Fraction Of Fluid Research Articles

Mast Cell Proteases Promote Diverse Effects on the Plasminogen Activation System and Wound Healing in A549 Alveolar Epithelial Cells.

Tissue damage, epithelial alterations, and intraepithelial presence of mast cells (MCs) are characteristics of asthma pathogenesis. Increased alveolar infiltration of MC populations has also been identified as a feature of asthma and other chronic respiratory diseases. The asthma associated receptor, urokinase plasminogen activator receptor (uPAR), has been shown to regulate bronchial epithelial repair responses. However, the impact of MC tryptase and chymase on functional properties and expression of uPAR in alveolar epithelial cells have not been fully investigated. Alveolar epithelial cell migration and wound healing were investigated using holographic live cell imaging of A549 cells in a wound scratch model post stimulation with tryptase or chymase. The expression of uPAR was investigated on the protein and gene level from cellular supernatants and in bronchoalveolar lavage fluid fractions from allergic asthmatics. We found that tryptase improved wound healing capacity, cellular migration and membrane bound uPAR expression. Chymase reduced gap closure capacity, cellular migration and membrane bound uPAR expression but increased soluble uPAR release. Our data suggest a dual regulatory response from the MC proteases in events related to uPAR expression and wound healing which could be important features in asthmatic disease.

A parametric study on the efficiency of a solar evacuated tube collector using phase change materials: A transient simulation

Evacuated solar collectors are renewable systems that provide a considerable quantity of heat during test time. However, this system is unable to provide energy in the absence of sunlight. Thus, this study attempted to numerically study a Solar Evacuated Tube Collector (ETC) performance using phase change materials (PCM). PCM can store considerable thermal energy during the day and release it to the system at night. In order to simulate the ETC-PCM system, an accurate three-dimensional model considering all the layers is designed. In the present numerical investigation, the effect of various properties of the PCM, including enthalpy, melting point, and thermal conductivity, on the outputs of the ETC-PCM system are evaluated separately. Also, the effects of some other factors, such as MWCNT nanoparticles dispersion in the base fluid and working fluid mass flow rate, on the performance of the ETC-PCM system are studied. Furthermore, to evaluate the performance of the system and model the behavior of the PCM during the day, the system is simulated under the weather condition of Hing Kong from sunrise until sunset. According to the results of the simulations, a reduction in PCM melting point from 50 °C to 35 °C can elevate the efficiency of the ETC-PCM device. PCM with a high melting point remains solid during the day. Thus, its effect on the output of the system cannot be revealed. Moreover, it is found that the system using PCM with the latent heat of 160 kJ/kg has the best performance among the studied cases. Besides, it is illustrated that raising the mass flow rate of working fluid and mass fraction of nanoparticles can enhance the system's performance.

Validation of a SARS-CoV-2 RT-PCR assay: a requirement to evaluate viral contamination in human semen

Research questionIs it possible to validate an accurate and reliable method for direct detection of SARS-CoV-2 by reverse transcription polymerase chain reaction (RT-PCR) in human semen fractions? DesignThis qualitative improvement study aimed to provide a prospective validation of SARS-CoV-2 detection in male semen. The SARS-CoV-2 genome was detected by multiplex real-time RT-PCR on patient samples that underwent routine semen analyses for infertility at the Center for Reproductive Medicine at the University Hospital of Clermont-Ferrand. Samples comprised surplus semen collected for treatment with assisted reproductive technology. Seminal fluid and spermatozoa fractions were isolated with density gradient centrifugation and cryopreserved. Positive samples were prepared with a standard of inactivated SARS-CoV-2 particles. ResultsThe analytical method was validated in both seminal fluid and spermatozoa fractions. In both semen fractions, the assay was repeatable, reproducible and showed high sensitivity with a limit of detection of 0.33 SARS-CoV-2 genome copies/µl. The limit of quantification was 1 copy of the SARS-CoV-2 genome/µl. The method was effective regardless of semen quality (normal and altered sperm parameters), number of spermatozoa or the cryoprotectant media used to freeze spermatozoa. ConclusionThis validated RT-PCR assay provided accurate and reliable screening of SARS-CoV-2 in seminal fluid and spermatozoa fractions. This method is essential to ensure protection against viral contamination in the cryobanking process.

