Fraction Of Impurities Research Articles

An integrated review on the role of different biocatalysts, process parameters, bioreactor technologies and data-driven predictive models for upgrading biogas.

An integrated review on the role of different biocatalysts, process parameters, bioreactor technologies and data-driven predictive models for upgrading biogas.

Himitsu Bako of NO2 Mixtures: Characterization of NO2 Reference Material Using FTIR Spectroscopy in Middle Infrared Region

In this work, we investigate how much information a conventional infrared spectroscopic technique (FTIR) can yield for NO2 reference materials in the range of concentrations between 100 to 2500 μmol/mol. The amount fraction of 100 μmol/mol corresponds to the actual maximum for NO2 emissions by modern Euro 6 vehicles and is suitable for Portable Emissions Measurement Systems (PEMS) calibration. A set of measurements of four reference mixtures was performed. For the analysis, we developed an efficient and simple algorithm, based on the integration of rovibrational bands, yielding the molar fractions of NO2 (including dimer) and several impurities, such as N2O and HNO3. It resembles a Japanese puzzle box, Himitsu Bako, since different mixture components should be addressed in a certain order to unravel a complete composition. The algorithm was successfully applied to the recorded spectra. For example, the uncertainties for low NO2 amount fractions were shown to be limited essentially by the quality of reference spectroscopic data for the monomer (HITRAN database in the current work), and not by the measurement procedure. Shortcomings, further development, and improvements of the experimental set-up as well as of the evaluation algorithm are addressed.

Transitioning from anhydrous Stanfieldite-type Na2Fe(SO4)2 Precursor to Alluaudite-type Na2+2δFe2-δ(SO4)3/C composite Cathode: A Pathway to Cost-Effective and All-Climate Sodium-ion Batteries

Transitioning from anhydrous Stanfieldite-type Na2Fe(SO4)2 Precursor to Alluaudite-type Na2+2δFe2-δ(SO4)3/C composite Cathode: A Pathway to Cost-Effective and All-Climate Sodium-ion Batteries

Estimates of required impurity fraction for EAST divertor detachment

During the EAST radiative divertor experiments, one of the key challenges was how to avoid the occurrence of disruptive events caused by excessive impurity seeding. To estimate the required impurity fraction for divertor detachment, we introduce a reduced edge plasma radiation model. In the model, based on the momentum conservation along the magnetic field line, the upstream pressure is determined by the plasma density and temperature at the divertor target, and then the impurity radiation loss is obtained by the balance of the heat and particle fluxes. It is found that the required impurity fraction shows a non-monotonic variation with divertor electron temperature ( ) when . In the range of , the position near the valley of required impurity fraction corresponds to strong plasma recombination. Due to the dependence of the volumetric momentum loss effect on the in the range of , the required impurity fraction peaks and then decreases as is increased. Compared to neon, the usage of argon reduces the impurity fraction by about twice. In addition, for the various fitting parameters in the pressure–momentum loss model, it is shown that the tendency of required impurity fraction with always increases first and then decreases in the range of , but the required impurity fraction decreases when the model that characterizes the strong loss in pressure momentum is used.

HgCdTe surface passivation with low-temperature plasma-enhanced atomic layer deposited HfO2

HgCdTe surface passivation with low-temperature plasma-enhanced atomic layer deposited HfO2

