating these compounds, leading to the decline of catalysis. [ABSTRACT FROM AUTHOR]

• Direct and indirect climate impacts of solid waste landfills in California were quantified. • Direct impacts were positive and high whereas indirect impacts were negative and low. • Cover characteristics including material type and areal extent control climate impacts. • Global warming potential time horizon significantly influences climate impact results. • Integration of direct and indirect impacts advances landfill climate mitigation strategies. Climate impacts of landfill gas emissions were investigated for 20- and 100-year time horizons to identify the effects of atmospheric lifetimes of short- and long-lived drivers. Direct and indirect climate impacts were determined for methane and 79 trace species. The impacts were quantified using global warming potential, GWP (direct and indirect); atmospheric degradation (direct); tropospheric ozone forming potential (indirect); secondary aerosol forming potential (indirect) and stratospheric ozone depleting potential (indirect). Effects of cover characteristics, landfill operational conditions, and season on emissions were assessed. Analysis was conducted at five operating municipal solid waste landfills in California, which collectively contained 13% of the waste in place in the state. Climate impacts were determined to be primarily due to direct emissions (99.5 to 115%) with indirect emissions contributing −15 to 0.5%. Methane emissions were 35 to 99% of the total emissions and the remainder mainly greenhouse gases (hydro)chlorofluorocarbons (up to 42% of total emissions) and nitrous oxide. Cover types affected emissions, where the highest emissions were generally from intermediate covers with the largest relative landfill surface areas. Landfill-specific direct emissions varied between 683 and 103,411 and between 381 and 37,925 Mg CO 2 -eq./yr for 20- and 100-yr time horizons, respectively. Total emissions (direct + indirect) were 680 to 103,600 (20-yr) and were 374 to 38,108 (100-yr) Mg CO 2 -eq./yr. Analysis time horizon significantly affected emissions. The 20-yr direct and total emissions were consistently higher than the 100-yr emissions by up to 2.5 times. Detailed analysis of time-dependent climate effects can inform strategies to mitigate climate change impacts of landfill gas emissions. [ABSTRACT FROM AUTHOR]

To improve the homogeneity of heating, the magnetic absorbing material Fe3O4 is considered to use in microwave pyrolysis of oily sludge. Therefore, the effect of Fe3O4 on the microwave pyrolysis of oily sludge is investigated based on gas volatile products. Thermogravimetric mass spectrometry result certifies that Fe3O4 will increase the weight-loss ratio from 13.0% to 14.1%. Also, the characteristic peak intensity of CO in gas products decreases from 5.41 × 10−10 A/g to 1.95 × 10−10 A/g, while H2O increases from 3.57 × 10−10 A/g to 7.32 × 10−10 A/g and CO2 increases from 6.87 × 10−10 A/g to 8.92 × 10−10 A/g. This is caused by the esterification of alcohols and esters and the reduction of Fe3O4 by CO. Based on the decrease in activation energy and enthalpy values of Stage II and IV, it infers that Fe3O4 catalyzes the pyrolysis process of oily sludge to some extent. Similarly, gas chromatography-mass spectrometry results show that Fe3O4 can make the types of gas products increase. Especially, the number of molecular species increases from 5 to 46 under 200–300 °C. Finally, a simple molecular dynamics simulation model is conducted, and the results are in agreement with the experimental results. This study shows that Fe3O4 improves the pyrolysis homogeneity and the pyrolysis efficiency also improves. [ABSTRACT FROM AUTHOR]

The cathode surface of sulfide‐based all‐solid‐state batteries (SBs) is commonly coated with amorphous‐LiNbO3 in order to stabilize charge–discharge reactions. However, high‐voltage charging diminishes the advantages, which is caused by problems with the amorphous‐LiNbO3 coating layer. This study has investigated the degradation of amorphous‐LiNbO3 coating layer directly during the high‐voltage charging of SBs. O2 generation via Li extraction from the amorphous‐LiNbO3 coating layer is observed using electrochemical gas analysis and electrochemical X‐ray photoelectron spectroscopy. This O2 leads to the formation of an oxidative solid electrolyte (SE) around the coating layer and degrades the battery performance. On the other hand, elemental substitution (i.e., amorphous‐LiNbxP1‐xO3) reduces O2 release, leading to stable high‐voltage charge–discharge reactions of SBs. The results have emphasized that the suppression of O2 generation is a key factor in improving the energy density of SBs. [ABSTRACT FROM AUTHOR]

Background: Helminthiasis is a major concern in the livestock sector due to the immense afflictions in the production and economy of the farmer. Chemical anthelmintics are used to combat them and parasites are acquiring resistance against these drugs. Hence, the development of new drugs or alternatives is the need of the hour for combating such infestations. This study was undertaken to determine the effect of methanolic leaf extract of Tectona grandis on strongyles. Materials and Methods: The dried leaves of Tectona grandis were subjected to Soxhlet extraction using methanol, and the extract was tested for its anthelmintic activity in vitro using egg hatch assay and larval motility assay. A dose of 250, 125, 62.5, 31.25, 15.625, and 7.8125 mg/ mL was used for the study. Fresh strongyle ova were exposed to different concentrations of the extract and observed after 48 hours for the hatch. L3 larvae obtained from coproculture were subjected to treatment with extract at different concentrations, and mortality per unit time was calculated. Fourier transform infrared (FTIR) spectroscopic analysis and Gas chromatography-mass spectrometry (GC/MS) were performed to identify the chemical nature of the extract. Results: There was a dose-dependent inhibition of hatch and larval mortality with a maximum inhibition of hatch at 250 mg/mL. There was a cent percent hatch in control wells and no loss of progressive motility in the larval motility test. On exposure to the extract, the larvae progressively lost their motility, and finally, there were caesurae of movement which indicated their death. The extract at 250 mg/mL killed all the larvae by 30 min, whereas, at 31.25 mg/mL, the mortality was 66.6% after 2 hr. Conclusion: The results suggest that methanolic extract from Tectona grandis leaves has a promising anthelmintic property and further studies are required for the isolation of active molecules. [ABSTRACT FROM AUTHOR]