A new approach for saturation height modelling in a clastic reservoir using response surface methodology and artificial neural network

• Brook-Corey's function was the best conventional water saturation prediction model. • The RSM model gave a better prediction fit than the conventional methods. • The independent variables had an influence on water saturation via 3D response surface plots. • Mathematical links improved the RSM model's performance in design space. • The RBFNN model was superior compared to the RSM model with mathematical links. Saturation Height Modelling (SHM) is an important reservoir characterization method for estimating the water saturation component which is a fraction of the total reservoir fluids in porous media. Although several methods have been used in calculating water saturation, little or no research has employed Response Surface Methodology (RSM) in predicting water saturation in field cores. In this paper, well datasets were tested with four conventional curve fitting models including Lambda, Thomeer, Leverette J, and Brooks-Corey of which Brook-Corey gave the best fit with an R 2 of 0.485. The RSM with the Central Composite Design (CCD) was used to obtain the mathematical and statistical relationship between the predictors and target as well as the variables’ interactions optimization. The model was analysed using Analysis of Variance (ANOVA) which validated the correlations with an F-value of 4.96, a p-value less than 0.05, and a Lack of Fit-value of 0.76 implying that the model developed was statistically significant. The RSM model gave a better fit with an R 2 value of 0.817 with mathematical links, almost twice that predicted by the conventional methods. Then, the testing performance of the RSM model was compared to the standard radial basis function neural network model ( R 2 of 0.9779). The results proved that both RSM and RBFNN models’ performance was accurate and reliable and could give a precise prediction of water saturation without any conventional curve fitting parameters.

Tungsten isotopic fractionation at the Mariana arc and constraints on the redox conditions of subduction zone fluids

Fluid release from subducting slabs during recycling of oceanic lithosphere plays an important role in concentrating select elements near the Earth’s surface. Yet the extent to which these fluids are oxidising or reducing (fO2), one of the key characteristics that controls element mobility, remains poorly understood. Additionally, it is unclear whether the fO2 signature of arc fluids is generated deep within the slab during subduction or if it reflects later, shallower subarc crustal processes. Previous experimental work has shown that the extent to which highly incompatible W partitions into aqueous fluids depends on the temperature and fO2 conditions of the fluids. In the subducting slab, W partitions into rutile with a different coordination number to that which it exhibits in fluids, a process which may generate stable W isotopic fractionation. Therefore, if the competition between partitioning into aqueous fluids versus rutile is controlled by the conditions within the subducting slab, the elemental and stable W isotopic systematics of arc lavas may provide a novel tool with which to investigate subduction zones. We present isotopic compositions of a well characterised suite of arc lavas from the central island province of the Mariana arc (W. Pacific), and rutile separates from exhumed fragments of subducted, depleted, mafic oceanic crust from the Raspas Complex, Ecuador. Our data show that lavas from Guguan that exhibit the strongest geochemical signature of subduction zone fluids (e.g., high Ba/Th, Mo/Ce, Pb/Ce), contain the highest abundances of W compared to similarly magmatically incompatible Th, in agreement with anticipated fluid mobile behaviour. These Guguan lavas have distinct, heavy stable W isotopic compositions (δ186/184W = +0.134 to +0.156 ‰) compared to MORB (δ186/184W = +0.078 to +0.099 ‰) and those from sediments-dominated islands like Uracas and Agrigan (δ186/184W = +0.080 to +0.111 ‰). The W isotopic compositions of sediments off-board the Mariana arc are more variable, with the volcaniclastic sediments having δ186/184W values closest to those of the sediment dominated arc lavas. We show that rutile from representative subducting mafic crust incorporates isotopically light W, consistent with a coordination change from tetrahedral in fluids and melts to octahedral in the structure of rutile. We suggest that isotopically heavy fluids, complementary to the residual rutile in the mafic crust, account for the high δ186/184W of the fluid-dominated Guguan lavas, a process previously invoked to control Mo systematics in the same samples. Combining our new elemental and isotopic W data with these existing Mo data, we model the influence of oxygen fugacity on fluid compositions in equilibrium with the mafic crust, and the fraction of such fluids required to be added to the mantle wedge to reproduce the Mo-W systematics of erupted arc lavas. Our models show that more fluid is required (F = 6 %) than can be generated internally in the mafic oceanic crust, and that this fluid must be oxidised, perhaps as high as FMQ +5. We suggest that these requirements document the interaction of subducted mafic crust with an external source of oxidising fluids sourced from dehydration of underlying serpentinites.

