Higher Temperature Values Research Articles

Exploration of quantum oscillation in antiferromagnetic Weyl semimetal GdSiAl.

GdSiAl single crystal has been investigated by means of magnetic and magneto-transport measurements and compared with ab-initio density functional theory (DFT) calculations. Significant non-saturating magnetoresistance reaching ∼ 18% at 12T and 2K was observed, alongside the presence of Shubnikov-de Haas oscillations with the fundamental frequencies 22.09T and 77.33T. Shubnikov-de Haas oscillations provide the information about the nontrivial π Berry phase in GdSiAl with the Fermi surface areas of 0.00211 Å-2and 0.00739 Å-2. Angle-dependent magnetoresistance shows anisotropy with θ, exhibiting a maximum at 180°. The magnetic susceptibility data for H ∥ c and H ⊥ c reveals that the magnetic moments of Gd3+ions orders antiferromagnetically below 32K along with an another transition occurs at ∼ 8K, which is consistent with the heat capacity measurements where a distinct λ-shaped anomaly has been observed near antiferromagnetic ordering temperature 32K. The high value of Debye temperature indicates the contribution of acoustic phonons. Electronic structure calculations suggest the existence of nested Fermi surface pockets characterized by nesting wave vectors that closely align with the observed magnetic ordering wave vector. Furthermore, DFT calculations reveal the presence of Weyl nodes in close proximity to the Fermi surface. Our findings from combined experimental and theoretical techniques indicate GdSiAl to be a potential candidate for an antiferromagnetic topological Weyl semimetal.

The design of a combustion chamber operated in MILD regime - numerical modeling of hydrogen combustion in oxygen steam mixtures

The goal of the current work is to develop a combustion chamber that can operate on recirculated steam produced by burning hydrogen in oxygen under conditions of Moderate or Intense oxygen Dilution (MILD) in atmospheric and stoichiometric conditions. The study investigates several configurations of combustor with nozzles, taking into account the overall temperature, OH radicals, and heat release rate distribution throughout the combustor’s domain. Thermal power variations of the steam generator (5 to 20 kW) were examined in conjunction with different oxygen dilutions with steam, down to 3% of O2 (by mol.). The outcomes reveal that a rise in dilution degree promotes a drop in the mean temperature across every case and reagents’ recirculation with homogeneous temperature field, suggesting the presence of MILD combustion. The highest temperature values were observed at the stoichiometric mixture fraction. Higher dilution degree revealed more efficient heat release across the domain with low fluctuations from the reference MILD combustion data. Of the two combustion models studied, the Partially Stirred Reactor model did not show flame extinction at the highest dilution degrees, unlike the Eddy Dissipation model. The selected final design of the combustion chamber was used for constructing the actual combustor dedicated for lab-scale operation.

SOFIA/EXES Observations of Warm H2 at High Spectral Resolution. II. IC 443C, NGC 2071, and 3C 391

Using the EXES instrument on SOFIA, we have obtained velocity-resolved spectra of several pure rotational lines of H2 toward shocked molecular gas within three Galactic sources: the supernova remnant (SNR) IC 443 (clump C), a protostellar outflow in the intermediate-mass star-forming region NGC 2071, and the SNR 3C 391. These observations had the goal of searching for expected velocity shifts between ortho- and para-H2 transitions emitted by C-type shocks. In contrast in our previous similar study of HH7, the result of our search was negative: no velocity shifts were reliably detected. Several possible explanations for the absence of such shifts are discussed: these include a preshock ortho-to-para ratio that is already close to the high-temperature equilibrium value of 3 (in the case of IC 443C), the more complex shock structures evident in all these sources, and the larger projected aperture sizes relative to those in the observations of HH7.