Power handling in a highly-radiative negative triangularity pilot plant

Abstract This work explores detailed power handling solutions for a class of high-field, highly-radiative negative triangularity (NT) reactors based around the MANTA concept [Rutherford et al. (2024)]. The divertor design is kept as simple as possible, opting for a standard divertor with standard leg length. FreeGS is used to create an equilibrium for the boundary region, prioritizing a short outer leg length of only ∼50 cm (∼40% of the minor radius). The UEDGE code package is used for the boundary plasma solution, to track plasma temperatures and fluxes to the divertor targets. It is found that for PSOL = 25 MW and nsep = 0.96 × 1020 m−3, conditions consistent with initial core transport modeling, little additional power mitigation is necessary. For a fixed impurity fraction of just 0.13\% Ne in the plasma, the peak heat flux density at the more heavily loaded outer targets falls to 7.8 MW/m2, while the electron temperature, Te, remains just under 5 eV. Scans around the parameter space reveal that even at densities lower than in the primary operating scenario, PSOL can be increased up to 50 MW, so long as a slightly higher fraction of extrinsic radiator is used. With less than 1% neon (Ne) impurity content, the divertor still experiences less than 10 MW/m2 at the outer target. Design of the plasma-facing components includes a close-fitting vacuum vessel with a tungsten inner surface as well as FLiBe-carrying cooling channels fashioned into the VV wall directly behind the divertor targets. For the seeded heat flux profile, Ansys Fluent heat transfer simulations estimate that the outer target temperature remains at just below 1550◦C. Initial scoping of advanced divertor designs shows that for an X-divertor, detachment of the outer target becomes much simpler, and plasma fluxes to the targets drop considerably with only 0.01% Ne content.

Measurement of CO2 leakage from pipelines under CCS conditions through acoustic emission detection and data driven modeling

Measurement of CO2 leakage from pipelines under CCS conditions through acoustic emission detection and data driven modeling

Determination of non-combustible impurities in detonation nanodiamond powder

The study of the physicochemical (including adsorption) properties of nanodiamond requires the possibility of reproducible generation of the carbon surface of an individual particle without metal impurities of unknown composition. This kind of surface can be obtained through an additional deep cleaning of a commercially available sample. This article is dedicated to the study of the composition of non-combustible impurities of detonation nanodiamond powder. Using inductively coupled plasma mass spectrometry, iron and titanium were identified as the main metal components of the unburned residue, and the presence of Cr, Ni, Zr, As, and Sb was qualitatively established. The expected composition of the main molecular ions formed on the surface of the unburned residue in the course of laser desorption/ionisation mass spectrometry was presented. Based on the results of mass spectrometry analysis, a method of two-stage chemical treatment of detonation nanodiamond powder was proposed, which allowed reducing the mass fraction of non-combustible impurities during annealing in air from 2.0 to 0.1%.

Testing validity of 1D models for impurity fraction scaling for divertor detachment with EDGE2D-EIRENE

Predictions of the Huber–Chankin (HC) scaling for the upstream impurity fraction were verified in a series of EDGE2D-EIRENE (‘code’) runs for highly radiating plasmas with nitrogen injection. The main quantity extracted from the code was poloidally averaged, from X-point to X-point, separatrix impurity fraction cZ in the main scrape-off layer (SOL). Variation of the main working gas (H, D and T) revealed a qualitative agreement between the model and code results owing to the very large isotope difference in the predicted cZ values caused primarily by the inverse isotope mass dependence of the H-mode power threshold assumed in the HC model and implemented in the code. At the same time, the variation of the toroidal field and safety factor in deuterium cases yielded no correlation between the model predictions and code results. The code showed much higher local impurity fractions (fZ ) in the divertor compared to the main SOL, as well as large case-to-case variations in the divertor to the main SOL ratio of impurity fractions. The analysis of code results has wide-ranging consequences not only for the HC model, but also for other similar 1D models which use simple geometry ignoring strong neutral recycling in the divertor/ Different topology makes plasma parameters in the divertor and main SOL very different, resulting in different impurity charge state composition. Missing mechanisms in 1D codes (e.g. friction and thermo-forces exerted on impurity ions by main working gas ions) lead to impurity density redistribution. Neglecting all above factors, 1D models assume a constant impurity fraction along field lines.