Viscous to Inertial Transition in Dense Granular Suspension.

Granular suspensions present a transition from a Newtonian rheology in the Stokes limit to a Bagnoldian rheology when inertia is increased. A custom rheometer that can be run in a pressure- or a volume-imposed mode is used to examine this transition in the dense regime close to jamming. By varying systematically the interstitial fluid, shear rate, and packing fraction in volume-imposed measurements, we show that the transition takes place at a Stokes number of 10 independent of the packing fraction. Using pressure-imposed rheometry, we investigate whether the inertial and viscous regimes can be unified as a function of a single dimensionless number based on stress additivity.

Macro-mechanical properties of magnetorheological fluids based on body-centered cubic structure

This paper addresses the problem that the microstructure model of magnetorheological fluid established by traditional single-chain or multi-chain dense rows is unable to accurately describe the rheological behavior and the sudden change of macroscopic mechanical properties under the action of an applied magnetic field, and analyzes the stable cluster-like structure formed by a specific volume fraction of magnetorheological fluids in a micro-narrow channel under the action of external magnetic field and extrusion pressure. This paper also establishes the equations of motion and dynamics of magnetic particles under the action of external magnetic field, analyzes the dynamic evolution of particle microstructure, performs numerical simulations of two-dimensional chaining using Matlab, and establishes a microscopic observation test bench for comparison and verification; and it establishes a model of complex cluster-like structure of magnetorheological fluids body-centered cubic, and analyzes the system energy, stability and force of the body-centered cubic structure based on the minimum system energy theory and Hertzian contact theory; and further establishes a shear yield stress model based on the body-centered cubic microstructure to analyze the macroscopic mechanical properties of magnetorheological fluids, thereby enriching the theoretical system of extrusion strengthening of magnetorheological fluids in the microscale.

Impact of data processing and robust machine learning process on accurate estimation of specific heat capacity property in energy storage applications

The specific heat capacity propery is a critical thermal property because it is directly related to heat storage and transfer. The need for better and novel thermal energy storage materials have led to the discovery of high temperature nanofluids with molten salts (nanosalts). The utilization of novel machine learning tools in accurately estimating the specific heat capacity of nanofluids, would further pave the way for more innovative studies on nanosalt, hence the prediction of specific heat capacity of hybrid nanofluids constitute a significant research area. Despite the few researches conducted in the area of prediction of these fluids, priority with regards to the robust analysis of input variables for different machine learning algorithms have not been given due consideration. Therefore, this present study aims to develop and validate a robust package of machine learning algorithms (twenty machine learning algorithms) in estimating the specific heat capacity of hybrid nanofluids, across different feature spaces. The different algorithm hyperparameters were adjusted to give optimum prediction. A total of 600 data points were retrieved and split into training, testing, and validation data set, for which the validation dataset was not used in the training and testing process. The input variables used in the training of the machine learning models are temperature, volume fraction, the specific heat capacity of the base fluid, the specific heat capacity of individual nanoparticles, and the mixture ratio of individual nanoparticles. The Model A, which constituted the seven (7) input variables gave the best prediction accuracy with validation score of 0.999703, while the Model C, which contained the feature variables of temperature, volume fraction and specific heat capacity of the base fluid gave the least prediction accuracy. The optimal machine algorithms retrieved for the Model A, B, C and D was the Ridge, Gradient Boost regressor, Passive Aggressive regressor, and Kernel ridge regressor. The combination of ensemble tree regressors and online learning algorithms can be coded and used in future prediction analysis of SHC, as they have both shown accurate prediction quality.