First use of Chironomid Pupal Exuvial Technique in freshwater biomonitoring in Cameroon: Ecological aspect and morphological description of Chironomidae (Insecta: Diptera)

The biodiversity of urban streams is gradually degrading as a result of anthropogenic pollution. In this study, chironomid pupal exuviae were used as surrogates to assess urban streams and a lake in Douala Cameroon. We compared these assessments with samples collected from a suburban forest stream. Based on their highly adaptive capability, we predicted that chironomid communities would present high diversity and abundance in urban habitats. Chironomid pupal exuviae were collected using the chironomid pupal exuvial technique in 14 urban and 2 forest reference stations during dry and rainy seasons. Measurements of the environmental variables were done simultaneously. Physicochemical analysis revealed that all urban sites have had very poor ecological health status whereas forest site had good water quality as shown by the hierarchical cluster analysis. This ecological survey identified 8 species/morphotypes of chironomids all belonging to the subfamily Chironominae, tribe Chironomini. These are Chironomus holomelas(?), Chironomus sp.1, Chironomus sp.2, Chironomus sp.3, Chironomus (Lobochironomus) sp., Stenochironomus sp., Dicrotendipes sp. and Dicrotendipes pulsus. No midge pupal exuviae were recorded at the forest stations (S1 & S2) and the stations S6 and S7 located downstream industrial mill effluents. The species richness of the study sites was significantly very low as compare to other Afrotropical studies. Canonical redundancy analysis revealed that high values of water temperature, ammonium, nitrates and phosphates, and low oxygen concentration were significant predictors of the distribution and high abundance of Chironomidae. This survey highlighted the impacts of anthropogenic activities on chironomid diversity and distribution, with great decrease of their diversity due to industrial pollution.

Determination and Verification of the Johnson–Cook Constitutive Model Parameters in the Precision Machining of Ti6Al4V Alloy

Numerical simulations of the cutting process play a key role in manufacturing and cost optimization. Inherent in finite element analysis (FEA) simulations is the correct description of material behavior during machining. For this purpose, various material models are used to describe the behavior of the material in the range of high deformation, high temperature values, and high strain rates. Very often the Johnson–Cook (JC) material model is used for this purpose; however, the correct determination of the material constants of this model is a key aspect. Therefore, this paper presents a procedure for determining the material constants of the JC model using an analytical method based on normalized tensile and compression testing of the material for different strain rates over a wide temperature range. After determining the material constants, the authors conducted numerical simulations of the orthogonal turning of Ti6Al4V titanium alloy using the obtained constants. Validation of the obtained results with those obtained in experimental studies was also carried out. The outcomes demonstrated that the difference between FEM simulation and experimental tests did not exceed 0.02 mm (14%) in the case of chip thickness,. Much smaller differences were obtained for the temperature in the cutting zone, where the maximum difference was about 45 °C (4%). Comparing the components of the cutting force, we found that, in the case of the main cutting force, in most cases, the differences did not exceed 70 N (8%). After the verification of the obtained results, it was also found that the determined material constants of the Johnson–Cook model can be successfully used in FEM modeling of the cutting process of Ti6Al4V titanium alloy for the adopted range of values of technological parameters.

Sintering enhancement process based on fluidity and bonding phase strength

The sintering process is influenced by complex low-grade ores. This study used seven types of imported iron ore, A–F and domestically produced iron ore, G, as raw materials to study their chemical composition, as well as the liquid fluidity and bonding strength of the mixed ore after single and optimised ore blending. The high-temperature characteristic test values of mixed ores are positively correlated with the weighted calculated values of individual ores. Under the sintering cup conditions, the optimal ore mixing includes a 9% increase in liquid fluidity and a 6% increase in bonding strength. The latter significantly improved the sintering yield and drum strength, reaching 75.89% and 65.67%, respectively. In addition, the consumption of solid fuel has slightly decreased by 0.06 kg·t−1, and the utilisation coefficient has slightly increased. In addition, the sintering yield and quality indicators of the scheme have been comprehensively improved. Compared with the benchmark scheme, through liquid fluidity optimisation, an increase in magnetite phase, a decrease in haematite, and a significant decrease in acicular calcium ferrite were observed, interwoven with magnetite. The silicate-bounding iron oxide also showed an increase in this optimisation. In the optimisation of bonding strength, the corrosive structure interwoven with magnetite and needle shaped ferrite significantly increases, while the iron oxide bound with silicate decreases. The improvement effect of liquid phase fluidity and bonding phase strength optimisation on sintering process and mineralisation behaviour was verified through sintering cup test and mineral phase analysis.

