Volumetric Method Research Articles

Studies to estimate oil reserves using the volumetric method for the development of Turkmenistan's fields

Studies to estimate oil reserves using the volumetric method for the development of Turkmenistan's fields

Pneumatization pattern of the temporal bone with volumetric assessment and its impact on the frequency of cerebrospinal fluid leak in patients undergoing vestibular schwannoma surgery via the retrosigmoid approach

IntroductionVestibular schwannomas are benign tumors that account for 8% of all intracranial tumors. Due to their location in the cerebellopontine angle and internal auditory canal, access to these lesions requires disruption of the temporal bone. The pneumatization of this bone varies between individuals, and literature reports suggest that it may influence the frequency of cerebrospinal fluid leaks. In our study, we assessed whether the pneumatization of the temporal bone differs in individuals with or without cerebrospinal fluid leak.MethodsWe conducted a retrospective analysis that initially included 143 individuals, of whom 103 were ultimately qualified for the study. We analyzed the clinical data of the patients and the radiological characteristics of the pneumatization of the temporal bone using volumetric methods, additionally relying on classifications of temporal bone pneumatization.ResultsPneumatization of the temporal bone in patients operated on for vestibular schwannoma with cerebrospinal fluid leakage was significantly higher compared to the group without leakage (Right: 11.15 [IQR 8.93–12.83] vs. 13.25 [IQR 10.15–15.53]; p = 0.040; Left: 10.95 [IQR 9.5–12.26] vs. 14.4 [IQR 13.03–15.7]; p = 0.012). Additionally, a higher degree of pneumatization of the petrous apex was significantly more frequent in the group with cerebrospinal fluid leak in both left (p < 0.001) and right (p < 0.001) side.DiscussionThe analyzed data suggest that greater pneumatization of the temporal bone and a higher degree of petrous apex pneumatization in the classification of temporal bone pneumatization may be associated with an increased risk of cerebrospinal fluid leak. To draw causal inferences, prospective studies in this area are necessary.

Echocardiographic Evaluation of Chronic Aortic Regurgitation: Comparison With Cardiac Magnetic Resonance and Implications for Guideline Recommendations.

Guidelines for echocardiographic evaluation of aortic regurgitation (AR) have not been validated against an independent quantitative standard. The aim of this study was to evaluate the accuracy of the ASE (American Society of Echocardiography) AR guidelines against cardiac magnetic resonance (CMR) and to develop simplified approaches for detection of significant AR. Patients with AR underwent echocardiography and CMR<4 hours apart. AR severity was graded according to ASE guidelines. Quantitation of regurgitant volume (RegV) was performed with pulsed Doppler at the mitral annulus and right ventricular outflow compared with left ventricular (LV) outflow, and with proximal isovelocity surface area. The authors studied 81 patients; median age was 52 years, and 58% had a bicuspid aortic valve. According to echo, 35 (43%) patients had mild AR, 18 (22%) moderate, 12 (15%) moderate to severe, and 16 (20%) had severe AR. The area under the curve (AUC) for detection of severe AR by CMR using ASE grading was 0.9 (82.4% sensitivity and 96.9% specificity). Feasibility of RegV quantitation was >88% using either echo volumetric method, and it was low for proximal isovelocity surface area (37%). The highest accuracy for echo parameters against CMR was seen with vena contracta width, jet width, and LV end-diastolic volume index (AUC: 0.86-0.89); pressure half-time had the lowest accuracy. Without RegV quantitation, a vena contracta width≥0.5cm and indexed LV end-diastolic volume≥82mL/m2 had 95.5% positive predictive value and 87.5% negative predictive value for identifying≥moderate to severe AR by CMR (AUC: 0.89). The ASE guidelines display very good performance in identifying significant AR. A simplified approach using vena contracta width and LV volumes can be used to reliably identify significant AR. Further validation of the findings in larger cohorts and against clinical outcomes is needed.