UEDGE modeling of plasma detachment of CFETR with ITER‐like divertor geometry by external impurity seeding

AbstractEfficient handling of high heat flux on the plasma‐facing components, particularly the divertor targets, poses a significant challenge for the Chinese Fusion Engineering Testing Reactor (CFETR) with fusion power of Gigawatt. This work investigates the divertor plasma detachment of CFETR with a standard ITER‐like divertor geometry by neon (Ne) or argon (Ar) impurity seeding using UEDGE code. The cross‐field drifts terms are switched off, and fluid neutral models and a “fixed‐fraction” impurity model are applied to enable efficient simulations for the study of CFETR detachment. In order to reduce the heat load on the divertor targets below the acceptable level (<10 MW/m2), the impurity fraction (f), pumping speed (S), and upstream density are varied to identify the suitable operations window during Ne seeding. The effects of Ne and Ar impurities on the plasma detachment are compared. It is found that with the power across the core‐edge interface PSOL = 200 MW and separatrix density of 2.8 1019 , Ne impurity fraction ≥1.7%, and Ar impurity fraction ≥0.24% can achieve the partial detachment. Achieving similar total radiation power (˜148 MW), the Ne fraction is 2.3% and the Ar fraction is 0.24%. Moreover, the simulation results indicate that Ar exhibits better power radiation efficiency and core compatibility compared with Ne.

Comparative analysis of physicochemical parameters of buckwheat perga of honey of different regional origins

Studies of beekeeping products reveal the presence of a significant complex of biologically active substances in them, which arouses great interest among scientists and specialists in the field of medicine and nutrition. One of the little-studied products – perga, is characterized by a unique composition of complex compounds, characterized by their natural harmony, bioavailability and synergistic interaction. This research substance, which is the result of the active activity of bees, includes a balanced spectrum of biologically active components that can affect various aspects of human health. In particular, its potential is considered in the context of strengthening immunity, increasing energy reserves and general support of physiological processes. Such a well-known product can become an important addition to the diet and an approach to maintaining optimal health. The physico-chemical and organoleptic characteristics of buckwheat perga from different regions were studied in order to establish possible differences in their composition and quality. The analysis of perga samples from the Boryspil and Pereyaslav-Khmelnytsky districts showed that the mass fraction of mechanical impurities in both cases is 0 %, confirming their high quality and purity. It was determined that the moisture content of the perga from Boryspil district is 8.7 %, and from Pereyaslav-Khmelnytskyi – 7.6 %, which may be due to differences in the conditions of collection and storage. The pH level in perga from Boryspil district is 5, and from Pereyaslav-Khmelnytskyi – 3.9, which indicates possible differences in chemical conditions. The study also revealed a difference in the mass content of flavonoid compounds: in perga from Boryspil district, this indicator is 3.7 %, and from Pereyaslav-Khmelnytskyi – 2.5 %. The organoleptic analysis showed a high index of color (5 points) for both areas, indicating stability and intensity of color. Taste and smell received 4.8 and 4.5 points, respectively, confirming the presence of high-quality aroma and taste. Appearance and consistency were also highly rated (4.4 and 4.8 points), indicating the variety and naturalness of the lumps and their crumbly structure. The general analysis confirms the presence of differences in the composition and characteristics of buckwheat perga from different regions. These differences may be related to environmental factors, but they correspond to DSTU 7074:2009.

Impurity induced modulational instability in Bose-Einstein condensates

Impurity induced modulational instability in Bose-Einstein condensates

Analysis of the effect of mechanical impurities in water on the hydroabrasive wear of the turbines of the Bozsu hydroelectric power plant

The peculiarity of the operation of hydropower facilities (pumping stations and hydroelectric power plants) in the Republic of Uzbekistan is that the equipment works with liquids containing a large amount of mechanical impurities. The purpose of the research is to assess the effect of the content of mechanical impurities in water on waterjet wear. The object of research is the Bozsu HPP (Uzbekistan). To assess the hydroabrasive properties of a liquid with impurities, an analysis of the granulometric and mineralogical composition of sediments and especially those fractions of impurities that pose a danger was carried out. For water passing through the turbins of the Bozsu HPP, these are fractions of feldspar and quartz. Most of the composition of mechanical impurities are feldspar minerals (58.46% with an average diameter of 0.093 mm). The total content of hazardous fractions (feldspar and quartz) is 77.07% or 0.3-0.4 kg/m3, which exceeds the maximum permissible norm (0.2 kg/m3). But at the same time, no dangerous fractions in diameter (more than 0.25 mm) were detected. A full-scale inspection of the turbine parts showed that waterjet wear is present. The type of waterjet wear is fine-scaled wear with rare, separately located, shallow scales and deep (deep) type of wear with long grooves. The degree of waterjet wear quantitatively and qualitatively, this can be attributed to the wear of low and medium activity.