Halocins and C50 Carotenoids from Haloarchaea: Potential Natural Tools against Cancer.

Haloarchaea are a group of moderate and extreme halophilic microorganisms, belonging to the Archaea domain, that constitute relevant microbial communities in salty environments like coastal and inland salted ponds, marshes, salty lagoons, etc. They can survive in stress conditions such as high salinity and, therefore, high ionic strength, high doses of ultraviolet radiation (UV), high temperature, and extreme pH values. Consequently, most of the species can be considered polyextremophiles owing to their ability to respond to the multiple extreme conditions characterizing their natural habitats. They cope with those stresses thanks to several molecular and metabolic adaptations. Thus, some of the molecules produced by haloarchaea show significantly different biological activities and physicochemical properties compared to their bacterial counterparts. Recent studies have revealed promising applications in biotechnology and medicine for these biomolecules. Among haloarchaeal biomolecules, rare natural pigments (C50 carotenoids) and small peptides called halocins and microhalocins have attracted attention worldwide due to their effects on animal and human commercial tumoral cells, apart from the role as antibiotics described for halocins or the immunomodulatory activity reported from C50 carotenoids like bacterioruberin. This review summarizes recent knowledge on these two types of biomolecules in connection with cancer to shed new light on the design of drugs and new therapies based on natural compounds.

A mesoscopic device for a realization of the topological Kondo effect

Abstract The search for anyons is a field of immense interest owing to its potential application in the field of quantum information. Quantum critical Kondo impurities constitute one possible platform for their realization and topological Kondo effect (TKE) by virtue of remaining critical in the presence of perturbations, seems to be especially promising in this regard. In this paper we discuss practical steps for a realization of TKE with a relatively high Kondo temperature T K . Its central feature is the so-called Majorana-Cooper box (MCB) and we argue that a particular type of iron-based topological superconductor is especially suitable for realization of TKE. Once MCB is available one needs to connect it to external metallic leads to produce TKE. A relatively high value of the Kondo temperature T K is then aided by a large superconducting gap of the iron-based superconductor. We give estimates for T K , for the cases of both isotropic and anisotropic exchange couplings of MCB with the leads.

Investigation of nuclear structure and [formula omitted]-decay properties of As isotopes

The nuclear ground state properties of 67−80As nuclei have been investigated within the framework of relativistic mean field (RMF) approach. The RMF model with density-dependent (DD-ME2) interaction is utilized for the calculation of potential energy curves and the nuclear ground-state deformation parameters (β2) of selected As isotopes. Later, the β-decay properties of As isotopes were studied using the proton–neutron quasi particle random phase approximation (pn-QRPA) model. These include Gamow Tellar (GT) strength distributions, log ft values, β-decay half-lives, stellar β± decays and stellar electron/positron capture rates. The β2 values computed from RMF model were employed in the pn-QRPA model as an input parameter for the calculations of β-decay properties for 67−80As. The calculated log ft values were in decent agreement with the measured data. The predicted β-decay half-lives matched the experimental values within a factor of 10. The stellar rates were compared with the shell model results. Only at high temperature and density values, the sum of β+ and electron capture rates had a finite contribution. On the other hand, the sum of β− and positron capture rates were sizeable only at low density and high temperature values. For all such cases, the pn-QRPA rates were found to be bigger than the shell model rates up to a factor of 33 or more. The findings reported in the current investigation could prove valuable for simulating the late-stage stellar evolution of massive stars.