Brain Delivery of IGF1R5, a Single-Domain Antibody Targeting Insulin-like Growth Factor-1 Receptor.

The ability of drugs and therapeutic antibodies to reach central nervous system (CNS) targets is greatly diminished by the blood–brain barrier (BBB). Receptor-mediated transcytosis (RMT), which is responsible for the transport of natural protein ligands across the BBB, was identified as a way to increase drug delivery to the brain. In this study, we characterized IGF1R5, which is a single-domain antibody (sdAb) that binds to insulin-like growth factor-1 receptor (IGF1R) at the BBB, as a ligand that triggers RMT and could deliver cargo molecules that otherwise do not cross the BBB. Surface plasmon resonance binding analyses demonstrated the species cross-reactivity of IGF1R5 toward IGF1R from multiple species. To overcome the short serum half-life of sdAbs, we fused IGF1R5 to the human (hFc) or mouse Fc domain (mFc). IGF1R5 in both N- and C-terminal mFc fusion showed enhanced transmigration across a rat BBB model (SV-ARBEC) in vitro. Increased levels of hFc-IGF1R5 in the cerebrospinal fluid and vessel-depleted brain parenchyma fractions further confirmed the ability of IGF1R5 to cross the BBB in vivo. We next tested whether this carrier was able to ferry a pharmacologically active payload across the BBB by measuring the hypothermic and analgesic properties of neurotensin and galanin, respectively. The fusion of IGF1R5-hFc to neurotensin induced a dose-dependent reduction in the core temperature. The reversal of hyperalgesia by galanin that was chemically linked to IGF1R5-mFc was demonstrated using the Hargreaves model of inflammatory pain. Taken together, our results provided a proof of concept that appropriate antibodies, such as IGF1R5 against IGF1R, are suitable as RMT carriers for the delivery of therapeutic cargos for CNS applications.

Numerical Modeling and a Parametric Study of Various Mass Flows Based on a Multi-Phase Computational Framework

Gravity-driven mass flows are typically large-scale complex multi-phase phenomena involving multiple interacting phases. Various types of mass flows usually exhibit distinct behaviors in their formation, propagation and deposition. In such large-scale geological systems, many uncertainties may arise from the variations in material composition and phase behavior. The present study aims to investigate the important characteristics of some common types of mass flows including debris flows, mudflows and earth flows, based on a recently developed multi-phase computational framework, r.avaflow for flow simulation. Fractions of different phases are varied to reflect different characteristics of material composition of various mass flows and simulate the resulting flow behavior. The evolution of the critical entities during the flow motion, such as velocity, peak discharge, flow height, kinetic energy, run-out distance and deposition is examined; considerable differences among various flows are identified and discussed. Overall, the simulated mudflow cases develop higher velocity, peak discharge, kinetic energy, and longer run-out distance than the debris flow cases. The fluid fraction has a significant influence on the flow dynamics; a higher fluid fraction often leads to higher velocities and long run-out distances, but lower kinetic energy, and it also affects the final deposition and deposition pattern considerably. The present study shows promising potential of a quantitative approach to the physics and mechanics of mass flows that may assist in the risk assessment of such large-scale destructive geological hazards or disasters.