Molecular interaction studies of Gamma-aminobutyric acid (GABA) in an aqueous medium at various temperatures: A comprehensive analysis using volumetric, thermoacoustic and DFT methods

The interaction of Gamma-aminobutyric acid (GABA) in an aqueous medium at various concentrations (0.101–1.086) mol·kg−1 as a function of temperature is being studied using volumetric, viscosity and acoustic analysis. The calculation of apparent molar volume (VΦ), partial molar volume (V∅o), apparent molar isentropic compression (Kϕ) and partial molar isentropic compression (Kϕ0) of GABA in an aqueous medium has been done by measuring the densities and speed of the sound in the temperature range of 298.15–323.15 K. The thermo-acoustic parameters like adiabatic compressibility (βs), acoustic impedance (Z), intermolecular free length (Lf), relative association (RA), relaxation time (τ), internal pressure (πi), enthalpy (ΔH), Gibbs free energy (ΔG), and change in entropy (ΔS) are also computed. The strength of the hydrogen bond interaction of GABA in an aqueous medium and its dipole moment are calculated using single-point energy calculations. These calculations employ IEFPCM and PCM solvation models using DFT/B3LYP and MP2 methods with the 6-311G++ (d, p) basis set. The outcomes are interpreted in terms of hydrogen bond interactions that exist in the mixture.

Comparison of Conventional and Microwave Heating

Carnot batteries (or Power-to-Heat-to-Power systems) are capable of increasing the use of electricity from photovoltaic or wind power plants to achieve decarbonisation of the electricity sector. To decouple electricity production from demand, these renewable power plants can be connected to the thermal energy storage system of a concentrated solar thermal power plant via electric heaters. As an alternative to electric heaters, microwaves are studied as a volumetric and selective heating method, avoiding the limitations of the Joule effect conventional heating when having solar salt (non-eutectic mixture of 60 wt % NaNO3 and 40 wt % KNO3), which is a storage medium with low thermal conductivity, working at a temperature very close to its affordable maximum temperature without degradation. In this work, the two heating methods are compared both experimentally and numerically. At experimental level, a microwave oven and a muffle furnace are used to record energy consumption and time for a common objective. Additionally, different crucible materials were used to test their suitability with microwaves. Only quartz glass was validated for microwave heating, while the porcelain and alumina based materials (Corundum and Alsint 99.7) failed while exposed to microwaves. Compared to conventional heating, heating solar salt with microwaves saved fifty minutes of time and ninety percent of consumption. These experiments were validated by numerical simulations, showing a different distribution in each experiment.

Prediction of Malignancy and Pathological Types of Solid Lung Nodules on CT Scans Using a Volumetric SWIN Transformer.

Lung adenocarcinoma and squamous cell carcinoma are the two most common pathological lung cancer subtypes. Accurate diagnosis and pathological subtyping are crucial for lung cancer treatment. Solitary solid lung nodules with lobulation and spiculation signs are often indicative of lung cancer; however, in some cases, postoperative pathology finds benign solid lung nodules. It is critical to accurately identify solid lung nodules with lobulation and spiculation signs before surgery; however, traditional diagnostic imaging is prone to misdiagnosis, and studies on artificial intelligence-assisted diagnosis are few. Therefore, we introduce a volumetric SWIN Transformer-based method. It is a multi-scale, multi-task, and highly interpretable model for distinguishing between benign solid lung nodules with lobulation and spiculation signs, lung adenocarcinomas, and lung squamous cell carcinoma. The technique's effectiveness was improved by using 3-dimensional (3D) computed tomography (CT) images instead of conventional 2-dimensional (2D) images to combine as much information as possible. The model was trained using 352 of the 441 CT image sequences and validated using the rest. The experimental results showed that our model could accurately differentiate between benign lung nodules with lobulation and spiculation signs, lung adenocarcinoma, and squamous cell carcinoma. On the test set, our model achieves an accuracy of 0.9888, precision of 0.9892, recall of 0.9888, and an F1-score of 0.9888, along with a class activation mapping (CAM) visualization of the 3D model. Consequently, our method could be used as a preoperative tool to assist in diagnosing solitary solid lung nodules with lobulation and spiculation signs accurately and provide a theoretical basis for developing appropriate clinical diagnosis and treatment plans for the patients.