Premise: Poikilohydric plants respond to hydration by undergoing dry–wet–dry cycles. Carbon balance represents the net gain or loss of carbon from each cycle. Here we present the first standard protocol for measuring carbon balance, including a custom‐modified chamber system for infrared gas analysis, 12‐h continuous monitoring, resolution of plant–substrate relationships, and in‐chamber specimen hydration. Methods and Results: We applied the carbon balance technique to capture responses to water stress in populations of the moss Syntrichia caninervis, comparing 19 associated physiological variables. Carbon balance was negative in desiccation‐acclimated (field‐collected) mosses, which exhibited large respiratory losses. Contrastingly, carbon balance was positive in hydration‐acclimated (lab‐cultivated) mosses, which began exhibiting net carbon uptake <15 min following hydration. Conclusions: Carbon balance is a functional trait indicative of physiological performance, hydration stress, and survival in poikilohydric plants, and the carbon balance method can be applied broadly across taxa to test hypotheses related to environmental stress and global change. [ABSTRACT FROM AUTHOR]

Estimating gas transport through a hierarchical micro/nanoporous system is challenging due to non-equilibrium gas dynamics. The primary difficulty lies in determining the rarefaction level, because identifying a representative flow dimension in a complex porous system with multiple pore scales is not straightforward. Our study performed a pore-level analysis for gas permeability in dual-scale porous media with varying porosity, throat size, and secondary pore size under different rarefaction conditions. We found that secondary porosity negatively affects permeability due to increased friction forces, with this influence growing as the secondary pore size and porosity increase until the secondary pore becomes comparable to the throat. However, rarefaction reduces the effects of secondary pores due to boundary slip. Traditional Knudsen number (Kn) calculations based on Darcy-defined height failed to accurately describe the rarefaction effects on gas permeability. Instead, we introduced an equivalent diameter to calculate the Kn, which provided an accurate normalization of apparent gas permeability independent of pore geometry. The extended Kozeny–Carman–Klinkenberg model developed in our previous study successfully yielded a macroscopic model for apparent gas permeability in hierarchical micro/nanoporous systems as a function of the traditional Darcy height and porosity. [ABSTRACT FROM AUTHOR]

Liquid smoke is a food additive and cresols are among its chemical constituents, potentially toxic to human health. Thus, the objective of this study was to develop a method to quantify cresols in liquid smoke. First, the liquid-liquid extraction with low temperature purification (LLE-LTP) was validated for cresols in water, as there are no cresol-free liquid smoke samples. Analyzes were performed by gas chromatography coupled to mass spectrometry in full scan mode. LLE-LTP was subsequently applied in five commercial samples of liquid smoke. Validation results showed that the proposed extraction method was selective for cresols, linear in the range of 0.5 to 35 mg L−1, limit of quantification of 0.5 mg L−1, recovery rate between 90% and 104% and relative standard deviation lower than 10%. The quantification of cresols in liquid smoke samples ranged from 3.0 to 38.3 mg L−1 and the concentration of these chemical contaminants in liquid smoke remained constant for at least 21 days at 25 °C. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) are employed in a range of devices due to their high energy and power density. However, the increased power density of LIBs raises concerns regarding their safety when subjected to external abuse. The thermal behavior is influenced by a number of factors, i.e., the state of charge (SoC), the cell chemistry and the abuse conditions. In this study, three distinct cylindrical Li-ion cells, i.e., lithium nickel cobalt aluminum oxide (NCA), lithium titanate oxide (LTO), and lithium iron phosphate (LFP), were subjected to thermal abuse (heating rate of 5 °C/min) in an air flow reactor, with 100% SoC. Venting and thermal runaway (TR) were recorded in terms of temperature and pressure, while the emitted products (gas, solid, and liquid) were subjected to analysis by FT-IR and ICP-OES. The concentrations of the toxic gases (HF, CO) are significantly in excess of the Immediate Danger to Life or Health Limit (IDLH). Furthermore, it is observed that the solid particles are the result of electrode degradation (metallic nature), whereas the liquid aerosol is derived from the electrolyte solvent. It is therefore evident that in the event of a LIB fire, in order to enhance the safety of the emergency responders, it is necessary to use appropriate personal protective equipment (PPE) in order to minimize exposure to toxic substances, i.e., particles and aerosol. [ABSTRACT FROM AUTHOR]

Three-dimensional printing is ideally suited to produce unique and complex shapes. In this study, the material properties of polysiloxanes, commonly named silicones, produced additively by two different methods, namely, multi-jet fusion (MJF) and material extrusion (ME) with liquid printing heads, are investigated. The chemical composition was compared via Fourier-transform infrared spectroscopy, evolved gas analysis mass spectrometry, pyrolysis gas chromatography coupled to mass spectrometry, and thermogravimetry (TGA). Density and low-temperature flexibility, mechanical properties and crosslink distance via freezing point depression were measured before and after post-treatment at elevated temperatures. The results show significant differences in the chemical composition, material properties, as well as surface quality of the tested products produced by the two manufacturing routes. Chemical analysis indicates that the investigated MJF materials contain acrylate moieties, possibly isobornyl acrylate linking branches. The hardness of the MJF samples is associated with crosslinking density. In the ashes after TGA, traces of phosphorus were found, which could originate from initiators or catalysts of the curing process. The ME materials contain fillers, most probably silica, that differ in their amount. It is possible that silica also plays a role in the processing to stabilize the extrusion strand. For the harder material, a higher crosslink density was found, which was supported also by the other tested properties. The MJF samples have smooth surfaces, while the ME samples show grooved surface structures typical for the material extrusion process. Post-treatment did not improve the material properties. In the MJF samples, significant color changes were observed. [ABSTRACT FROM AUTHOR]

