Higher Temperature Values Research Articles

Climatology of waterspouts in the Balearic Islands (1989–2020)

The article analyses the waterspouts recorded in the Balearic Islands (Spain) between 1989 and 2020. The extensive database used includes 234 waterspout events, which we analysed to establish their annual, monthly, seasonal and weekly spatial, temporal and hourly distribution. The autumn months account for 65% of all the waterspout events, with the highest frequency seen in September. They occur most frequently between 8:00 and 10:00 in the morning. We carried out a synoptic classification of the days on which waterspouts were recorded, observing that a synoptic trough pattern at 500 hPa over the Iberian Peninsula, which generates a south-westerly flow over the area under study, was the most conducive waterspout-creating condition (present in 25.3% of the events). Their relationship with the sea surface temperature was also analysed, revealing a higher frequency of waterspouts with higher temperature values, particularly between 23 and 26 °C. Finally, we examined the frequency of waterspouts in relation to the daily Western Mediterranean Oscillation regional teleconnection pattern index values, finding that waterspouts were more common on days when the indices were closer to 0.

Three-dimensional modelling of a self-sustained atmospheric pressure glow discharge

The atmospheric pressure glow discharge (APGD) is a relatively simple and versatile plasma source used in diverse applications. Stable APGD operation at high currents, generally a challenge due to instabilities leading to glow-to-arc transition, has been demonstrated using actively-controlled cathodic cooling. This article presents the computational modelling and simulation of a self-sustained direct-current APGD in helium within a 10 mm pin-to-plate inter-electrode gap for currents ranging from 4 to 40 mA. The APGD model is comprised of the conservation equations for total mass, chemical species, momentum, thermal energy of heavy-species and of free electrons, and electric charge. The model equations are discretized using a nonlinear variational multi-scale finite element method that has demonstrated superior accuracy in other plasma flow problems, on a temporal and three-dimensional computational domain suitable to unveil the potential occurrence of instabilities. Modelling results show good agreement with experimental measurements of voltage drop and the same trend but higher values of temperature. The higher temperatures obtained by the simulations appear to be due to the absence of a near-cathode heat dissipation model. The results also reveal that the distribution of electron density and of the ratio of atomic helium ions to total ions transitions from monotonically increasing away from the cathode to presenting a minimum near the centre of the gap with increasing current.

Ageing Rate of Li-Ion Battery Cells As a Function of Temperature, C-Rate, and State of Health