Phase field numerical strategies for positive volumetric strain energy fractures

AbstractA reasonable crack driving force is the key to preventing compression cracks and eliminating unrealistic crack propagation in phase field fracture analysis. Thus, examining the roles of volumetric strain energy (VSE) and deviatoric strain energy (DSE) in influencing crack propagation is necessary. This paper presents a comprehensive analysis of the following four different approaches to energy decomposition‐driven crack propagation: the positive volumetric strain energy method (VSEM), deviatoric strain energy method (DSEM), volumetric‐deviatoric strain energy method (VDSEM), and no decomposition method (NM). All of the strain energy is involved in the development of the crack propagation. The following four examples are investigated: two benchmark single‐side notched examples, a complex crack containing a hole example, and a crack coalescence in an asymmetric double notch example. The VSEM's numerical findings align with literature and experimental observations, confirming that positive VSE rather than DSE promotes crack propagation.

Searching of optimal conditions and development of analysis of isocyanate groups in prepolymers

The purpose of the work was to study the options for volumetric analysis of isocyanate groups in prepolymers and to search for factors affecting the accuracy of the analysis in order to identify differences between the values specified by the manufacturer and those obtained in the laboratory.Metods. Intermediate polymerization products based on isocyanates from two or more monomeric units used for the production of polyurethanes, the quality of which is determined by the optimal ratio of isocyanate and hydroxyl groups, were selected as the object of research. The NCO index was determined by the volumetric method based on the interaction of isocyanate groups with diethylamine, with confirmation of the results by methods of mathematical statistics.Results. the work analyzes currently known methods for determining the content of isocyanate groups in prepolymers and identifies differences in the technique of execution. A volumetric method for determining the NCO index based on the interaction of isocyanate groups with diethylamine was used. The solubility of industrial prepolymer samples was evaluated and the dissolution rate was calculated, on the basis of which the optimal volume of the solution and prepolymer samples were determined, providing an accurate determination of the isocyanate number. The adjusted conditions allowed us to reach the required value of the NCO index of the SKU prepolymer, calculated on the basis of static processing of the results and the construction of the Gauss distribution curve. Changes in the methodology make it possible to reach a certified value of the indicator, which allows its use for further calculations in the synthesis of polyurethane.Conclusion. Recommendations for determining the isocyanate index for the analysis of prepolymer by the volumetric method will help to monitor incoming raw materials for compliance with certificates to perform an accurate calculation of raw materials in the synthesis of polyurethane.Key words: prepolymer, polyurethane, isocyanate index, volumetric analysis, diethylamine, solubility.

Tuning of Particle Size of Zeolitic Imidazolate Framework-7 via Rapid Synthesis Duration for CH4 Adsorption

In this work, zeolite imidazolate framework-7 (ZIF-7) nanoparticles are synthesized via a solvothermal method and rapid synthesis durations of 1 h and 3 h. The effect of the synthesis duration on the structural properties of ZIF-7 was characterized by XRD and FESEM analyses. Subsequently, CH4 single gas adsorption over ZIF-7 nanoparticles was examined using the volumetric method at room temperature and pressure ranging from 2 to 9 bar. The results showed that the synthesized ZIF-7 adsorbents were highly crystalline with a well-defined and homogeneous particle size distribution of 50–60 nm. It was found that increasing the synthesis duration from 1 h to 3 h did not amend the structure and morphology of the resultant samples significantly, mainly due to the short synthesis duration. Meanwhile, the CH4 adsorbed by ZIF-7 nanoparticles increased with rising pressure for both samples, and the ZIF-7 nanoparticles synthesized at 3 h showed a greater adsorption capacity than that of 1 h, mainly due to its higher crystallinity and well-developed pore structure. The ZIF-7 synthesized at 3 h demonstrated an adsorption capacity up to 2.2 mol/kg, which was higher than those values reported in the literature for micron-sized ZIF-7 samples. The CH4 gas adsorption behavior of ZIF-7 nanoparticles synthesized at 1 h and 3 h were well predicted by the Langmuir isotherm model, with coefficients of determination, R2, of 0.9994 and 0.9982, respectively.