The main purpose of this study was to optimize the methods for determining methane emission in a continuously flooded (CF) and an alternately wetted and dried rice system. A field experiment was conducted at Block B1, Pili Drive, Los Baños, Laguna for one cropping season to evaluate the CH4 emission in both FP and AWD treatment plots. Fertilizer application rates were similar across treatments and were based on the recommended rate. Gas sampling was done weekly at 0, 15, and 30 - minute intervals and gas samples were analyzed using a gas chromatograph equipped with a flame-ionization detector (FID). Results showed that FP plots emitted methane at 15.07 to 459.14 mg CH4 day-1 m-2, which was higher than those produced in AWD plots which ranged from 1.68 to 36.26 mg CH4 day-1 m-2 throughout the cropping period. In both treatments, a decreasing trend in methane emission was observed which was attributed to the depleting carbon source of methanotrophs where methane was utilized rather than produced at an unfavorable redox potential for methane production. Global warming potential (GWP) of 7.000 kg CO2-eq and 1.350 kg CO2-eq was contributed by FP and AWD treatments, respectively. Overall, CH4 emission was reduced by 80-85% when AWD was employed without having a yield compromise. The result of this pilot study is limited to a 1.300 m2 field area but it showed a significant comparison between the two water management strategies in rice systems. Also, the learnings in this study will be used further for landscape greenhouse gas measurements in major rice-producing areas in the Philippines and ultimately will contribute to the carbon footprint assessment of rice cultivation. [ABSTRACT FROM AUTHOR]

Transformers are among the most important components in the energy grid due to their missions and high costs. The challenging operating conditions deteriorate their components and shorten the life of the transformers. The health index approach is a critical and effective method for monitoring transformers in the operating environment, early diagnosis of possible malfunctions, and evaluation of their general condition. DGA, OQA, and PIF parameters, which represent the condition of the insulation materials, which mainly determine the life of transformers, constitute the basic inputs of the health index approach. In this study, a new method was proposed to determine the DGAF score based on the dissolved gases in mineral oil. With this method, in addition to the delta and rate values of the gases, the past DGA results of the transformer were also considered in determining the DGAF. In this way, faults experienced during operation are included in the health index calculation. The proposed method was tested using 36 DGA results obtained over a period of approximately 10 years from a transformer operating in the grid. The obtained results are presented in comparison with the traditional DGAF scoring method. [ABSTRACT FROM AUTHOR]

Montmorillonite is a layered clay mineral whose modification by pillaring, i.e., insertion of oxide nanoclusters between the layers, yields porous materials of great potential in sorption and catalysis. In the present study, an unrefined industrial bentonite from Kopernica (Slovakia), containing ca. 70% of montmorillonite, was used for the preparation of Ti-, Zr-, and mixed [Ti,Zr]-pillared clay sorbents. The pillared samples were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and N2 adsorption at −196 °C and tested for the capacity of CO2 sorption at 0 °C and 1 bar pressure. The experiments revealed that pillared samples sorbed at least four times more CO2 than the parent bentonite. Of the materials tested, the sample pillared with mixed [Ti,Zr] oxide props showed the best performance, which was attributed to its superior microporosity. The results of CO2 adsorption demonstrated that the cost-effective use of crude industrial bentonite as the sorbent precursor is a viable synthesis option. In another experiment, all pillared montmorillonites were subjected to 24 h exposure at room temperature to a flow of dry CO2 and then tested using simultaneous thermal analysis (STA) and the mass spectrometry (MS) analysis of the evolving gases (STA/QMS). It was found that interaction with dry CO2 reduces the amount of bound carbon dioxide and affects the processes of dehydration, dehydroxylation, and the mode of CO2 binding in the pillared structure. [ABSTRACT FROM AUTHOR]

To explore the influence of raw materials from different cultivars on the quality of Sichuan dark tea, the raw materials of 4 tea cultivars were used in this study. The main chemicals and aroma components were analyzed by sensory evaluation, chemical analysis and gas chromato graphy-mass spectrometry (GC-MS) . The main components of Sichuan dark teas made from different tea cultivars were significantly different. The contents of water extract, tea polyphenols, catechins and caffeine of Sichuan dark teas from 'Zijuan' were the highest, which were 49.45%, 18.54%, 4.77%, and 4.21%, respectively, followed by Sichuan dark tea processed with 'Huangjinya' cultivar, all of them were significantly (P<0.05) higher than the Sichuan dark tea processed with 'Fuding Dabai' and 'Baiye 1'. The contents of L-asparagine, L-theanine, aspartic acid and glutamic acid were the highest of Sichuan dark teas from 'Huangjinya', which were 115.78, 279.86, 154.47, 70.76 mg/100 g, respectively, significantly (P<0.05) higher than Sichuan dark tea processed with other cultivars. Aroma analysis showed that main aroma components were alcohols, aldehydes, ketones, hydrocarbons and esters, accounting for more than 80% of the total aroma. The similarity rate of aroma between 'Fuding Dabai' and 'Baiye 1' was 0.98, and that of 'Huangjinya' and 'Zijuan' was 0.99. The Sichuan dark tea processed with the 'Baiye 1' had floral fragrance, and the Sichuan dark tea processed with the 'Zijuan' had ''stale flavor''. Sensory quality analysis showed that the comprehensive qualities of Sichuan dark teas from 'Fuding Dabai','Baiye 1' and 'Huangjinya' were the better, with a score of more than 82, while the Sichuan dark tea from 'Zijuan' had the lowest score. The Sichuan dark tea processed with 'Huangjinya' materials was rich in substances and had good comprehensive quality. The Sichuan dark tea processed with 'Baiye 1' material had floral fragrance, which could be used as a variety for processing advanced special Sichuan dark tea. The Sichuan dark tea processed with 'Zijuan' materials had high content of water extracts and tea polyphenols, with ''stale flavor''. It was suitable for blending and processing with other cultivars of low polyphenol content, and could be used as a blending variety for dark tea products with ''stale flavor''. [ABSTRACT FROM AUTHOR]