Preparation and performance evaluation of heat resistant and salt resistant anionic fluid loss reducer for water‐based drilling fluid

AbstractIn this investigation, a new micro‐crosslinked anionic polymer resistant to elevated temperature and high salinity, PKDASN, was synthesized using 3‐chloropropyltriethoxysilane (KMB703), N, N‐Dimethylacrylamide (DMAM), 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS), N‐vinyl caprolactam (NVCL), and sodium (4‐vinyl phenyl)methanesulfonate (SVM) employing free radical polymerization in a water‐based solution. The structure of PKDASN was analyzed using Fourier‐transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and X‐ray photoelectron spectroscopy, while its microstructure was analyzed using scanning electron microscopy. Thermogravimetric analysis showed that the pyrolysis temperature of PKDASN was above 294°C. Adding KMB703 enables the polymer to form a dense and stable spatial network. This intensified polymer network could interact with bentonite via intermolecular force and Coulomb force and form a dual grid structure, which presents impressive stability and control of filtration in saltwater. This is mainly achieved through creating a “silane coupling layer” on the particle surface by KMB703, which facilitates the crosslinking and aggregation of the polymer, thereby reinforcing the polymer's framework. This implies that under high‐temperature conditions of 230°C, 3 wt% PKDASN can improve the filtration effectiveness of drilling fluids and exhibit resistance to 15 wt% NaCl contamination. American Petroleum Institute filtration(FLAPI) and High temperature and high pressure filtration(FLHTHP) values were 4.6 and 23.0 mL, respectively. Therefore, this investigation provides a novel approach to utilizing the designated silane agent for the advancement of filtration loss additives in drilling fluids resistant to elevated temperature and high salinity.

A recipe for an effective selection of promising candidates for high-temperature superconductors among binary hydrides

Recent research on compressed binary hydrides have unveiled the potential for achieving superconductivity at near-room-temperature. Nevertheless, the available decision-making procedures standing behind the selection of constituent elements that may potentially exhibit high values of critical temperature (Tc) are far from optimal. In other words, a lot of experimental and numerical effort is wasted on exploring unpromising compounds. By conducting a deep study of a database containing over 580 binary hydride superconductors, we were able to observe some interesting relationships between Tc and selected physico-chemical properties of examined compounds. Among studied parameters, the ratio of the sum of the molecular weight of heavier atoms to the total mass of all hydrogen atoms in the chemical formula of hydride (MX/MH) was found to be the most valuable indicator that can help to screen for new promising superconductor candidates. This is because the highest Tc requires the lowest MX/MH ratio. Statistical analysis indicates a 28% chance of finding Tc > 200 K within 0 <MX/MH < 15. It is expected that these findings will not only allow for more efficient use of resources by improving future superconductor candidates selection but also they will accelerate ongoing experimental and numerical research that should bring new exciting discoveries in a much shorter time.

Knee temperature remains abnormal in patients successfully treated with anterior cruciate ligament reconstruction: An infrared thermography analysis.

The aim of this study was to evaluate if the operated knee environment remains abnormal in patients successfully treated with anterior cruciate ligament reconstruction (ACL-R). Thirty asymptomatic patients were enrolled (28 men, 2 women, age 28.6 ± 6.54 years, body mass index: 24.9 ± 3.0 kg/m2) and evaluated at 42.2 ± 12.5 months after surgery. Patients were assessed with patient-reported outcome measurements and with a triaxial accelerometer. The temperature of the knees as well as four regions of interest were evaluated with an infrared thermographic camera FLIR T1020 (FLIR® Systems) according to a standardised protocol including a baseline evaluation and further evaluations immediately after exercise and after 5, 10 and 20 min. The temperature of the ACL-R knee was compared to that of the contralateral healthy knee for the purpose of the study. The mean temperature of the knee was higher (p = 0.010) for the ACL-R knees (31.4 ± 1.4°C) compared to the healthy knees (31.1 ± 1.6°C), as well as for the patellar area (p = 0.005), the lateral area (p = 0.016) and the medial area (p = 0.014). The analysis of the response to the exercises of the ACL-R knees showed similar trends to the healthy knees but higher temperature values at all time points (p < 0.05). Patients who underwent ACL-R with concomitant meniscal treatment showed higher knee temperatures compared to ACL-R knees without concomitant meniscal treatment after 5 (p = 0.047), 10 (p = 0.027) and 20 min (p = 0.048). The temperature of asymptomatic knees previously treated with ACL-R is higher than the contralateral healthy knee, both at rest and after exercise, with a further increase in knees that underwent both ACL-R and meniscal treatment. These results suggest an inflammatory state persisting years after the surgery, which could predispose to the early onset of knee degeneration. III, Case-control study.