The ageing rate and consequentially service life of mass-produced lithium-ion batteries depends on many external and internal factors. Some of the more important ones are the charge-discharge rate, ambient temperature, electrode thickness and state of health (SoH). This makes the estimation of the lifetime of battery cells very challenging and time-consuming. This motivates the development of models capable of determining the ageing behavior of a battery cell with relatively little experimental data.In this study1 we build on our previous work2,3 and use Arrhenius plots of the ageing rate to analyze the service life of battery cells in a relatively simple and straightforward way. We cycle aged two types of cells – commercial 5 Ah high-energy 21700 cells with Si/graphite anode (≈3 % Si) and LixNi0.90Co0.05Al0.05O2 + LiyNiO2 (NCA + LNO) cathode and lab-made 0.1 Ah pouch cells with LixNi0.33Mn0.33Co0.33O2 (NMC111) cathode and graphite anode. The ageing is ensured by systematically cycling the cells in a temperature range of -15 °C to 60 °C at various C-rates (0.2 C – 1 C).The capacity fade data is analyzed to obtain the ageing rate (% of SoH per cycle) as a function of temperature, which forms the V-shaped Arrhenius plots shown in Figure 1. Each set of data clearly shows two slopes that cross at intermediate temperatures. As shown previously experimentally2,3 and theoretically,4 the slopes correspond to two ageing mechanisms – lithium plating in the low temperature region and growth of solid-electrolyte interface (SEI) at high temperature region. The intersection of the two Arrhenius slopes denotes a transition between the dominating ageing mechanism and also denotes the optimum temperature at which the battery cell has the highest service life.By analyzing the data, we show that the crossover temperature shifts towards higher temperature values with increasing C-rate and increasing thickness of the anode, as both increase the electrode area-normalized current. The crossover temperature depends on the SoH of the battery. The precise trend depends on the cell chemistry, as we observe increase of the crossover temperature for one type of cells and decrease of crossover temperature for the other type of cells. The shift of the crossover temperature to lower temperatures observed in pouch cells could be explained by a more rapid loss of cyclable lithium, whereas the shift towards higher C-rates observed in commercial 21700 cells can be observed due to increasing practical C-rates as the electrodes degrade and loose some of their initial capacity. By using relatively little input data, we are able to predict the temperature- and C-rate-dependent end of life of a battery cell with good precision.Evaluating the Arrhenius-type dependences of the ageing rate of the battery cells provides valuable insights for use in battery management systems and extending the service life of battery cells. Acknowledgements Gints Kucinskis acknowledges Latvian Council of Science project “Cycle life prediction of lithium-ion battery electrodes and cells, utilizing current-voltage response measurements”, (no. LZP-2020/1-0425). The part of the research performed at ZSW was carried out in the framework of the industrial collective research program (IGF no. 20884 N/2). It was supported by the Federal Ministry for Economic Affairs and Energy (BMWi) through the AiF (German Federation of Industrial Research Associations eV) based on a decision taken by the German Bundestag. References G. Kucinskis, M. Bozorgchenani, M. Feinauer, M. Kasper, M. Wohlfahrt-Mehrens, T. Waldmann, submited to J. Power Sources.T. Waldmann, M. Wilka, M. Kasper, M. Fleischhammer, and M. Wohlfahrt-Mehrens, J. Power Sources, 262, 129–135 (2014) https://linkinghub.elsevier.com/retrieve/pii/S0378775314004352.M. Bozorgchenani, G. Kucinskis, M. Wohlfahrt-Mehrens, and T. Waldmann, J. Electrochem. Soc., 169, 030509 (2022) https://iopscience.iop.org/article/10.1149/1945-7111/ac580d.X.-G. Yang and C.-Y. Wang, J. Power Sources, 402, 489–498 (2018) https://linkinghub.elsevier.com/retrieve/pii/S0378775318310462. Figure 1. Arrhenius plots based on ageing rate for (a-e) commercial 21700 cells at 100 %, 95 %, 90 %, 85 % and 80 % of SoH and (f,g) lab-made pouch cells at 100 % and 95 % SoH. Figure 1

Geometrical and electrical optimization of NS-SDBD streamwise plasma heat knife for aircraft anti-icing

Ice accretion on aircraft encountering supercooled water droplets in clouds poses great risks to flight performance and safety. With the aim of optimizing the newly developed streamwise plasma heat knife method for anti-icing, a parametric investigation is carried out in this work. The influence of the detailed voltage profile on the heating effects of a Surface Dielectric Barrier Discharge driven by Nanosecond Pulses (NS-SDBD) is investigated, and a comparison of the anti-icing performance among different configurations of streamwise plasma heat knife is made. The results show that columnar high-temperature regions produced by a multi-streamer discharge appear at small pulse rise time, but become diffuse as the pulse rise time increases. An optimal pulse rise time exists to provide a wide range and high value of temperature, which is found to be 150 ns for the setup in the present study. The influence of the pulse fall time is much weaker than that of the rise time. The range and value of the temperature decrease with increasing pulse fall time. A greater pulse width is found to improve the heating effect by increasing the discharge power. When a spanwise electrode is placed connecting the streamwise electrodes of the streamwise plasma heat knife at the airfoil leading edge, the anti-icing performance becomes poorer, whereas good performance is achieved when the spanwise electrode is at the edge of the streamwise electrodes. Based on this, a three-level configuration of the plasma heat knife is proposed, and its anti-icing performance is found to be much better than that of the original configuration.

PSVI-1 Effects of Rumen-Protected Methionine on Reproduction and Body Temperature of Nelore Cows in hot and Humid Environments