Применение метода Бриджмена для получения термоэлектрического кремния, легированного германием и фосфором

Heavily donor or acceptor doped metallurgical silicon is a promising candidate as a high-temperature thermoelectric energy converter due to the extremely low cost of its fabrication. The problem of silicon-based thermoelectric materials is the high value of the thermal conductivity; however, modern technologies offer several options for solving this problem at once. In the present work, silicon ingots heavily doped using Si:P compound were grown by the Bridgman directional crystallization method with a small (up to 5 at. %) germanium impurity fraction. The main thermoelectric parameters of the material were measured in a wide temperature range (50 – 800 °C). These are Seebeck coefficient, electrical conductivity and thermal conductivity. Based on the measurement results, the value of the thermoelectric figure of merit was calculated. The latter determines the value of the thermoelectric conversion efficiency. The study of electrical properties shows that phosphorus from the SiP compound is introduced into the lattice as a dopant and creates a high concentration of conduction electrons. The chemical analysis of the ingots showed the presence of additional background impurities, the concentration and composition of these impurities vary over the bulk of the sample. Despite the presence of impurities, the material demonstrates relatively high thermoelectric characteristics, and the efficiency is at the level of the best world results. A further potential for optimizing thermoelectric characteristics due to the possibility of a fine-grained polycrystalline structure formation is discussed.

Improvement of methods for controlling power oil of cooling tower recycling water supply units at Rivne nuclear power plant

The relevance of the study is conditioned upon the fact that at nuclear power plants, water pumping units using energy oils are operated in the heat exchange equipment of power units. The diagnostic criteria of oils allow identifying defects in the operation of technological equipment. The purpose of the work – to increase the reliability of the operation of oil-filled power equipment by improving the monitoring of the physical and chemical properties of power oil TP-30. The main attention is devoted to increasing the reliability of the operation of oil-filled power equipment by improving the monitoring of the physical and chemical properties of TP-30 power oil. Experimental studies were conducted by chromatography, and gas and liquid extraction using appropriate laboratory equipment. When exploring the content of chemical elements in the segments of the thrust bearing of the cooling tower pumping unit, which is based on Sn, an increase in the content of copper Cu and Sb was observed, which exceeded the standard by an average of 1.2 and 1.1 times, respectively. Most of the analysed physical indicators of oil quality (water content, kinematic viscosity, flash point, acid number) did not demonstrate deviations from the standard values. Only an increase in the mass fraction of mechanical impurities by 0.0026% relative to the standard was noted during the incoming inspection of TP-30 oil. The results of the operational control of the oil in terms of a set of physical indicators fully complied with the established technological standards. The highest content of soluble gases in the oil (0.56% by volume) was recorded for propylene (C3 H6 ). It is recommended to use the relative content of soluble gases in Tp-30 oil to C3 H6 when identifying degradation processes. The absence of residuals of circulating power oil TP-30 in the surface waters of the Styr River during the operational event was established. Generalisations have been generalised about the necessity of expanding the diagnostic criteria for the quality of TP-30 oil, in particular, expanding the list of its physical indicators. In practical terms, the results obtained can be useful for monitoring the quality of other brands of petroleum oils in the systems of turbine units of nuclear power plants, which is important in terms of the safe operation of heat exchange equipment

Probing Ferroelectric Behavior in Sub-10 nm Bismuth-Rich Aurivillius Films by Piezoresponse Force Microscopy.