Empirical calibration for helium abundance determinations in active galactic nuclei

ABSTRACT For the first time, a calibration between the He i$\lambda 5876$/H $\beta$ emission line ratio and the helium abundance y = 12 + log(He/H) for Narrow line regions of Seyfert 2 Active Galactic Nuclei is proposed. In this context, observational data (taken from the SDSS-DR15 and from the literature) and direct abundance estimates (via the $T_{\rm e}$-method) for a sample of 65 local ($z \: \lt \: 0.2$) Seyfert 2 nuclei are considered. The resulting calibration estimates the y abundance with an average uncertainty of 0.02 dex. Applying our calibration to spectroscopic data containing only strong emission lines, it yields a helium abundance distribution similar to that obtained via the $T_{\rm e}$-method. Some cautions must be considered to apply our calibration for Seyfert 2 nuclei with high values of electron temperature (${\gtrsim} 20\, 000$ K) or ionization parameter ($\log U \ \gt\ {-}2.0$).

Analysis of the Processes of Paraffin Deposition of Oil from the Kumkol Group of Fields in Kazakhstan

The oil pipeline transportation of highly waxy oils when it is cold is accompanied by the deposition of paraffins in the inner surface of the pipeline. This study of the initial properties of the oil; the composition, structure, and nature of the components of normal alkanes in oil; and their influence on the aggregative stability of the resulting system makes it possible to find the best solutions to optimize the conditions of oil transportation with the lowest energy costs. This study shows that, according to the content of solid paraffin (14.0–16.2%), the oils of the Kumkol group of fields in Kazakhstan are highly waxy. They are characterized by high yield loss temperature values (+9–+12 °C), which also correlate with the values of the rheological parameters (τ0 1.389 Pa, 3.564 Pa). The influence of the temperature and shear rate on the shear stress and effective viscosity of the initial oils was studied. At temperatures below 20 °C, depending on the shear rate, there is an increase in the effective viscosity values (0.020 Pa∙s, 0.351 Pa∙s). The influence of the nature of solid hydrocarbons on the parameters of the paraffinization process and of the intensity of the paraffinization of the metal surfaces was studied. Our study shows that the main share of n-alkanes in the Kumkol and Akshabulak oils falls on paraffins of the C15–C44 group. The greater the temperature difference between the oil and the cold steel surface (≤40 °C), the lesser the amount of asphalt–resin–paraffin deposits (ARPDs) that fall out on the surface of the rod, although the content of long-chain paraffins prevails in these ARPDs. At the same time, the consistency of the released asphalt–resin–paraffin deposits (ARPDs) becomes denser, which makes their mechanical removal more difficult. Furthermore, the results of this study of the cooling rate shows that the rapid cooling of oils leads to the formation of a large number of crystallization centers, which leads to an increase in the values of the yield loss temperature and kinematic viscosity of the oils.

Strain Effect on Optoelectronic and Thermoelectric Properties of the Perovskite NaGeI3

In this research, we investigate the impact of strain on the optoelectronic and thermoelectric properties of the NaGeI3 perovskite by employing a combination of density functional theory (DFT) and Boltzmann transport theory. Initially, we examine the NaGeI3 material’s structural, electronic, and optical properties using the generalized gradient approximation (GGA). The results reveal that this material proves the behavior of a semiconductor with a p-type character and possesses interesting optical properties. Furthermore, we outline the thermoelectric properties of the material, including the Seebeck coefficient, the electrical and thermal conductivities, the figure of merit (ZT), and the power factor (PF). Our investigations indicate that the Seebeck coefficient exhibits positive and increasing values with the application of strain. This confirms the p-type semiconductor behavior observed in the studied material. Additionally, the NaGeI3 compound demonstrates significantly high values of the ZT when compared with the existing thermoelectric materials, both at room and high-temperature values. This suggests that the NaGeI3 compound stands as a promising potential candidate for optoelectronic and/or thermoelectric applications.