Abstract This study aimed to evaluate the effects of dietary supplementation of rumen-protected methionine (RPM) on the body temperature and conception rate of Nelore cows exposed to high temperature and humidity index (THI) values. This study was realized on a commercial beef farm located in the north of Brazil (5º 31’ 39” S, 48º 49’ 18” W). At d-31, 31 days before the FTAI protocol, a total of 563 lactating multiparous Nelore cows were divided into two treatments, with three blocks each, the control group (CG) and methionine group (MG). Both groups were kept on tropical pastures and received a mineral supplement. The MG Group was supplemented with 3g RPM/100g during 77 days, and the expected mineral supplement intake of both groups was 100g/cow/day. Between d0 and d9 of the FTAI protocol, a subset of groups of cows (n=142) remained with a data logger attached to the progesterone device, to monitor intravaginal temperature (IT) every 30 min. During the period that the cows remained with the dataloggers the minimum, average, and maximum THI were 72.76, 78.02, and 83.28, respectively. Pregnancy diagnosis was realized 35 days after the artificial insemination and the conception rate was calculated as the number of pregnant cows/inseminated cows. Data were analyzed using the JMP GLIMMIX procedure. RPM supplementation did not affect the conception rate (CG = 64.36% vs. MG = 58.19%, P >0.05). Intravaginal temperature from day 1 to day 8, between 0630 and 2030 h and between 2200 and 0100 h were lower (P≤0.05) for MG in comparison with CG. The average and the maximum IT were, respectively, 38.94ºC, 40.88ºC for MG and 39.02ºC, and 41.38ºC for CG. In conclusion, the supplementation of rumen-protected methionine reduced the internal body temperature in Nelore cows submitted to high THI environments, during the hottest hours of the day, but does not affect the conception rate.

Phase recognition and spectroscopic characteristics of single-phase Tb3+ doped Gd4Al2O9 nanophosphors for NUV energized advanced photonic appliances

Self-propagating solution combustion (SC) synthetic method has been used to prepare single-phase Gd4-xAl2O9:xTb3+ (x = 1–6 mol%) powdered samples. Various structural, morphological and optical studies are performed in order to characterize the designated nanocrystalline materials. Phase recognition and refinement parameters of doped phosphors are explored via X-ray diffraction (XRD) assisted Rietveld refinement technique which authenticates that powdered samples are crystallized into monoclinic crystal system having P21c space group. Williamson-Hall (W–H) linearly fitted method along with Scherrer's formula is employed to calculate the average crystallite size of doped materials which are found to be in the domain of nano-range. Transmission electron microscopy (TEM) reveals the presence of non-uniform agglomerated particles with characteristics porosity. The emission profile of all doped samples possesses sharp emission lines centred at 416, 438, 460, 486, 543, 591 and 621 nm due to 5D3 → 7F5, 5D3 → 7F4, 5D3 → 7F3, 5D4 → 7F6, 5D4 → 7F5, 5D4 → 7F4, and 5D4 →7F3 intra-configurational transitions of Tb3+ ion, respectively. The optimized doping concentration of Tb3+ ion for Gd4Al2O9 host is found to be 4 mol%. The resulting chromaticity coordinates (x, y) and high correlated color temperature (CCT) values of doped phosphors endorsed their usage in near ultra-violet NUV energized solid-state display appliances.

ASSESSMENT OF THERMAL POLLUTION OF SARANSK USING MULTI-ZONE SATELLITE IMAGES

The article considers the possibilities of using multi-zone satellite images of Landsat-8 for the purposes of operational monitoring and assessment of the thermal balance in the urban environment. The calculation of the surface temperature of the earth of Saransk was performed using the Landsat Surface Temperature QGIS module. The analysis of the dynamics of changes in the heat balance of the city in different seasons of the year during the study period is carried out. Based on the data of remote sensing of the Earth, the analysis of the differentiation of the temperature of the Earth’s surface is carried out, the areal main areas of distribution of thermal anomalies in the urbanized territory are identified. The conclusion is made about the dependence of the location of the industrial zones of the city and the territories with the highest temperature values, measures aimed at improving the comfort of the urban environment are proposed.

How to identify and characterize novel transaminases? Two novel transaminases with opposite enantioselectivity for the synthesis of optically active amines