Viscoelastic potential flow instability theory of Rivlin-Ericksen electrified fluids of cylindrical interface

A linear electrohydrodynamic Kelvin-Helmholtz instability of the interface between two viscoelastic Rivlin-Ericksen fluids enclosed by two concentric horizontal cylinders has been studied via the viscoelastic potential flow theory. The dispersion equation of complex coefficients for asymmetric disturbance has been obtained by using normal mode technique. the stability criteria are analyzed theoretically and illustrated graphically. The imaginary part of growth rate is plotted versus the wave number. The influences of dynamic viscoelastic, uniform velocities, Reynolds number, electric field, dynamic viscosity, density fluids ratio, dielectric constant ratio and inner fluid fraction on the stability of the system are discussed. The study finds its significance in Ocean pipelines to transfer oil or gas such as Eastern Siberia-Pacific Ocean oil pipeline.

Learnings From a New Slimhole LWD NMR Technology

This paper presents recent results obtained from a new 4.75-in. logging-while-drilling (LWD) nuclear magnetic resonance (NMR) tool. Data from several wells provided real-time operational insight and new petrophysical learnings. The new LWD technology offers an innovative capability to simultaneously measure NMR T1 and T2 distributions with reduced sensitivity to drilling mud conductivity and a real-time sensor motion-warning system. The real-time T1 and T2 spectra compare favorably with the data set retrieved from the tool memory. The LWD NMR measurements were followed by wireline (WL) NMR logging for comparison in three wells. In carbonate reservoirs, the main objective was to evaluate the new NMR tool’s capability in resolving carbonate pore size with slow NMR relaxation rates. Another set of NMR logs contained time-lapse repeat passes in a well drilled with oil-based mud (OBM) that traversed a clastic reservoir. The sequence of measurements identified rock types and provided a unique insight into the mud filtrate invasion process. In a carbonate reservoir, the LWD NMR real-time partial porosity estimates were in excellent agreement with the core-calibrated WL micro-, meso-, and macropore volumes. Another carbonate formation contained high-permeability layers embedded in a microporous rock, where the real-time LWD NMR logs successfully located the high-quality rock zones, later verified by WL logging. In the clastic reservoir, the while-drilling LWD NMR data indicated native light hydrocarbons, whereas the subsequent LWD reaming and WL NMR passes showed a displacement of native hydrocarbons by oil-based mud filtrate (OBMF). The native hydrocarbon signature observed by the LWD NMR tool was in good agreement with the mud gas log. OBMF invasion occurred shortly after drilling, indicated by the differences observed in the LWD NMR relogged data acquired several hours after the while-drilling pass. The WL NMR data, logged about 4 days after drilling, showed advanced stages of OBMF invasion, including formation water displacement and wettability changes in intermediate and large pores. Finally, the environmental noise remained low in the LWD NMR data set acquired in a well in which the mud salinity changed by several folds, indicating that mud salinity had little effect on the quality of LWD NMR logs in slim holes. The new slimhole LWD NMR technology demonstrated its robust capability to provide T1 and T2 logs through several examples. For the first time, a time-lapse comparison of NMR logs showed that OBMF invasion could occur in silty sands with high capillary-bound fluid fractions.

Thermo-hydro-mechanical response of a partially sealed circular tunnel in saturated rock under inner water pressure

The thermo-hydro-mechanical response of a partially sealed circular tunnel in saturated rock subject to inner water pressure with high temperature is investigated by the fully coupling thermo-hydro-mechanical model. The tunnel is assumed to be partially sealed, and the partially permeable condition of the boundary of tunnel is established using the Darcy’ law. Furthermore, a stress coefficient depending on the volume fraction of the pore fluid is quoted to establish the stress coordination conditions at the boundary of tunnel, and the solutions of temperature increment, displacement, pore water pressure and stress are obtained in the domain of Laplace transform. Based on the Crump method taking inverse Laplace transform, the numerical solution to the problem is presented. Numerical results are displayed graphically and analyzed in detail.