Introduction: It has been suggested that the mechanism of phloem loading, that is apoplastic or symplastic loading, may affect a plant's ability to adapt to elevated CO2 levels. Strawberry (Fragaria × ananassa) and tomato (Solanum lycopersicum) are two fruit crops that use different mechanisms to load sugars into the phloem - the former symplastically and the latter apoplastically - yet both species can increase their yields when grown in a CO2-enriched environment. In this study, we subjected strawberry and tomato plants to long-term CO2 enrichment to determine the morphological and physiological adaptations that enable them to increase their yields in response to higher CO2 levels. Methods: Transplanted tomato and strawberry plants were subjected to ambient (400 ppm) and elevated (800 ppm) CO2 for three months. We examined various parameters associated with growth, yield, photosynthesis, and carbon allocation by means of phenotyping, gas exchange analysis, and 13C labelling combined with isotope ratio mass spectrometry. Results: We found that CO2 enrichment promoted growth and reproductive development in both species, resulting in more flowers per plant (tomato and strawberry), larger crown (strawberry), and, eventually, higher yields. Gas exchange analysis and A/ci curves revealed that elevated CO2 increased carbon assimilation rate in strawberry, but not in tomato - the latter being limited by Rubisco's carboxylation efficiency. Finally, whereas both species prioritized fruit development over the development of other sink organs, they were both limited by carbon export at elevated CO2, since new photoassimilates were equally distributed to various sinks between CO2 treatments. Discussion: The findings suggest that both species will benefit from future increases in CO2 levels and support current glasshouse practices entailing CO2 enrichment. Those benefits probably stem from an enhanced performance of both species at early developmental stages, as differences in carbon assimilation rate (tomato) and carbon allocation between treatments at late developmental stages were absent. Moreover, crop adaptation to elevated CO2 seems to depend on the ability of each species to respond to elevated CO2, rather than on the phloem loading mechanism per se. [ABSTRACT FROM AUTHOR]

Introduction: All citrus plants are rich sources of phytochemicals that have many beneficial effects on human health. Different parts of the Citrus Limon plant, such as fruits, leaves, seeds, stems, and peels, also contain a wide spectrum of phytochemicals with therapeutic effects. Aim: The present study focused on phytochemical analysis and Gas Chromatography Mass Spectrometry (GCMS) profiling of limon peel. Materials and Methods: An experimental qualitative analysis was conducted at Systemic Life Sciences and Research in Hyderabad, Telangana, India from April 2023 to April 2024. Fresh Citrus Limon fruits were collected from an authorised vendor, identified, and authenticated. The peels were dried, coarse powdered, and a methanolic extract was prepared using the Soxhlet extraction method. An experimental qualitative analysis GCMS was performed to identify the chemical compounds present in the Citrus Limon peel extract. Results: Phytochemical analysis of Citrus Limon peel showed the presence of various metabolites such as carbohydrates, proteins, alkaloids, tannins, flavonoids, saponins, steroids, terpenoids, and glycosides. The GCMS profiling identified 13 chemical compounds, most notably Pentamethoxyflavone, Tetramethoxyflavone, and 2-Methoxy-4-vinylphenol in the methanolic extract of Citrus Limon peel. Conclusion: It was concluded that the bioactive phytocomponents are abundant in Citrus Limon peel extract. [ABSTRACT FROM AUTHOR]

Background and Aims: Caffeine is a xanthine alkaloid found naturally in plants. Caffeine has cardiotonic and stimulant effects in humans and animals. For this reason, caffeine is on the monitoring list for human sports and is listed as a feed contaminant in horse racing. The aim of this study was to develop a rapid, practical, and specific method for the determination of caffeine in horse urine. Methods: In the new method, the pH of the sample was adjusted by the addition of phosphate buffer, and after solid phase extraction, it was dissolved in methanol before being analysed by gas chromatography mass spectrometry without derivatization. The method was validated according to the European Commission’s 2002/657/EC criteria. Results: The effects of different cartridge brands, pH, and elution solution were determined. Intraday and interday CV% values are 2.8 and 5.2 for the International Residue Limit (IRL), respectively. Five levels (blank, 0.5xIRL, IRL, 1.5xIRL, and 2xIRL) were used in constructing the curve, and the R2 value was greater than 0.99. The analysis run was 11.8 min. The decision limit (CCα) was determined to be 56.7 ng/mL due to IRL. The detection limit of the method was calculated to be 3.3 ng/mL. The method was determined to be robust according to changes in extraction pH, phosphate buffer concentration, centrifugation time, hexane volume in the wash step, different grades of methanol, inlet temperature, and operator. Conclusion: The applicability of the method was demonstrated by analysing positive and negative horse urine samples. Validation parameters showed the method to be selective, specific, and easy to apply. [ABSTRACT FROM AUTHOR]