Amine transaminases (TAs) are attractive biocatalysts for the synthesis of chiral aromatic amines representing highly valuable motifs of APIs. The increased industrial need of novel methods to produce chiral amines for APIs resulted in an emerged discovery of new TAs. Joining the current wave of TA related research, this study reports the identification of genes encoding an (S)-selective TA from Pseudomonas psychrotolerans TA (PpS-TA) and an (R)-selective TA from Shinorizobium sp. TA (SrR-TA) by sequence data mining. Functional analysis of the novel TAs revealed their pH profile, thermal stability, optimal buffer system, DMSO tolerance, and operational stability in kinetic resolution (KR) of racemic 1-phenylethane-1-amines. The (S)-selective PpS-TA maintained its operational stability even at high temperature and pH values, enabling conversions from racemates approaching the optimal ∼50% value of a highly selective KR. Although with lower activity, the (R)-selective SrR-TA remained active at higher DMSO co-solvent concentrations up to 30%, enabling elevated substrate concentrations for aromatic amines of low water-solubility. The kinetic parameters of the novel PpS-TA and SrR-TA in KRs of several racemic 1-arylethane-1-amines (±)-2a-d and pyruvate (co-substrate) revealed superior catalytic efficiencies (kcat values) compared to the well-characterized (S)-TA from Chromobacterium violaceum (CvS-TA) indicating the biocatalytic potential of the two newly characterized TAs.

Open bottom mesons and upsilon states in hot magnetized strange hadronic matter

The masses of open bottom mesons ([Formula: see text]([Formula: see text],[Formula: see text]), [Formula: see text]([Formula: see text],[Formula: see text]), [Formula: see text]([Formula: see text], [Formula: see text])) and upsilon states ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]) are investigated in the isospin asymmetric strange hadronic medium at finite temperature in the presence of strong magnetic fields using a chiral effective Lagrangian approach. Here the chiral SU(3) Lagrangian is generalized to include the bottom sector to incorporate the interactions of the open bottom mesons with the magnetized medium. At finite temperature, the number density and scalar density of baryons are expressed in terms of thermal distribution functions. For charged baryons, the magnetic field introduces contribution from Landau energy levels. The masses of the open bottom mesons get modified through their interactions with the baryons and the scalar mesons, which undergo modifications in a magnetized medium. The charged [Formula: see text], [Formula: see text] mesons have additional positive mass shifts due to Landau quantization in the presence of the magnetic field. The medium mass shift of the upsilon states originates from the modification of the gluon condensates simulated by the variation of dilaton field ([Formula: see text]) and a quark mass term in the magnetized medium. The open bottom mesons and upsilon states experience a mass drop in the magnetized medium. The masses of these mesons initially increase with a rise in temperature, and beyond a high value of temperature, their masses are observed to drop. When the temperature is below 90[Formula: see text]MeV, the in-medium masses of the mesons increase with an increase in the magnetic field. However, at high temperatures (T > 90 MeV), the masses are observed to drop with an increase in the magnetic field. These in-medium modifications can have observable effects in asymmetric heavy-ion collisions experiments.

TitaniQ temperatures and textural analysis as a record of the deformation history in a major continental shear zone system, Borborema Province, Brazil

We combine quartz textural analysis with Titanium-in-quartz (TitaniQ) geothermometry to investigate the late stages of deformation in mylonitic rocks from the Sucuru dike swarm in the Borborema Province. The wide range in TitaniQ temperatures (>340 to 740 °C) closely related to grain sizes are attributed to inefficient Ti resetting during bulging (BLG) and subgrain rotation (SGR) recrystallization. The highest temperature values (>500–740 °C) occur in the core of quartz ribbons and porphyroclasts. They are interpreted as the record of early-stage plastic deformation, likely during the intrusion of magmatic bodies, and are progressively overprinted during a lower-temperature stage (>340–500 °C) associated with intense dynamic recrystallization and production of a large amount of fine-grained matrix. The dominantly weak crystallographic preferred orientations (CPOs) can be attributed to a large variety in crystallographic orientations of parent grains, which control to a large extent the CPO evolution of daughter grains, and to activation of multiple slip systems in the <a > direction (basal, rhomb and prism) due to synkinematic temperature decrease. The CPOs are consistent with strain localized by operation of dislocation creep-accommodated grain boundary sliding (DisGBS) during the low-temperature stage. DisGBS seems to be less important in coarse pure quartz domains, where moderate to strong CPOs indicate the dominance of dislocation creep. Several evidence of intracrystalline deformation in quartz ribbons and porphyroclasts point to dominant activation of dislocation creep at the early high-temperature stage of deformation, with activation of prism <c>. The dike orientations, geometry and evidence of solid-state deformation in their margins, fit well with progressive E-W dextral shearing, where they intrude and crystallize in a NW-SE direction and rotate clockwise during shearing. This implies that the dextral shear regime that dominated the Borborema province from ca. 600 Ma was still in effect into the Cambrian some 60–70 million years later.