A novel magnetorheological braking system with variable magnetic particle volume fractioncontrolled by utilizing shape memory alloy

To address the shortcomings of decreasing shear yield stress of magnetorheological fluid due to temperature increase, magnetic saturation phenomenon under the action of a strong magnetic field, and decreasing performance of magnetorheological brake due to magnetic particle settling, a braking system of variable particle volume fraction of magnetorheological fluid modulated by shape memory alloy spring is proposed, which solves the shortcomings of constant particle volume fraction magnetorheological brakes. The brake temperature rises and automatically increases the volume fraction of magnetorheological fluid, leading to increase in the braking torque and ensuring stable braking performance at high temperatures. The magnetorheological fluid particle settling stability is enhanced, and energy consumption at idle is reduced. Based on the shape memory effect of shape memory alloy, the relationship between the output displacement of shape memory alloy spring and temperature, squeezing pressure and volume fraction of magnetic particles is established. Based on the microscopic body-centered tetragonal structure of magnetorheological fluid, the relationship between the volume fraction of magnetic particles and the magnetic permeability of magnetorheological fluid was established. Based on the rheological characteristics of magnetorheological fluid, the relationship between the braking torque of magnetorheological fluid and the magnetic permeability and the volume fraction of magnetic particles is established; and the finite element method was applied to simulate and analyze it. The results show that the magnetic permeability increases with the increase of the volume fraction of magnetic particles and the braking torque increase with the increase of the volume fraction of magnetic particles during the evolution of the magnetorheological fluid microstructure from single chain to body-centered tetragonal structure. When the volume fraction of magnetic particles in the magnetorheological fluid increased from 15% to 45%, the magnetorheological brake torque increased to 10.1N·m, and the braking performance of the magnetorheological brake improved by 14.3%. The experimental and theoretical analyses provide a theoretical basis for the design and manufacture of magnetorheological fluid brakes with variable particle volume fractions.

Qualification of Membrane Filtration for Planetary Protection Flight Implementation.

Planetary protection is the practice of preventing forward and backward contamination of solar system bodies. Spacecraft and associated surfaces are sampled to ensure compliance with bioburden requirements. Current planetary protection sampling and processing methodologies consist of extracting microbial cells from wipe or swab samples through a procedure (NASA Standard Assay) that includes sonication, heat shock, and pour-plate steps. The pour-plate steps are laborious and prolonged. Moreover, results can be imprecise because only a fraction of the sample fluid is plated for CFU enumeration (80% for swabs and 25% for wipes). Thus, analysis requires that a pour fraction extrapolation factor be applied to CFU counts to account for bioburden in the remaining sample volume that is not plated. This extrapolation results in large variances for data, decreasing the accuracy of spore bioburden estimation of spacecraft hardware. In this study, we investigated the use of membrane filtration as an alternative method to pour-plate processing. Membrane filtration is an appealing methodology for planetary protection because it can process greater sample volumes and reduces the data variance for bioburden enumeration. A pour fraction extrapolation factor is still applied for both swabs and wipes (92%), however, it is a greater pour fraction than the pour-plate method. Here we present data collected by the Jet Propulsion Laboratory and the Applied Physics Laboratory to experimentally determine the equivalency of membrane filtration to pour-plate methodology for implementation during the NASA Standard Assay. Additionally, we outline the planned procedures for two membrane filtration systems: Pall® Laboratory Manifold system and Milliflex® Plus Vacuum Pump System. Both systems demonstrated equivalence of the membrane filtration method to the pour-plate method.