Insights from volumetric, acoustic, conductance and spectroscopic studies to study the molecular interactions of drug Levocetirizine in aqueous and aqueous glucose solutions at varying temperatures

Levocetirizine, an antihistamine, has been analyzed in relation to temperature by volumetric, acoustic, and spectroscopic methods to investigate its interaction with glucose, the predominant carbohydrate. Density and ultrasonic velocity for LC (0–0.10 mol dm−3) at different temperature (298.15, 308.15 and 318.15 K) in water and in aqueous solution of glucose (0.05, 0.10 and 0.15 mol kg−1) have been recorded using Anton Paar DSA 5000 M. The apparent molar volume (Vϕ), limiting apparent molar volume (Vϕ0), apparent molar compressibility (Kϕ,S), limiting apparent molar compressibility (Kϕ,S0) were computed utilizing the experimental data. In addition, the transfer parameters of LC from water to aqueous glucose solutions were identified and elucidated using the co-sphere model. The transfer volumes have been utilized to estimate the interaction coefficients. Limiting apparent molar expansibility (ϕE0) and Hepler’s constant was obtained to throw light upon the structure-making or structure-breaking effect of solute. Multiple acoustical parameters like isentropic compressibility (KS), relaxation strength (r), intermolecular free length (Lf), specific acoustic impedance (Z), Wada’s constant (W), relative association (RA), Rao’s constant (Rm), molar volume (Vm), Van der Waals constant (b), and free volume (Vf) were determined to validate the thermodynamic results.

Effect of some design parameters on the performance of side access nozzle and grooved plate of centre pivot sprinkler

This research evaluates the effect of various heights, pressures, nozzle size and groove numbers on the uniformity distribution of a developed pivot sprinkler. The experiment was set up at an open space in Niger State College of Agriculture Mokwa. The wind speed and temperature during the experiment were at an average of 2.2mph and 25°C. A nozzle of size 6mm, and deflection plate of 6 curved grooves were used in a centre pivot spray unit. In evaluating the performance of the spray unit components i.e. the nozzle and deflection plate, three different pressures of 5, 10, and 15 Psi and heights of 1, 1.2, and 1.5mm were used. The support structure for the experiment is an inverted U-shaped frame designed to support a spray sprinkler at different heights. The water source was a reservoir with a capacity of 3m3and a 1.5hp electric centrifugal pump was used. The volumetric or bucket method was used to measure flow rate. The application rate was measured using catch can method. The duration of each test was approximately 30min. The data obtained from the measurements were statistically analyzed with line graphs using Excel. Relationships were also established between discharge and pressure. The highest index of jet break up was 4.89 at 15Psi and 3.74 at 10Psi. The result shows that as the pressure increases with height the CU also increases. The highest uniformity of 79.4% was obtained at 1.5m height and 15Psi.

Дослідження впливу природної та штучної пасивації на швидкість корозії магнієвого сплаву для хірургічних імплантатів

Magnesium-based alloys are widely used materials for surgical implants. Considerable efforts of researchers are applied to the development of new magnesium alloys and methods of their surface treatment in order to protect against biocorrosion or to regulate its speed. The idea of the work is to determine the potential of known magnesium alloys as materials for the production of implants. Industrial magnesium based alloys were analyzed from the point of view of suitability for use for surgical biodissolvable implants. It is shown that the ML10 alloy is the most suitable as it does not contain toxic components, namely aluminum, nickel and cadmium. Samples for corrosion tests were made from a billet of ML10 alloy after processing by plastic deformation by pressing through a calibrated die at a temperature of 375 ± 20 °С. Together with the ML10 alloy, comparative studies of the ML5 alloy were conducted. Corrosion tests of ML5 and ML10 alloys without a coating, as well as of the ML10 alloy with a coating applied by the micro-arc oxidation (MAO) method for 30 seconds, were carried out using the volumetric method. The samples were kept in a 3% NaCl solution at a temperature of 38 ± 2 °C. The corrosion rate of the ML5 alloy was at a constant level during the experiment. No significant ability of the ML5 alloy to self-passivate was found. The ML10 alloy turned out to be capable of significant self-passivation under the influence of a corrosive environment. During the experiment, the corrosion rate of the ML10 alloy sample decreased approximately ten times. It was also established that the corrosion rate of ML10 alloy samples with MAO coating was approximately three times lower than that of samples of the same alloy without coating. Preliminary information was obtained on the reduction of the corrosion rate of the ML10 alloy after plastic deformation. Further research can be aimed at confirming this phenomenon, determining its causes, as well as establishing quantitative indicators of the influence of the degree of plastic deformation on the corrosion rate of the ML10 alloy. Keywords: surgical implants, magnesium alloys, corrosion, self-passivation, coating.