Formation and Stability Analysis of La (III), Er (III) Ho (III) Lomatiol Chelate Complexes

The studies are carried out pH-metrically in which an interaction of trivalent metal cations La (III), Er (III) and Ho (III) under the specific conditions of thermodynamics were done, where the complex formation was achieved within ionic strength consistency and making an infinite dilution where a single mole of trivalent metal, was made to react with 02 moles of lomatiol. The formation constant in stepwise values showed no measurable difference at room temperature, but the complex formation may decline above &gt;400C, as complex stability decreases at high temperature values. The chelate complex formation had been observed as a spontaneous process in solution with the obtained value of ΔG as a negative in all lomatiol metal systems. The observed positive value of change in entropy in all experimental study systems and minus values of free energy also justifies the spontaneity of the reaction. The stepwise formation rate constants (k1&gt; k2&gt; k3) showed a continuous fall in trivalent metal-lomatiol systems assigning the system formation as a normal complex formation.

Multivariate Statistical Analysis of the Phytoplankton Interactions with Physicochemical and Meteorological Parameters in Volcanic Crater Lakes from Azores

This study aimed to identify the key factors influencing the phytoplankton development in four lakes on the island of São Miguel (Azores). We used a multivariate analysis of biological parameters (phytoplankton), physicochemical parameters, and meteorological data. Data were collected between 2003 and 2018 in the volcanic Lakes of Sete Cidades (Green and Blue), Fogo, and Furnas. The ecosystems of these bodies of water are increasingly vulnerable to anthropogenic activities (increasing human pressure) as well as to changing climate patterns. This analysis is the first exploratory approach to this dataset to explore trends and patterns of evolution from a multivariate perspective. This approach is also intended to improve understanding of the conditions that favor the emergence of different Cyanobacterial divisions. For this purpose, several statistical and chemometric methods were used, such as analysis of variance (ANOVA) and principal component analysis (PCA). Multivariate models combining biological and meteorological data focused from 2010 to 2012. The results from the PCA models showed that the abundance of Bacillariophyta, Dinophyta, and Cryptophyta phyla are correlated and appear to be influenced by high levels of precipitation, evaporation, and wind speed. On the other hand, the Cyanophyta, Chlorophyta, and Chrysophyta phyla appear to be more correlated with high values of air temperature, water temperature, and radiation. Also, the Euglenophyta phylum appears to be associated with low levels of precipitation, evaporation and wind speed, and high temperatures. Finally, we can conclude that these lakes have endured physicochemical parameters over the past 15 years, meaning that the measures adopted to monitor and protect the lakes are effective.

Effects of Refining and Petrochemical Effluents on Water Quality and Zooplankton Community in River Rido Kaduna, Nigeria

Kaduna Refining and Petrochemical Corporations (KRPC) discharges were studied for a year along the river Rido to determine their impact on water quality and the distribution and abundance of Zooplankton. Physical and chemical parameters were measured following American Public Health Association (APHA) standards for evaluating wastewater. An atomic absorption spectrometer (AAS) was utilized for heavy metal analysis. For this experiment, we used a Plankton net with a 25 m mesh size and a specimen bottle with a 10 cm diameter ring opening to collect zooplankton. Zooplanktons were identified using a standard key and a monograph. Water quality parameters fluctuated, but all were within acceptable ranges except for temperature, conductivity, Total Dissolved Solid, and lead. Zooplanktons were represented in order of abundance by 8 species of protozoa constituting 72.44%, followed by 12 species of Rotifera (10.58%), followed by 13 species of Cladocera 9.55% and then 6 species of Copepoda (7.44%). The planktons showed seasonal variation with high density recorded during the wet season in all the stations. There was a low density of zooplankton in station B, while high density was observed in stations A and D. Also, the low transparency and dissolved oxygen (DO) as well as high mean values of temperature (30.88 oC), chloride (31.88 mg/L), lead (0.099 mg/L), TDS (224.17 mg/L) and conductivity (334.28 µS/cm) observed were above FEPA limits at station B were an indication of pollution and deterioration of water quality. This research revealed that the effluent discharge from KRPC has adverse effects on the zooplankton community and the water quality of river Rido.