Change in the distribution of heavy 1 h precipitation due to temperature changes in measured values, model reanalyses and model simulations of future climate

This article presents main results on how the 1 h precipitation distribution changes, focused on high percentiles, with increasing air temperature based on the data from the Czech territory. The air temperature, the dew point temperature (both measured at 2 m above ground) and the temperature of lifting condensation level are used as temperature characteristics. The change in the distribution of 1 h precipitation measurements is compared with the results of reanalyses based on simulations of numerical weather prediction model ALADIN-CZ and with the results of future climate simulations by climate model ALADIN-CLIMAT-CZ. In general, the increase in precipitation appears clearly in the very upper part of precipitation distribution for high percentiles. Values of the upper percentiles of precipitation increase up to a certain threshold temperature and then decrease, which is also found in other studies. This also applies to the simulations of future climate. The main difference in measured and model results appears at the highest temperature values, which may be implied by the very different number of the model and the measured data.

Пространственная реконструкция климата востока Азии в раннем эоцене

Using the Coexistence Approach, climatic zones were identified for the Early Eocene of East Asia. Data for reconstruction include 48 palynofloras from the East Asia's Lower Eocene continental deposits from 75° to 19° N. The climatic inferences obtained are consistent with global trends, showing high values of mean annual temperature (MAT) and mean annual precipitation (MAP). According to our results, there is a weakly expressed latitudinal temperature gradient from the north to the south, showing an increasing trend for MAT values, while a very weakly expressed latitudinal gradient of precipitation demonstrates a decreasing trend for MAP values. Based on MAT and MAP values, three regional climatic zones are distinguished. The warm moderate climate zone (north of ≈ 55° paleolatitude) is characterized by low values for temperature (14.2-16.2 °C) and high ones for precipitation (1158-1334 mm). In the transition zone (≈ 45-55° paleolatitude), MAT values vary from 15.9 to 19.0 °C, and MAP values range from 874 to 1352 mm. The subtropical climate zone (south of ≈ 45° paleolatitude) is characterized by high values for temperature (16.5-19.1 °C) and low, for precipitation (874-1263 mm).

Demarcation of suitable site for solar photovoltaic power plant installation in Bangladesh using geospatial techniques

The major goal of this research is to adopt analytical hierarchy process (AHP) based geospatial technique to select suitable zone for the solar photovoltaic (PV) power plants. Nine thematic layers altogether—slope, global horizontal irradiation (GHI), relative humidity, direct normal irradiation (DNI), elevation, distance from major roads, distance from protected areas, rainfall, and land use/land cover (LULC)—are combined through overlay analysis in ArcGIS to create the final map of suitability for the placement of solar photovoltaic (PV) power plants in Bangladesh. This map has been classified into five categories namely, restricted zone, less suitable zone, moderate suitable zone, good suitable zone, and excellent suitable zone. These categories are covered by 7.28%, 16.61%, 28.51%, 27.77%, 21.83% land of total area in Bangladesh respectively. The findings of this research have been presented that ‘the excellent suitable’ and ‘good suitable’ areas for the construction of solar power plants are in the western and northwestern part (Rajshahi, Pabna, Sirajganj, Natore, Naogaon, Chapainawabganj, Bogura, Faridpur, Jessore, Jehenaidha, Magura, Kushtia, Choudanga, Meherpur) of the study area which contain a high value of global horizontal irradiation, direct normal irradiation, elevation and low value of slope, rainfall, temperature, relative humidity. Besides the restricted and less suitable zone for installing solar photovoltaic (PV) power plants indicates a high value of rainfall, slope, temperature, relative humidity and low value of global horizontal irradiation, direct normal irradiation, and elevation. Bangladesh's currently operational solar plants were taken into consideration for this study's validation purposes. The proposed framework may potentially be used in different locales on a national and worldwide scale. This study offers a consistent GIS process for the accurate, inexpensive implementation of a solar energy plan to achieve environmentally friendly goals.