Airborne Alternaria Spores: 70 Annual Records in Northwestern Spain.

This study presents data on the concentration of Alternaria spores in the atmosphere of the northwestern Iberian Peninsula. A non-viable volumetric method was used to collect the samples, resulting in a database of 70 annual. When the annual averages for each locality are calculated, Ourense stands out with 2152 spores/m3, followed by Vigo and Lugo, while Santiago de Compostela recorded the lowest concentrations. Focusing on the total data for each locality, the main sporulation period started in May and ended in October in all localities, centered on a single phase, with an earlier onset and longer duration in Ourense and Vigo. The number of days with concentrations in excess of 100 spores/m3 was very low in Santiago de Compostela, Ourense, and Vigo and null in Lugo. Temperature was the meteorological parameter for which the highest statistical correlation was obtained in all locations, being favorable to the concentration of spores in the air. Temperature ranges favorable to the presence of airborne spores in the study area ranged from 25.5 to 31.2 °C. Based on the analysis of the data collected, it is concluded that Alternaria spore concentrations are low throughout most of the year.

Observed and expected reliability of echocardiographic volumetric methods and critical change values for quantification of mitral regurgitant fraction in dogs.

Reliability of echocardiographic calculations for stroke volume and mitral regurgitant fraction (RFMR) are affected by observer variability and lack of a gold standard. Variability is used to calculate critical change values (CCVs) that are thresholds representing real change in a measure not associated with observer variability. Observed intra- and interobserver accuracy and variability in healthy dogs help model CCV for RFMR. Reliability cohort of 34 healthy dogs; allometric scaling cohort of 99 dogs with heart disease and 25 healthy dogs. Accuracy, variability, and CCV of 2 observers using geometric and flow-based echocardiography were prospectively compared against a standard of RFMR = 0% and extrapolated across a range of expected RFMR values in the reliability cohort partly derived from cardiac dimensions predicted by the allometric cohort. Accuracy of methods to determine RFMR in descending order was 4-chamber bullet (Bullet4CH), mitral inflow, cube formula, and Simpson's method of disks. Intraobserver variability was relatively high. The CCV for RFMR ranged from 28% to 88% and was inversely related to RFMR when extrapolated for use in affected dogs. For both observers, the Bullet4CH method had the lowest intraobserver CCV (Operator 1:28%, Operator 2:41%). Interobserver strength of agreement was low with intraclass correlation coefficients ranging from 0.210 to 0.413. Echocardiographic volumetric methods used to calculate stroke volume and RFMR have low accuracy and high variability in healthy dogs. Extrapolation of observed CCV to a range of expected RFMR suggests observers and methods are not interchangeable and variability might hinder routine clinical usage. Individual observers should be aware of their own variability and CCV.

Evaluation of the measurement uncertainty during the calibration of metal reference gauges of the 2nd category