Removal of organic pollutants (pharmaceuticals and pesticides) from sewage sludge by hydrothermal carbonization using response surface methodology (RSM)

AbstractBACKGROUNDConventional wastewater treatment plants (WWTPs) cannot degrade completely emerging pollutants such as pharmaceuticals and pesticides. The release of such contaminants through WWTP effluents or sludge disposal is of high environmental concern. Hydrothermal treatment has been adopted as alternative treatment technology for sludge to recover energy and valuable products. This study demonstrates the removal of inherent concentration levels of organic pollutants from the previous classes under variable reaction conditions, i.e. temperature, reaction time and sludge‐to‐water (%wt) ratio.RESULTSResponse surface methodology (RSM) was applied to model removal efficiency for the sum of detected pharmaceutical compounds and to evaluate the significant operational parameters. The results showed that higher values of temperature and time enhanced the percent degradation efficiency while sludge‐to‐water (%wt) ratio was not a significant factor affecting the removal process. The maximum removal efficiency of pharmaceutical residues reached 89.8% under the following conditions: 220 °C, 360 min reaction time, 7.50%wt sludge‐to‐water ratio. Additionally, hydrothermal treatment removed completely trace levels of detected pesticides, regardless of the applied conditions. RSM was also applied separately to those pharmaceuticals (i.e., amisulpride and amitriptyline) detected most frequently and at higher concentrations in sludge samples. Both compounds have been degraded at &gt;90% using reaction temperatures from 205 to 220 °C and reaction time between 297 and 360 min with 7.5% sludge/H2O ratio.CONCLUSIONHydrothermal treatment is a suitable and promising technology for sewage sludge treatment for the efficient destruction of organic pollutants and the production of renewable hydrochars. © 2022 Society of Chemical Industry (SCI).

Influence of Weather Conditions on the Spread of Fires in the Forest Fund of Zhytomyr Polesia

Fires are one of the critical factors in the weakening of forests. Given the high share of pine forests in the Zhytomyr Oblast, the conditions for fires are very favourable. Especially intense fires occurred in 2020, when rapid warming occurred in the spring, which in the absence of snow cover and the presence of intense winds in the February-March 2020 increased the fire danger in forests. The purpose of this study is to identify the features of the dynamics of the spread of fires in the forest stands of the Zhytomyr Oblast Department of Forestry and Hunting and assess the meteorological indicators that may affect their spread. Research methods: statistical – when analysing data on meteorological indicators and materials for accounting for forest fires. The study identified the specific features of the dynamics of fire spread in forest stands of Zhytomyr Oblast in 2014-2021. According to the analysis, there was a considerable increase in the number and area of fires in 2020 compared to the average figures for 2014-2019 and 2021 combined. During 2014-2021, 951 fires occurred on a forested area of 43,807.65 hectares. It was revealed that only 448 fires occurred in 2014-2019 and 2021, and 503 fires were recorded in 2020 on an area of 43,229 hectares. Among others, crown fires were recorded on an area of 6,389 hectares in the same 2020 year and on an area of 35.7 hectares in 2019 alone. The largest areas of crown fires were recorded on the territory of the State Enterprise “Ovrutske SF”, State Enterprise “Luhynske forestry”, State Enterprise “Ovrutske forestry” and State Enterprise “Slovechanske forestry”. The indicators of temperature, precipitation, and hydrothermal coefficient for 2014-2021 are analysed. The values of air temperature and precipitation were determined during the growing season, and the hydrothermal coefficient was calculated according to G.T. Selyaninov. The study established that the sum of air temperatures during the growing season was 3,127.6°C on average for 2014-2021. The highest temperature values were recorded during the growing season of 2018. According to the analysis of the amount of precipitation for the growing season 2014-2021, the indicators were set at 323.8 mm. The lowest precipitation rates were recorded in 2015. According to the ratio of temperature and precipitation indicators, the value of G.T. Selyaninov’s hydrothermal coefficient for the growing seasons of 2014-2021 was obtained, the average value of which was 1.04 units

Natural Gas Conversion and Organic Waste Gasification by Detonation-Born Ultra-Superheated Steam: Effect of Reactor Volume