In this study, the types of fatty acids in the liver tissue of mice were evaluated under different diets. As a result, mice fed with a high-fat diet-including basic pellets mixed with eight percent (w/w) peanut oil, two percent (w/w) cholesterol, and 0.1% (w/w) calcium carbonate-showed the highest cholesterol content (1.5 ± 0.08 mg/100 g) compared to normal mice (0.23 ± 0.04 mg/100 g). Whereas the cholesterol content in the liver tissue of mice fed with basic pellets and orally treated with a free fatty acid fraction (FFA1) from virgin coconut oil, which was made up of the C8:0-C12:0 fraction (97.3%) was prepared did not differ from the control group (using only standard pellets). This demonstrated that MCFA (C8:0-C12:0) was directly consumed and converted to energy without accumulating cholesterol. The gas chromatography analysis result showed that the fat droplets in the liver tissues of treated mice were mostly saturated long-chain fatty acids (LCFA), in which C16:0 and C18:0 carbon chain length fatty acids were predominant in the liver tissue. The results confirmed the hypothesis that MCFA is preferentially absorbed and converted to energy while saturated LCFA has a tendency to induce fat accumulation in the metabolic pathway. [ABSTRACT FROM AUTHOR]

Lithium iron phosphate (LFP) batteries are widely utilized in energy storage systems due to their numerous advantages. However, their further development is impeded by the issue of thermal runaway. This paper offers a comparative analysis of gas generation in thermal runaway incidents resulting from two abuse scenarios: thermal abuse and electrical abuse. The study initially focuses on 13-Ah lithium iron phosphate single-cell batteries. Experiments were conducted to induce thermal runaway through both forms of abuse, analyzing the production and dispersion of H2 and CO gases in each case. It was observed that thermal abuse–induced thermal runaway resulted in higher gas concentrations and more pronounced fluctuations, whereas electrical abuse–induced thermal runaway exhibited lower gas concentrations and lower fluctuations. Subsequently, key materials and temperature variations at the positive and negative electrodes were investigated under both types of thermal runaway, revealing distinct differences that are identified as the primary reasons for the significant disparities in H2 and CO gas generation during the two thermal runaway conditions. The conclusions drawn in this paper advance the understanding of the mechanisms underlying H2 and CO gas concentration generation in thermal runaway scenarios. [ABSTRACT FROM AUTHOR]

The work is devoted to the study of the distribution of γ-hexachlorocyclohexane in turnips and beets between their bulbs, tops, and skin. The sample preparation procedure recommended by GOST is supplemented by the use of liquid nitrogen for the deeper crushing and destruction of plant cells. It was found that the use of liquid nitrogen, with other experimental parameters being constant, leads to a 2–3-fold increase in the amount of the pesticide being determined. It was found that the distribution of γ-HCCH in plants is uneven: the highest concentration of the pesticide is found in the skin, while the amount of γ-HCCH in the tops was the lowest. It was shown that the pesticide is better accumulated in beet skin than in turnip skin; for the tops the pattern is reversed, and the accumulation of γ-HCCH in the bulbs of these root crops is similar in magnitude. The obtained data can be useful for analytical quality control services of agricultural products. [ABSTRACT FROM AUTHOR]

In this study, we report a compact and versatile gas sensor system combining mid-infrared interband cascade light emitting diodes (MIR-ICLEDs) with substrate-integrated hollow waveguides (iHWGs) toward miniaturized gas sensors. Two readily exchangeable MIR-ICLEDs with center emission wavelengths of 3.4 µm (2941 cm−1) and 5.7 µm (1754 cm−1), respectively, were integrated into a modular sensor system using the iHWG simultaneously as a miniaturized gas cell. The performance of the sensor system for quantitative analysis was evaluated based on calibration functions established for four analytes (i.e., methane, isobutane, acetone, and acetaldehyde) within the respective spectral regions. The utility of such a sensor system as a non-dispersive infrared sensor was tested for various scenarios, including the application of spectral filters, the performance of the individual ICLEDs, and in the analysis of gas mixtures. Furthermore, we demonstrated that the modularity of the sensor design facilitates flexible adaptation to target gas species and available sample volumes, differentiating individual components within gas mixtures. [ABSTRACT FROM AUTHOR]

The problem of corrosion in oil and gas pipelines is one of the major factors affecting the process safety and efficient sustainability development of the oil and gas industry. To gain a better understanding of global research trends and dynamics in the field of oil and gas pipeline corrosion and to advance the development of corrosion control technology, we conducted a literature review using a sample of 1,745 papers from the Web of Science (WOS) database published from 2002 to 2022. We employed a bibliometric analysis approach employed to investigate the distribution of publications over time, geographic regions, major organizations, major authors, journal cocitation, and literature cocitation, and to identify research hotspots and frontiers. The results revealed an exponential growth in the overall number of papers, with the most rapid increase occurring in the last 4 years. China, the US, Canada, the United Kingdom, and Brazil emerged as the most active countries in oil and natural gas pipeline corrosion research, and Mexico, Canada, and Australia also exhibited significant influence in the field. The journals Engineering Failure Analysis, Corrosion, and Corrosion Science had the highest number of publications and impact in this domain. Notably, Corrosion Science stood out as the most influential and highly regarded journal in the corrosion field. The fundamental theories and research framework in the realm of oil and natural gas pipeline corrosion have been primarily established, and a large number of research directions and frontier branches are emerging. The impact of flow parameters on corrosion, pipeline reliability assessment, and analysis of corrosion defects and failures are identified as the three main development paths in this field. In terms of research methodologies, machine learning techniques are becoming increasingly prevalent, with a growing number of studies adopting various machine learning methods. Among these methods, explainable deep learning is at the forefront of development in the field of oil and natural gas pipeline corrosion. [ABSTRACT FROM AUTHOR]