The paper considers problematic issues related to ensuring the uniformity of measurements in the field of legal metrology, namely, during the calibration of working measurement standards used for verification of legally regulated measuring instruments. One of the conditions for ensuring the uniformity of measurements is the compliance of any measuring instrument with the requirements that are prescribed in its technical specification, where standardized metrological characteristics are indicated, which allows us to conclude about the suitability of the instrument for measurements in a known range and with a known accuracy. The procedure for verification of legally regulated measuring instruments establishes a ratio between the expanded measurement uncertainty provided for by the measurement standard and the maximum permissible error of the measuring instruments of no more than one to three. Determining such a ratio is an example of indirect accounting for the measurement uncertainty. The reliability of the assessment of the compliance of a working measurement standard with metrological requirements, which are regulated by the technical specification, depends on the correctness of the procedures for evaluating the measurement uncertainty during calibrations. The paper indicates the problems of updating the existing regulatory framework for the calibration of measuring instruments using reference gauges as an example and ensuring metrological traceability of the results of the calibration of the liquid volume measuring equipment. Attention was drawn to the need to apply in Ukraine the international practice of the standardization of calibration techniques and methods of uncertainty evaluation to ensure the uniformity of measurements. A procedure for evaluating the measurement uncertainty during the calibration of the reference 2nd-grade gauge by the volumetric method, which is used as a working measurement standard when verifying legally regulated measuring instruments – fuel dispensers for refuelling cars – is proposed.

Image response-assisted volumetric reconstruction for simultaneous multi-color light-field microscopy

Light-field microscopy enables real-time volumetric imaging, offering substantial advantages for real-time fluorescence imaging. However, when applied to multi-color imaging, positional cross-talk between different fluorescent signals in the object space reduces reconstruction accuracy. Additionally, imaging each color through sequential excitation of fluorophores significantly compromises imaging speed. In this paper, an image response-assisted volumetric reconstruction method that unmixes multi-color fluorescence light-field images using pixel support derived from the light-field imaging response is proposed. This approach enables simultaneous multi-color imaging with significantly improved volumetric reconstruction accuracy. The correctness and effectiveness of the proposed method are validated through both simulations and experiments. The root-mean-square-error of multi-color volumetric reconstruction is reduced by 37.87 % on average compared with the simultaneous multi-color reconstruction methods obtained by simply combining single-pixel spectrum conversion methods and linear unmixing method in rapid-moving micro-particle observation, showcasing high accuracy simultaneous multi-color imaging performance. Volumetric imaging of motor neurons and whole-body cells of live dual-color zebrafish larvae at 20 Hz demonstrates the ability to be applied to real biomedical imaging.

Novel In-Line Hemolysis Detection on a Blood Gas Analyzer and Impact on Whole Blood Potassium Results.

Preanalytical error due to hemolyzed blood samples is a common challenge in laboratory and point-of-care (POC) settings. Whole blood potassium (K+) measurements routinely measured on blood gas analyzers are particularly susceptible to hemolysis, which poses a risk for incorrect K+ results. The GEM Premier 7000 with IQM3 (GEM 7000) blood gas analyzer provides novel integrated hemolysis detection within the sample measurement process. Therefore, the GEM 7000 can detect and flag hemolyzed whole blood samples at the POC, warning the operator of potentially erroneous results. Heparinized venous or arterial whole blood samples were used for K+ interference studies and assessed for hemolysis agreement utilizing either a traditional volumetric method or chemistry analyzer serum index measurements with the Roche cobas c311 or Abbott Alinity c. Hemolysis interference studies performed at 2 different K+ concentrations (3.8 and 5.3 mmol/L) identified that a plasma free hemoglobin ≥116 mg/dL can impact K+ results on the GEM 7000. Hemolysis agreement studies demonstrated an excellent agreement of >99% with the volumetric method, 98.8% with cobas H index, and 96.4% with Alinity H index. GEM 7000 K+ results were correctly flagged for both native and spiked samples. GEM 7000 hemolysis detection provides a novel technology to detect hemolysis in whole blood samples. Moreover, the GEM 7000 demonstrates excellent agreement with traditional laboratory hemolysis detection methods and offers an integrated technological solution for assuring the quality of whole blood K+ results in POC settings.