GeoChemFoam: Direct modelling of flow and heat transfer in micro-CT images of porous media

GeoChemFoam is an open-source OpenFOAM-based numerical modelling toolbox that includes a range of custom packages to solve complex flow processes including multiphase transport with interface transfer, single-phase flow in multiscale porous media, and reactive transport with mineral dissolution. In this paper, we present GeoChemFoam’s novel numerical model for simulation of conjugate heat transfer in micro-CT images of porous media. GeoChemFoam uses the micro-continuum approach to describe the fluid-solid interface using the volume fraction of fluid and solid in each computational cell. The velocity field is solved using Brinkman’s equation with permeability calculated using the Kozeny-Carman equation which results in a near-zero permeability in the solid phase. Conjugate heat transfer is then solved with heat convection where the velocity is non-zero, and the thermal conductivity is calculated as the harmonic average of phase conductivity weighted by the phase volume fraction. Our model is validated by comparison with the standard two-medium approach for a simple 2D geometry. We then simulate conjugate heat transfer and calculate heat transfer coefficients for different flow regimes and injected fluid analogous to injection into a geothermal reservoir in a micro-CT image of Bentheimer sandstone and perform a sensitivity analysis in a porous heat exchanger with a random sphere packing.

Reassessing the optimal volume for malignancy detection in serous fluid cytology.

The international system for reporting serous fluid cytopathology (TIS) recommends submitting at least 50-75 mL of serous fluid to decrease false-negative results. However, prior studies did not agree on specific volume requirements or consensus adequacy criteria. Our study aims to assess whether fluid volume affects the adequacy rate and to assess the minimum volume necessary for optimal adequacy in pleural and peritoneal fluids. A total of 8530 serous fluid cytology cases were identified in the laboratory information system. Differences in mean fluid volume received in the laboratory were compared using an ANOVA Games-Howell test based on TIS category. The percentage of malignant diagnoses across the volume ranges of 0 to 5 mL, 5 to 10 mL, 10 to 25 mL, 25 to 50 mL, 50 to 75 mL, 75 to 100 mL, 100 to 150 mL, 150 to 250 mL, 250 to 500 mL, 500 to 2000 mL was compared in pleural and peritoneal fluids using a chi-square test, and a SiZer analysis was performed. Mean fluid volume in inadequate, atypical, and negative cases was significantly lower compared to positive cases. A SiZer analysis showed a positive relationship between the malignancy fraction of pleural and peritoneal fluids and fluid volume. The percentage of malignant diagnoses in pleural and peritoneal fluid samples increased significantly up to a volume range of 75-100 mL. There is a significant relationship between fluid volume, adequacy and detection of malignancy in serous effusion cytopathology. The malignancy fraction increases with larger fluid volumes but at least 75-100 mL of fluid should be submitted for optimal diagnosis of malignancy in pleural and peritoneal fluids.

Evaluation of slim-hole NMR logging for hydrogeologic insights into dolostone and sandstone aquifers

This study assesses the performance and limitations of slim-hole borehole nuclear magnetic resonance (NMR) technology from a hydrogeologic perspective in fractured, porous rock. NMR logging was carried out in dolomitic and sandstone bedrock boreholes at two research test sites in Ontario, Canada, where aquifer and aquitard units provide a range of clay contents as well as a variety of primary and secondary porosity types (e.g. discrete fractures, reefal structures, vugs and karstic conduits). Results were compared to core measurements, geophysical logs, and hydrogeophysical testing. The vertical response curve of the instrument tested was found to produce 60% of the signal from within a 0.2m span surrounding the measuring point. The repeatability of the total porosity measurements in stationary mode is excellent where the porosity is greater than 0.15. Below that threshold, repeatability is scattered at ±0.05 porosity about the mean, with the variability primarily within the clay- and capillary-bound fractions. The NMR porosity estimates agreed with core measurements to within ±0.04 porosity in both the dolostone and sandstone, but the correlation deteriorates in finely bedded lithologies, and where fracturing is present. Much of the discrepancy is attributed to scaling in a finely layered geologic sequence, as the core samples are much smaller than the entire volume measured with NMR probes. Data collection with the probe in motion (continuous logging) added variability to the response when compared to stationary recordings. Although broadscale trends were comparable, the details and depth-specific insights of the bound fluid fractions varied with logging rates. Overall, NMR provides a robust measurement of the bulk matrix porosity and pore size distribution of lithologies intersected, both of which are critically important parameters in understanding hydrogeologic conditions and contaminant distributions in layered sedimentary rock systems.