The transformer plays a critical role in maintaining the stability and smooth operation of the entire power system, particularly in power transmission and distribution. The paper begins by providing an overview of traditional fault diagnosis methods for transformers, including dissolved gas analysis and vibration analysis techniques, elucidating their developmental trajectory. Building upon these traditional methods, numerous researchers have aimed to enhance and optimize them through intelligent technologies such as neural networks, machine learning, and support vector machines. These researchers have addressed common issues in traditional fault diagnosis methods, such as the low correlation between characteristic parameters and faults, ambiguous fault descriptions, and the complexity of feature analysis. However, due to the complexity of transformer structures and the uncertainties in operating environments, the collection and analysis of characteristic parameters becomes highly intricate. Researchers have further refined algorithms and feature values based on intelligent diagnostic algorithms for transformers. The goal is to improve diagnostic speed, mitigate the impact of measurement noise, and further advance the adaptability of artificial intelligence technology in the field of transformers. On the other hand, the excellent multi-parameter analysis capability of artificial intelligence technology is more suitable for transformer diagnostic techniques that involve the fusion of multiple information sources. Through the powerful data acquisition, processing, and decision-making capabilities provided by intelligent algorithms, it can comprehensively analyze non-electrical parameters such as oil and gas characteristics, vibration signals, temperature, along with electrical parameters like short-circuit reactance and load ratio. Moreover, it can automatically analyze the inherent relationship between faults and characteristic quantities and provide decision-making suggestions. This technique plays a pivotal role in ensuring transformer safety and power network security, emerging as a prominent direction in transformer fault diagnosis research. [ABSTRACT FROM AUTHOR]

The power transformer is an invaluable piece of device in the power system. To prevent catastrophic failures and the ensuing power outages, the status of a transformer linked to a system must be examined for any possible faults. Despite using DGA as a global tool for detecting faults, it is limited by the inability to accurately solve the problem associated with results variability due to the intrinsic nature of the IEC TC 10 database. This study proposed a data-driven fault/defect diagnostic model using four ensemble models with three base classifiers respectively. The base classifiers are comprised of SVM, C4.5 decision tree, and naive Bayes while the ensemble methods are comprised of stacking, voting, boosting and bagging respectively. The DGA dataset used comprises seven features and 168 instances split into training (i.e. 56%) and test (i.e. 44%) datasets respectively. The results indicate that C4.5 obtained a 98.33% accuracy while stacking obtained a 99.89% accuracy as the bestperforming base and ensemble models respectively. The high classification performance accuracy achieved by our proposed models indicates its capacity for real-world applications. It can be applied to advance automation in mobile-based technology. [ABSTRACT FROM AUTHOR]

The paper reports the effects of organic fertilisers on the photosynthetic characteristics and growth of soybean plants. The photosynthetic parameters were performed through gas exchange analysis by chlorophyll a fluorescence emission, in three phenological stages of culture. Photosynthetic activity, liquid CO₂ assimilation rates, stomatal conductance and water use efficiency were favoured by the addition of organic fertilisers to the soil. The addition of organic fertilisers reduced the initial chlorophyll a fluorescence, increased the electron transport rate, the internal CO₂ concentration, the potential efficiency of photosystem (II) and the effective quantum efficiency of photosystem (II) in soybean plants. [ABSTRACT FROM AUTHOR]

Aims: Frailty is an obstacle to performing cardiopulmonary exercise test (CPET) in patients with chronic heart failure (CHF). We evaluated the usefulness of oxygen uptake efficiency slope (OUES) using a 6 min walk test (6MWT) with portable gas analysis compared with CPET‐derived parameters in patients with CHF. Methods and results: Patients with CHF who underwent both the 6MWT with portable gas analysis and CPET between December 2016 and May 2020 were retrospectively investigated. The 6MWT‐derived and echocardiographic parameters were compared with the OUES and peak oxygen consumption (VO2) from the CPET. Forty patients were analysed; 50% were male with a mean age of 55.45 ± 14.70 years. Twenty‐six patients (65%) had New York Heart Association Functional Classification II or III dyspnoea. Twenty‐five patients (62.5%) had heart failure (HF) with preserved ejection fraction (EF) (left ventricular EF > 50%), and nine patients (22.5%) had HF with reduced EF (EF < 40%). During the 6MWT, the peak VO2 was 14.97 ± 3.80 mL/kg/min, which was only 74% of the peak VO2 in the CPET, 20.18 ± 5.64 mL/kg/min. The OUES in the 6MWT was lower than that in the CPET (1528.87 ± 579.01 in the 6MWT vs. 1638.69 ± 601.31 in the CPET). The 6 min walk distance (6MWD) and OUES in the 6MWT were positively correlated with the OUES in the CPET (6MWD, r = 0.434, P = 0.005; OUES, r = 0.729, P < 0.001). The OUES in the 6MWT showed the strongest correlation with the OUES in the CPET. When we divided patients into two groups according to peak VO2 in the CPET, the correlation between OUES values of the 6MWT and that of the CPET was consistently confirmed (peak VO2 ≥ 20 mL/kg/min group, r = 0.661, P = 0.001; peak VO2 < 20 mL/kg/min group, r = 0.526, P = 0.021). In addition, the 6MWD, OUES, and peak VO2 in the 6MWT were associated with peak VO2 in the CPET (6MWD, r = 0.627, P < 0.001; OUES, r = 0.452, P = 0.003; and peak VO2, r = 0.492, P = 0.001). Conclusions: In frail patients with CHF who have difficulty performing maximal exercises, the OUES through the 6MWT may be applied instead of the OUES and peak VO2 from the CPET. [ABSTRACT FROM AUTHOR]