The pulsed detonation (PD) gun technology was applied for the autothermal high-temperature conversion of natural gas and atmospheric-pressure oxygen-free allothermal gasification of liquid/solid organic wastes by detonation-born ultra-superheated steam (USS) using two flow reactors of essentially different volume: 100 and 40 dm3. Liquid and solid wastes were waste machine oil and wood sawdust, with moisture ranging from 10 to 30%wt. It was expected that decrease in the reactor volume from 100 to 40 dm3, other conditions being equal, on the one hand, should not affect natural gas conversion but, on the other hand, could lead to an increase in the gasification temperature in the flow reactor and, correspondingly, to an increase in the product syngas (H2 + CO) quality. The PD gun was fed by natural gas–oxygen mixture and operated at a frequency of 1 Hz. As was expected, complete conversion of natural gas to product syngas in the PD gun was obtained with H2/CO and CO2/CO ratios equal to 1.25 and 0.25, irrespective of the reactor volume. Liquid and solid wastes were gasified to H2, CO, and CH4 in the flow reactors. The steady-state H2/CO and CO2/CO ratios in the syngas produced from waste machine oil were 0.8 and 0.5 for the 100-dm3 reactor and 0.9 and 0.2 for the 40-dm3 reactor, respectively, thus indicating the expected improvement in syngas quality. Moreover, the maximum mass flow rate of feedstock in the 40-dm3 reactor was increased by a factor of over 4 as compared to the 100-dm3 reactor. The steady-state H2/CO and CO2/CO ratios in the syngas produced from the fixed weight (2 kg) batch of wood sawdust were 0.5 and 0.8 for both reactors, and the gasification time in both reactors was about 5–7 min. The measured H2 vs. CO2 and CO vs. CO2 dependences for the syngas produced by the autothermal high-temperature conversion of natural gas and atmospheric-pressure allothermal gasification of liquid/solid organic wastes by USS at f = 1 Hz were shown to be almost independent of the feedstock and reactor volume due to high values of local instantaneous gasification temperature.

High-resolution transmission spectroscopy study of ultra-hot Jupiters HAT-P-57b, KELT-17b, KELT-21b, KELT-7b, MASCARA-1b, and WASP-189b

Ultra-hot jupiters (UHJs) are giant planets on short orbital periods with high equilibrium temperature (Teq) values. Their hot, extended atmospheres are perfect laboratories for transmission spectroscopy studies based on high-resolution spectrographs. In recent years, a variety of atoms and molecules were found in their atmospheres, using different methods such as cross-correlation or transmission and emission spectroscopy. Here, we present the studies of six ultra-hot Jupiters: HAT-P-57b, KELT-7b, KELT-17b, KELT-21b, MASCARA-1b, and WASP-189b, based on high-resolution observations obtained with HARPS-N and HARPS spectrographs. By applying line and cross-correlation transmission spectroscopy methods, we searched for the absorption features of a broad range of atomic and molecular species. We did not detect any absorption features in our sample of UHJs, with the exception of WASP-189b, for which we detected Fe I, Fe II, and Ti I using cross-correlation. The transmission spectroscopy of single lines for WASP-189b revealed several absorption features (including Hα, Hβ, and Ca H&amp;K), but they remain tentative pending a better modeling of the gravity darkening deformation of the Rossiter-McLaughlin effect. The non-detections with regard to the rest of the planets can be explained via a combination of stellar pulsations and the Rossiter-McLaughlin effect, which mask possible planetary signals for most of the planets, and by the low signal-to-noise ratios of the observations for KELT-21b. Here, we compare our results with the known population of planets for which atmospheric detections have been reported in the literature. We find that the empirical frontier between hot and ultra-hot planets, based on the detection of atomic and ionized species in their atmospheres, can be established as Teq = 2150 K.

Recent advances on the stability of dietary polyphenols

Recent advances on the stability of dietary polyphenols

Robust quantum entanglement and teleportation in the tetrapartite spin-1/2 square clusters: Theoretical study on the effect of a cyclic four-spin exchange