Sub-10 nm ferroelectric and multiferroic materials are attracting increased scientific and technological interest, owing to their exciting physical phenomena and prospects in miniaturized electronic devices, neuromorphic computing, and ultra-compact data storage. The Bi6Ti2.9Fe1.5Mn0.6O18 (B6TFMO) Aurivillius system is a rare example of a multiferroic that operates at room temperature. Since the formation of magnetic impurity phases can complicate attempts to measure ferromagnetic signal intrinsic to the B6TFMO multiferroic phase and thus limits its use, herein we minimize this by utilizing relatively large (49%) bismuth excess to counteract its volatility during sub-10 nm growth. X-ray diffraction, electron microscopy, and atomic force microscopy show sample crystallinity and purity are substantially improved on increasing bismuth excess from 5 to 49%, with the volume fraction of surface impurities decreasing from 2.95–3.97 vol% down to 0.02–0.31 vol%. Piezoresponse force microscopy reveals 8 nm B6TFMO films are ferroelectric, with an isotropic random distribution of stable in-plane domains and weaker out-of-plane piezoresponse. By reducing the volume fraction of magnetic impurities, this work demonstrates the recent progress in the optimization of ultra-thin B6TFMO for future multiferroic technologies. We show how the orientation of the ferroelectric polarization can be switched in 8 nm B6TFMO and arrays can be “written” and “read” to express states permitting anti-parallel information storage.

Improved residue on ignition method for the mass fraction of inorganic impurities of pure organic substances

Improved residue on ignition method for the mass fraction of inorganic impurities of pure organic substances

Impurities in commercial titanium dental implants – A mass and optical emission spectrometry elemental analysis

Impurities in commercial titanium dental implants – A mass and optical emission spectrometry elemental analysis

Exploring the composition of propolis as a subject of processing into food products

The object of the research is samples of propolis collected by various means from different regions of Ukraine. The main problem that is being solved is the search for optimal, efficient, and food industry-approved methods of collecting propolis as a raw material of processing into food products. The influence of the main methods of propolis collection on the key quality indicators of propolis for its application as a raw material in the food industry has been studied. The differences in the main raw material indicators across regions of Ukraine have been evaluated. The use of propolis collection methods that do not meet the safety requirements of the food industry is a common practice in beekeeping farms. The acceptability of the raw material for use in the food industry is based on its compliance with the requirements of current regulatory and legal acts on quality. However, the updating and revision of regulatory acts in view of production realities occur slowly and with significant delays. This approach reduces the volume of raw materials available for industrial use due to technical barriers and outdated regulatory acts on quality. In the course of the research, results were obtained based on such indicators as the mass fraction of wax, mechanical impurities and flavonoid compounds in propolis collected from three regions of Ukraine. The levels of indicators in the studied samples do not meet the requirements defined by DSTU 4662:2006. At the same time, the regulatory requirements of DSTU 4662:2006 and the research methods do not align with the finalized project ISO/DIS 24381, which is currently in the final stages of adoption as the primary international standard. The use of means of collection in the production of propolis raw materials, which are allowed to come into contact with food products, taking into account also the review of quality regulatory acts and bringing them into line with international documents, can contribute to improving the availability of this product as a food raw material. Propolis producers should pay attention to the sources of propolis located in ecologically clean areas with minimal industrial impact and adhere to proper beekeeping practices to obtain high-quality raw materials. The obtained results can be used to develop an industrial technology for the production of propolis as a raw material for food production.

Low Z gas mixing effects of Ar and Xe multicharged ions in electron cyclotron resonance ion source

An electron cyclotron resonance (ECR) ion source (ECRIS) has wide applications such as cancer therapy and material synthesis. We have constructed a single ECRIS capable of producing various ions with low to high mass/charge ratio, and have been conducting various experiments. We focus on the efficient production of multicharged ions and aim to increase the yield of multicharged ions by new effects of electromagnetic waves in ECRIS. We investigated the possibility of selective heating to low Z ions under low Z gas mixing. Therefore, as a preliminary step of these experiments, the low Z gas mixing effect with rare gases are investigated. The optimum mixing ratio of the main gas Ar and the low Z gas He was investigated by varying the mixing ratio. The Ar multicharged ion beam current, impurity fraction and plasma parameters were measured. As a result, it was confirmed that the Ar multicharged ion yield was sufficient reproducibly increased by mixing He gas into Ar plasma. In addition, this from the measured plasma parameters is not an effect of the plasma parameters, but maybe a cooling effect.