The integrated CO2 capture and utilization coupled with the reverse water-gas shift reaction (ICCU-RWGS) presents an alternative pathway for converting captured CO2 into CO in situ. This study investigates the effectiveness of three calcium-based materials (natural limestone, sol-gel CaCO3, and commercial CaCO3) as dual-functional materials (DFMs) for the ICCU-RWGS process at intermediate temperatures (650–750 °C). Our approach involves a fixed-bed reactor coupled with mass spectrometry and in situ Fourier transform infrared (FTIR) measurements to examine cyclic CO2 capture behavior, detailed physical and chemical properties, and morphology. The in situ FTIR results revealed the dominance of the RWGS route and exhibited self-catalytic activity across all calcium-based materials. Particularly, the natural limestone demonstrated a CO yield of 12.7 mmol g−1 with 100% CO selectivity and 81% CO2 conversion. Over the 20th cycle, a decrease in CO2 capture capacity was observed: sol-gel CaCO3, natural limestone, and commercial CaCO3 showed reductions of 44%, 61%, and 59%, respectively. This suggests inevitable deactivation during cyclic reactions in the ICCU-RWGS process, while the skeleton structure effectively prevents agglomeration in Ca-based materials, particularly in sol-gel CaCO3. These insights, coupled with the cost-effectiveness of CaO-alone DFMs, offer promising avenues for efficient and economically viable ICCU-RWGS processes. [ABSTRACT FROM AUTHOR]

Methyl ester is considered one of the alternative substitutes to mineral oil as an insulating liquid. This study investigates the dissolved gas analysis (DGA) of the methyl ester derived from palm oil, under low energy discharge faults. The aims are to understand the gas composition and evaluate the applicability of the well-established fault interpretation methods for mineral oil to the methyl ester. Experimental procedures were conducted based on the International Electrotechnical Commission (IEC) standards. It involved simulating electrical breakdowns in laboratory conditions as per IEC-156 standard and analyzing gas samples using gas chromatography based on IEC-567. Results show that methyl ester oils produce similar types of gases as mineral oils but at higher concentrations. The interpretation of DGA results using fault identification methods such as Duval Triangle, Duval Pentagon, and IEC ratio indicates an overestimation of fault severity in methyl ester oils, and categorizing the faults as high energy discharge. However, the key gas method correctly identifies the discharge in both methyl ester and mineral oils. These findings suggest the need for adjustments in existing DGA methods to account for the higher gas concentrations in methyl ester oils, for effective condition monitoring and maintenance of transformers if it was filled with methyl ester oil. [ABSTRACT FROM AUTHOR]

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Untargeted analysis of gas chromatography–high-resolution mass spectrometry (GC-HRMS) data is a key and time-consuming challenge for identifying metabolite markers in food authentication applications. Few studies have been performed to evaluate the capability of untargeted data processing tools for feature extraction, metabolite annotation, and marker selection from untargeted GC-HRMS data since most of them are focused on liquid chromatography (LC) analysis. In this framework, this study provides a comprehensive evaluation of data analysis tools for GC-Orbitrap-HRMS plant metabolomics data, including the open-source MS-DIAL software and commercial Compound Discoverer™ software (designed for Orbitrap data processing), applied for the geographical discrimination and search for thyme markers (Spanish vs. Polish differentiation) as the case study. Both approaches showed that the feature detection process is highly affected by unknown metabolites (Levels 4–5 of identification confidence), background signals, and duplicate features that must be carefully assessed before further multivariate data analysis for reliable putative identification of markers. As a result, Compound Discoverer™ and MS-DIAL putatively annotated 52 and 115 compounds at Level 2, respectively. Further multivariate data analysis allowed the identification of differential compounds, showing that the putative identification of markers, especially in challenging untargeted analysis, heavily depends on the data processing parameters, including available databases used during compound annotation. Overall, this method comparison pointed out both approaches as good options for untargeted analysis of GC-Orbitrap-HRMS data, and it is presented as a useful guide for users to implement these data processing approaches in food authenticity applications depending on their availability. [ABSTRACT FROM AUTHOR]

This research presents an exergy analysis of a gas turbine power plant situated in Assiut, Egypt, operating under high-temperature conditions. The aim of the study is to assess the performance of the simple gas turbine cycle and identify the sources of thermodynamic inefficiencies using the second law of thermodynamics as a basis for analysis. To accomplish this, a model was developed in EES software utilizing real operational data obtained from the plant's control system. The investigation focused on the impact of varying ambient temperature on the exergy efficiency, exergy destruction, and net power output of the cycle. The results revealed that the combustion chamber accounted for the highest exergy destruction, amounting to 85.22%. This was followed by the compressor at 8.42% and the turbine at 6.36%. The overall energy and exergy efficiencies of the system were determined to be 28.8% and 27.17%, respectively. Furthermore, the study examined the effects of increasing ambient temperature from 0 to 45°C on the system's performance. It was observed that as the temperature rose, the overall exergy efficiency decreased from 27.91 to 26.63%. Simultaneously, the total exergy destruction increased from 126,407 to 138,135 kW. Additionally, the net power output exhibited a decline from 88,084 to 84,051 kW across the same ambient temperature range. These findings highlight the significant influence of ambient temperature on the thermodynamic performance of gas turbine power plants. As temperature rises, a greater amount of exergy is lost, resulting in reduced efficiency and diminished net power output. Therefore, optimizing the design of the combustion chamber is crucial for mitigating the adverse effects of hot weather conditions. The insights obtained from this study can be utilized to enhance the design and operation of gas turbine plants operating in hot climates. [ABSTRACT FROM AUTHOR]