The whole entanglement measure so-called geometric Π4 average of tangles and bipartite entanglement of the antiferromagnetic spin-1/2 XXX Heisenberg model on a tetranuclear square cluster with cyclic four-spin interaction are rigorously examined by the help of thermal negativities. The model comprises two nearest-neighbor exchange couplings J1 and J2 such that J1≫J2. When the cyclic four-spin exchange is zero, the maximum value of whole entanglement Π4 is achieved at low enough temperatures and relatively high magnetic fields (B≈J1). Also, maximum bipartite entanglement between pair spins with exchange coupling J1 is achievable at high temperature and high magnetic field. This quantity remains alive for sufficiently high temperature and high magnetic field values comparable with the relevant exchange coupling J1. A nonzero value of the cyclic four-spin exchange notably enhances the degree of the whole entanglement, while it weakens the bipartite entanglement degree. We demonstrate that the whole entanglement reaches an unconventional minimum at a special parameter region of cyclic four-spin exchange almost ten order of magnitude smaller than J1, where the system is in a quantum antiferromagnetic state. The real complex [Cu4L4(H2O)4](ClO4)4 as a strong antiferromagnetic tetranuclear square compound provides us an experimental representative to estimate the strength of the whole and bipartite entanglements at high enough temperature. It is demonstrated that the entanglement negativities of this complex are yet depend on the considered cyclic four-spin interaction even though its magnitude is significantly smaller than J1. We realize that the possibility of quantum teleportation through a couple of discrete Cu4II complexes would solely happen for the magnetic fields lower than a critical value. It is also demonstrated that enhancing the cyclic four-spin exchange results in diminishing the average fidelity. Moreover, we conclude that the quantum Fisher information investigated for the pair of spins with exchange interaction J1 reaches its minimum close to the critical magnetic field at which a ground-state phase transition occurs from highly entangled state to separable one.

Hydrocarbon pollution in the waters and sediments of the Kerch Strait

The results of studying the content and composition of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons in the suspended particulate matter of surface waters and in the surface layer of bottom sediments in 2019–2021 in the Kerch Strait in comparison with earlier studies in other areas of the Black Sea (Theodosia Gulf, Tuapse area, Coastal waters of the Crimean Peninsula, Big Sochi, Central part of the Sea) are presented. Despite the high concentrations of aliphatic hydrocarbons (especially in the waters of the strait itself: 28–254 on average 87 μg/L. The highest content of aliphatic hydrocarbons was confined to the cross-section through the Kerch Strait. Accumulation of aliphatic hydrocarbons, as well as the suspended particulate matter, occurs in the western part of the Strait, which is associated with the predominant wind direction and coastal orography. The composition of alkanes did not correspond to the smooth distribution of homologues characteristic of oil. Their distribution was bimodal in most samples, which may indicate a mixed genesis of alkanes. Among the low-molecular-weight alkanes either even numbered autochthonous alkanes n-C16, C18, C22, arising during the microbial transformation of aliphatic hydrocarbons, or n-C17, indicating the inclusion of phyto- and zooplankton alkanes, prevailed. Despite the different sources of hydrocarbons input, the distribution of the total concentrations of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons basically coincided. Polycyclic aromatic hydrocarbons composition was dominated by fluoranthene and pyrene, which are formed in high-temperature combustion processes Low values of the Σnaphthalenes/Phen ratio (0.05–0.11) may indicate an insignificant inclusion of petroleum polyarenes.In contrast to suspension of surface waters, the highest content of hydrocarbons in the surface sediments was found not in the strait, but at stations in areas with aleurite-pelitic sediments, which is due to the pattern of currents in these areas and the higher sorption capacity of finely dispersed sediments. The average Corg content in July 2020, was 1.8 times lower (0.34%) than in September 2019 (0.63%), and aliphatic hydrocarbons, on the contrary, was 2.2 times higher (47 μg/g) than in April 2019 (21 μg/g). In surface sediments the maximum concentration of aliphatic hydrocarbons was established in July 2020 (233 μg/g), and the highest average content in July 2021 (58 μg/g). This area is also associated with higher concentrations of aliphatic hydrocarbons in the composition of Corg –≥1%. The composition of alkanes in surface sediments differed from their composition in suspension. The ratio of low-to-high molecular weight homologues (L/H = 0.08–0.54) was lower and the odd-to-even ratio (CPI = 1.19–4.58) was higher than in particulate matter. Due to the coarse composition of sediments, the content of polycyclic aromatic hydrocarbons in their surface layer was lower (0–631 ng/g) compared to other areas of the Black Sea. In their composition, along with fluoranthene and pyrene, methylated naphthalene homologues also belonged to the dominant compounds. Correlation analysis of individual polyarenes, as well as factor analysis, indicates their mixed genesis oil + pyrogenic, with the preference of the latter in most samples. The entry of pollutants into the marine environment increases the hydrocarbons content in water and bottom sediments, creating a modern hydrocarbon background.