Starch spectra of Ampelopteris prolifera (Retz.) Copel, a new addition to the existing lexicon and its comparison with a local potato cultivar (Solanum tuberosum L. cv. Kufri Jyoti)

Novel kinds of starch spectra were generated from a lesser-known plant, making this investigation unique. The recent trend of starch characterization shows the establishment of novel bioresources from nonconventional unexplored databases. The present endeavor was made to obtain the starch fingerprint of Ampelopteris prolifera (rhizome) belonging to seedless vascular plants. For comparison, a commercial local cultivar of potato (Kufri Jyoti) was taken. The starch particle of A. prolifera shows much uniqueness depicting its novelty viz., crystallinity index of 60.04 %, powder diffractogram at (2θ scale)17.57° to 39.78°; this diffractogram pattern is reported from this study as newer one i.e. R type(whereas potato starch is CB type); characteristic peak at 2θ = 20.07° suggests starch-lipid complex formation and V type crystallinity (i.e. RS 5 type); FTIR spectra showing the presence of more short chain branching; high gelatinization temperature(84.62 ± 0.10), particle size and zeta value of A. prolifera is 4.00 ± 0.81 μm and − 18.91 ± 3.58 mV respectively. Bragg's peak from the single crystal X-ray diffraction has been generated for the first time of A. prolifera. Extraction of the starch particle was performed in chilled water. Therefore, the present study suggests wide-spectrum commercial utility and cost-effective production.

Influence of geotemperature conditions on the oil and gas potential of the South Caspian depression (the case of the Lower Kura depression and Baku archipelago)

&#x0D; &#x0D; &#x0D; In the article, the oil and gas potential of the deep-lying sediments of the Lower Received in revised form 13.08.2023; Kura depression and the Baku archipelago, which are geostructural elements of the South Accepted 13.11.2023 Caspian depression, are investigated according to the geotemperature conditions. The main aim of the research is identifying the oil-gas «windows» in the 22-24 km thick sedimentary rock complex of the South Caspian depression based on the geothermal factor. Using temperature values measured at different depth sections in different structures of the Lower Kura depression and Baku archipelago, temperature distribution maps of the area and a graph of changing temperature by depth were constructed. According to the geothermal maps constructed for the Lower Kura depression, a relatively high temperature value is observed in the north-west part of the area. This anomalous value is related to the location of active, periodically erupting mud volcanoes, which play an important role in temperature distribution, as well as local uplifts, which are more complicated by tectonic landslides and upthrusts. At great depths (5,500-6,500 m) within the research region, almost everywhere, anomalously high pore and reservoir pressures are observed, which create the conditions for the manifestation of tectonic-physical processes and the generation of great energy affecting the oil and gas potential of the area. In all the geotemperature maps constructed for different depth intervals in the Baku archipelago, high temperature values are observed in the north zone where the Sangachal-deniz-Duvanni-deniz-Khara-Zira island and Alat-deniz structures are located. This is due to the complication of uplifts by active mud volcanoes, which play an important role in the formation of local heat sources. The Khara-Zira island mud volcano, the largest in the Baku archipelago, is also located here. Based on the analysis of the temperature values in the research areas, a decrease in the temperature values is observed due to increase in the thickness and the clay content of the sedimentary layer in the direction from the Lower Kura depression to the South Caspian basin. The temperature is 990C at 5,000 m in the Lower Kura depression, 900C in the Baku archipelago. So, a decrease in temperature is characteristics for all depths. The analysis of the compiled graphs shows that the top of the main zone of oil formation in the Lower Kura depression starts at a depth of 2,000-2,500 m, and the lower limit is located at a depth of about 9,000 m (1500 C). The top of the main zone of oil formation in the Baku archipelago starts at a depth of 3,000 m, and the lower limit is located at a depth of 9,000-11,000 m. So, it shows that as the oil and gas formation sources the potential oil source rocks in the Lower Kura depression and the Baku archipelago at the depth range from 2,000-2,500 m to 8,000-11,000 m can produce industrially important oil and gas.&#x0D; &#x0D; &#x0D;