Methods for Measuring Organic Carbon Content in Carbonate Soils (Review)

In world practice, the measurement of the mass fraction of carbon of organic compounds (Corg) in soils containing carbonates is carried out in various ways. An analysis of methods that allow solving this problem was carried out, including the latest approaches: thermogravimetry, differential scanning calorimetry, spectroscopy. It has been shown that the presence of CaCO3 does not prevent the use of the dichromatometric method (Tyurin, Walkley-Black) for determining Corg. The disadvantages of the method boil down to the laboriousness of the analysis, the need for constant presence of the operator, incomplete oxidation of organic compounds and environmental pollution. The method of measuring soil mass loss-on-ignition (LOI) is economical and rapid, but it gives an overestimated Corg content, which is associated with the inadequacy of the conversion factor of 1.724, the presence of adsorbed and chemically bound water, as well as mineral components decomposing at T = 105–550°С. The most relevant solution for finding Corg in carbonate soils is to use an analyzer and a calcimeter, although the accuracy of Corg measurements in the presence of carbonates is significantly reduced due to the quadratic summation of the errors of the two methods. The high cost of the device, maintenance, verification and repair limit its widespread use in soil laboratories. To measure the content of soil carbonates, it is possible to use both gravimetric (LOI) and volumetric (calcimeter) methods. The use of the latter is preferable for soils with a predominance of CaCO3 in carbonate composition. Preliminary removal of carbonates from soil samples is labor-intensive and can lead to partial loss of Corg due to acid extraction. The high cost of instruments and the lack of libraries of soil spectra hinder the development of vis-NIR and MIR spectroscopy as an alternative to “wet” chemistry methods. Continuing comparative studies will improve the understanding of the spatial patterns of distribution of carbon in soil organic compounds.

Hydrogen adsorption kinetics in organic-Rich shale reservoir rocks for seasonal geological storage

The geo-storage of hydrogen (H2) is essential for advancing a robust and industrial-scale H2-based economy. The efficient H2 storage in a geological formation depends on the presence of a secure and impermeable caprock, such as a shale formation. However, the existing literature lacks information on the kinetics of H2 adsorption in actual shale formations with diverse organic contents and mineral compositions. Therefore, the kinetics of H2 adsorption in organic-rich shale samples from a Jordanian oil (JO) source rock formation are experimentally investigated herein at various temperatures (193, 273, 303, and 333 K) and two equilibrium pressures (15 and 45 bar) by using a volumetric method. The impact of mineral compositions and total organic content (TOC) on H2 adsorption is studied using two samples with distinct mineralogy and TOC values. Thermodynamic calculations are performed, and common adsorption models are used to analyze the experimental data. The results indicate that the H2 adsorption rate increases with pressure and decreases with temperature, being characterized by an initial rapid adsorption phase followed by a slower adsorption period as the uptake of H2 approaches equilibrium. More interestingly, the rate of H2 adsorption is higher in the sample with a high TOC and a richer composition of carbonate minerals. Both the applied adsorption isotherm models and adsorption kinetics models fit the experimental data remarkably well, thereby indicating their suitability for analyzing the kinetics of H2 adsorption in the JO shale. The unipore model matches the H2 kinetics data well, with R2 > 0.91. The H2 diffusion coefficient increases with pressure and temperature, where the H2 diffusion in shale accelerates with thermal motion intensity. This study provides fundamental insights into the adsorption kinetics of H2 and is expected to assist in implementing an industrial H2-based economy.

Comparison of Olea pollen sampling between gravimetric and volumetric traps (NW of Morocco)

Olea pollen is considered one of the most critical causes of respiratory allergic disease in the Mediterranean region, contributing to different symptoms in allergic sufferers. Due to the high increase in the prevalence of olive pollen caused by the expansion of cultivated areas especially in the Mediterranean region, the aim of this study was to examine the Olea pollen sampling efficiency between gravimetric and volumetric pollen traps over the period 2018–2022. Our data demonstrated that Olea pollen season start-date was generally recorded earlier with volumetric trap than shown with gravimetric method. Moreover, the peak dates occurred mainly in May for the years studied. Across the entire period, the greatest pollen concentrations were reached in the week 11th and >60 % of the total Olea pollen were already reached after the ninth week of sampling in 2020. In general, the evolution of pollen sampling for both methods demonstrates similar temporal development. Variations in the seasonal pollen integral could be attributed to the elevation above ground level at which the traps were placed, exposure to regional winds, the influence of long-range transported pollen and the mode of pollen transport. The findings indicate that the gravimetric method was equally practical as the volumetric method in estimating airborne pollen.