A method was developed to analytically distinguish between the ventilated (v) and nonventilated (nv) fractions of water‐soluble ions in deposits of particle indoors. The indicative method was based on low‐cost passive outdoor and indoor sampling of the particle and ion deposits and NO2 gas and analysis of the regression values and residuals of the correlations between these parameters. The method was applied to measurements in the Pieskowa Skała Castle Museum in Poland. A dominating source of "soil and building dust" was indicated all year round, probably partly from renovation works of the castle, with larger total infiltration in the winter–spring (W‐S) but with a higher proportion of ventilation ingress in the summer–autumn (S‐A). About 60%–80%, by mass, of the water‐soluble ions in the soil and building dust were calcium and probably some magnesium bicarbonate (Ca(HCO3)2, Mg(HCO3)2) and about 10%–20% sulfates (SO4−−) with calcium (Ca++) and several other cations. The other main source of the ion deposits was indicated to be air pollution, with chloride (Cl−), sulfate (SO4−−), and nitrate (NO3−), from outdoor combustion sources, like traffic, residential heating, and industry. These were mainly v from outdoors in the colder parts of the year, but also to the more open locations in the S‐A. A small source of nv sulfate (SO4−−) was identified inside two showcases in the S‐A. The study showed good enclosure protection of the museum objects against exposure to particle pollution, but also the need to avoid the trapping of particle pollution inside showcases or closed rooms. The identification of the probable different amounts and sources of v and nv ions in the castle aided preventive actions to reduce the pollution exposure. [ABSTRACT FROM AUTHOR]

Frequent sauna bathing and higher cardiorespiratory fitness (CRF) levels may play a role in reducing the risk of mental disorders such as psychosis, however, data on their joint contributions is scanty. We aimed to investigate the interplay between sauna bathing, CRF and psychosis risk using a population-based prospective study. Self-reported frequency of sauna bathing (FSB) and CRF measured by respiratory gas analyses were assessed at baseline in 2221 men aged 42–61 years who had no history of psychosis. Frequency of sauna bathing was categorized as low and high (≤2 and 3–7 sessions/week, respectively) and CRF as tertiles (low, medium and high). Hazard ratios (HRs) with 95% CIs were estimated. During a median follow-up of 25.2 years, 215 psychotic disorders were recorded. Comparing high vs low FSB, the multivariable-adjusted HRs (95% CIs) for psychosis was 0.49 (0.32–0.74), which persisted on further adjustment for CRF 0.50 (0.33–0.75). Compared to low CRF, the multivariable-adjusted HRs (95% CIs) for medium and high CRF levels were 0.65 (0.46–0.90) and 0.75 (0.52–1.07) respectively. Compared to low FSB & low CRF, the HRs (95% CIs) for low FSB & medium-high CRF, high FSB & low CRF, and high FSB & medium-high CRF were 0.62 (0.45–0.84), 0.26 (0.11–0.60), and 0.41 (0.25–0.68) respectively. Frequent sauna baths and medium-high CRF levels appear to each independently decrease psychosis risk. However, frequent sauna bathing may be related to a reduced risk of psychosis irrespective of fitness levels and might be a stronger risk indicator for psychosis than CRF. [ABSTRACT FROM AUTHOR]

Transformers are fundamental and among the most expensive electrical devices in any power transmission and distribution system. Therefore, it is essential to implement powerful maintenance methods to monitor and predict their condition. Due to its many advantages—such as early detection, accurate diagnosis, cost reduction, and rapid response time—dissolved gas analysis (DGA) is regarded as one of the most effective ways to assess a transformer's condition. In this contribution, we propose a new probabilistic hierarchical intelligent system consisting of five subnetworks of the radial basis functions (RBF) type. Indeed, hierarchical classification minimizes the complexity of the discrimination task by employing a divide-and-conquer strategy, effectively addressing the issue of unbalanced data (a significant disparity between the categories to be predicted). This approach contributes to a more precise and sophisticated diagnosis of transformers. The first subnetwork detects the presence or absence of defects, separating defective samples from healthy ones. The second subnetwork further classifies the defective samples into three categories: electrical, thermal, and cellulosic decomposition. The samples in these categories are then precisely assigned to their respective subcategories by the third, fourth, and fifth subnetworks. To optimize the hyperparameters of the five models, the Linde–Buzo–Gray algorithm is implemented to reduce the number of centers (radial functions) in each subnetwork. Subsequently, a single-layer perceptron is trained to determine the optimal synaptic weights, which connect the intermediate layer to the output layer. The results obtained with our proposed system surpass those achieved with another implemented alternative (a single RBF), with an average sensitivity percentage as high as 96.85%. This superiority is validated by a Student's t-test, showing a significant difference greater than 5% (p-value < 0.001). These findings demonstrate and highlight the relevance of the proposed hierarchical configuration. [ABSTRACT FROM AUTHOR]

This article spotlights the interest in using co-localized infrared (IR)–Raman spectroscopy as an innovative approach for the in situ monitoring of complex gas mixtures, e.g., hydrogen (H2), nitrogen (N2), carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4), at elevated pressures. Thus, by combining the IR and Raman spectra of CH4, we proposed a new methodology for the calibration of the Raman spectra to circumvent the fact that Raman intensities are arbitrary (laser power, instrument response, integration time, and fluorescence). Applying our methodology to scale several consecutive experiments, the concentrations of all gases were determined with a relative uncertainty lower than 10%. These original results highlight the interest in co-localized IR–Raman spectroscopy analysis in a single cell for the quantitative analysis of solutes by Raman spectroscopy without the use of an internal standard. [ABSTRACT FROM AUTHOR]

The water vapor in the ambient air affects the accuracy of the photoacoustic (PA) dissolved gas analysis system for transformer health monitoring. A laser PA system was evaluated by dry and humidified standard gases to study the influence of water vapor concentration on PA gas detection. Theoretical analysis was conducted on the effect of gas molecule relaxation on PA signal detection. A high‐frequency resonant PA cell and a low‐frequency nonresonant PA cell were used to detect acetylene (C2H2) and carbon monoxide (CO), respectively. The experimental results show that the PA signal of humidified CO is about 12 times higher than PA signal of dry gas for the resonant PA detection system, respectively. In addition, as the frequency is increased from 30 to 980 Hz, the PA signals of humidified and dry CO attenuate by 1.5 and 6.9 times, respectively. [ABSTRACT FROM AUTHOR]