Calculation of volume fractions regardless scale deposition in the oil industry pipelines using feed-forward multilayer perceptron artificial neural network and MCNP6 code

During the production of oil and gas, barium sulfate (BaSO4) scale occurs on the inner walls of the tubes leading the reduction of the internal diameter, making the fluid passage difficult and complicating the calculation of volume fractions of fluids. In this sense, this study presents a methodology for the development of volume fractions of fluids multiphase meters and the prediction of barium sulfate (BaSO4) scale thickness. The spectra obtained by two NaI(Tl) detectors that record the transmitted and scattered beams are used as input data for the artificial neural network without the need of any parametrization method. Theoretical models for annular flow regime were developed using MCNP6 code. Different volume fractions and scale thickness values of oil-water-gas were generated as a data set to train and evaluate the neural network. The results indicate that it is possible to calculate the volume fraction regardless the scale thickness in offshore oil industry pipes. More than 88% of the results showed errors below 5% for all investigated samples.

CHARACTERISTICS OF CHANGES IN QUALITATIVE PROPERTIES OF ORAL FLUID IN CHILDREN WITH CONGENITAL NONUNION OF THE PALATE

According to publications in scientific periodicals, children with congenital malformations of the development are increasingly born, including those with localization on the face, head and neck. Anatomical inferiority of tissues in the area of the slit defect of the palate creates the preconditions for the formation of pathological symptom complex, which contributes to the progression of inflammatory-dystrophic changes in the oral cavity.
 The aim of the study was to study the violations of the qualitative properties of oral fluid in children with congenital nonunion of the palate in the preoperative period.
 For an in-depth examination of 58 children who were under our supervision, a group of 25 patients aged from 4 to 6 years was formed. Of these, 14 had a unilateral cleft and 11 had a bilateral cleft.
 The substrate for the study was unstimulated fraction of oral fluid. The salivation rate was studied, the concentration of hydrogen ions in it, its optical density, viscosity, α-amylase activity, levels of medium weight molecules, sialic acids, total protein, oxyproline were determined. The degree of mineralizing potential was determined by magnesium, calcium and phosphorus.
 At the time of the examination in children with unilateral clefts, a decrease in the amount of oral fluid was found, which was expressed by a decrease in the secretory activity of the large and small salivary glands by 1,3 times. The concentration of ions is visible in it and the activity of α-amylase decreased by 1.3 times. The optical density and viscosity also increased by 1,3 times, the number of medium weight molecules, the level of sialic acid and total protein increased by 1.5 times, and oxyrolin by 1.6 times.
 The analysis of indexes that showed the mineralizing potential of oral fluid mineralizing potential of oral fluid allowed to determine the fact that in patients of this group it decreased by 1,7 times and this occurred against the background of a decrease in calcium and magnesium by 1,5, with an increase in phosphorus by 1.3 times. This imbalance led to falling in calcium-phosphorus ratio by 1,8 times.
 In children with congenital malformations of the palate there is a decrease in the functional activity of large and small salivary glands, reduced buffering capacity of oral fluid, which occurs against the background of falling mineralizing potential of oral fluid, imbalance of calcium, phosphorus and magnesium. This affects the calcium-phosphorus ratio, thus creating optimal conditions for demineralization of tooth hard tissues. Changes in physicochemical and biochemical properties of mixed saliva are determined, which is the basis for the prolongation and progression of pathological processes in the oral cavity that take place in them.
 The complex of treatment-and-prophylactic measures developed by us, aimed at improving the level of components of homeostasis of the oral cavity before surgery, is being tested for the future.