Gradual Increase In Temperature Research Articles

Effects of Elevated Seawater Temperatures on Cellular Immune Function in the Top Shell, Turbo sazae

The top shell, Turbo sazae, occurs commonly in the shallow rocky subtidal area of Jeju Island off the south coast of Korea, and it is one of the most valuable gastropod resources supporting the local shellfish industry. T. sazae landings in Jeju have declined dramatically in recent years, although the factors involved in this decline are yet to be identified. Recent studies also have reported that T. sazae is expanding its distribution range to the east coast of Korea, possibly due to the increasing seawater temperature. In this study, we investigated the hemocyte responses of T. sazae to elevated seawater temperatures in order to gain a better understanding of its immunological response to higher water temperatures. In this experiment, we exposed top shells to a gradual increase in seawater temperature, ranging from 22 °C to 30 °C, over a span of 9 days. We employed flow cytometry to assess various cellular immune responses, including hemocyte viability, phagocytosis capacity, and the production of reactive oxygen species (ROS) in T. sazae. The results showed that top shells exposed to elevated seawater temperature exhibited a significant decrease in phagocytosis capacity and an increase in ROS production after 3 days of the experiment. These findings indicate that an elevated seawater temperature imposes a stressful condition on T. sazae, characterized by reduced phagocytosis capacity and increased oxidative stress.

Calibrating lower-middle Miocene mammal faunas and unravelling climate change during the Miocene Climate Optimum: the Bardenas Reales de Navarra record (Ebro basin, NE Iberian Peninsula)

AbstractThe chronology of lower Miocene Iberian small mammal faunas is still poorly constrained given the scarcity of well dated sedimentary successions including small mammal fossil localities. Such scarcity has prevented also an accurate understanding of the response of European terrestrial ecosystem to global changes across the Miocene climate optimum (MCO), one of the best analogues of present-day global warming. Here we present an updated fossil small mammal record of the Bardenas Reales de Navarra (western Ebro basin, Spain), where an expanded lower to middle Miocene continental succession is superbly exposed. Previous and new magnetostratigraphic results from this succession have enabled us to propose, along with additional magnetostratigraphically-dated Iberian faunas, a new chronology for local zones Y to D (Mammal Neogene zones MN2 to MN5). In addition to that, the studied small mammal faunas point to a gradual increase in temperature and humidity conditions in SW Europe between 20 and 15.5 Ma, which appears to be coupled with the progressive shift towards warmer regional (Atlantic) and global conditions across the MCO, thereby pointing to gradual changes in oceanic circulation as the main driver of this period of global warmth. The evolution of sedimentary facies appears to indicate a threshold response of the Ebro basin hydrological balance to the MCO, whereas pedogenic formation of magnetic minerals seems to be linked to periods of enhanced climate variability. These results highlight the need of combining different paleoenvironmental indicators in order to obtain a reliable view of the response of continental ecosystems to global warming.

Importance of environmental signals for cardiac morphological development in Atlantic salmon.

The hearts of salmonids display remarkable plasticity, adapting to various environmental factors that influence cardiac function and demand. For instance, in response to cold temperature, the salmonid heart undergoes growth and remodeling to counterbalance the reduced contractile function associated with dropping temperatures. Alongside heart size, the distinct pyramidal shape of the wild salmonid heart is essential for optimal cardiac performance, yet the environmental drivers behind this optimal cardiac morphology remain to be fully understood. Intriguingly, farmed salmonids often have rounded, asymmetrical ventricles and misaligned bulbi from an early age. These deformities are noteworthy given that farmed salmon are often not exposed to natural cues, such as a gradual temperature increase and changing day lengths, during critical developmental stages. In this study, we investigated whether natural environmental conditions during early life stages are pivotal for proper cardiac morphology. Atlantic salmon were raised under simulated natural conditions (low temperature with a natural photoperiod; SimNat) and compared with those reared under simulated farming conditions (SimFarm). Our findings reveal that the ventricle shape and bulbus alignment in SimNat fish closely resemble those of wild salmon, while functional analyses indicate significant differences between SimNat and SimFarm hearts, suggesting diastolic dysfunction and higher cardiac workload in SimFarm hearts. These findings highlight the profound influence of environmental factors such as water temperature and photoperiod on the structural development of the salmonid heart, underscoring the importance of early environmental conditions for cardiac health.

Study on the influence of heat treatment process on the microstructure and hardness of carburized layer of 20CrMoH steel

Abstract In this paper, the effects of different carburizing quenching processes and tempering processes on the depth of the hardened layer and microstructure of 20CrMoH were studied by means of hardness analysis and SEM microstructure analysis. The results show that: when the quenching temperatures in the range of 820-880 °C, it has little effect on the depth of the hardened layer. And the hardness value at the same depth is at a considerable level, which is not affected by the quenching temperature. When the tempering temperature range is 150-280 °C, the tempering temperature has a great influence on the depth of hardened layer. And with the gradual increase of tempering temperature, the depth of hardened layer decreases gradually. Also the hardness value at the same depth from the edge shows a monotonous decreasing trend with the gradual increase of tempering temperature.

Influence of Applied Discharge Voltage and Gas Flow Rate on Nickel Plasma Jet Parameters Diagnosed by Optical Emission Spectroscopic Technique

Abstract: In this work, we measure the plasma parameters by using an AC high-voltage power supply that generates a non-thermal plasma jet system at atmospheric pressure. A nickel (Ni) metal strip, with dimensions of 1.5 × 10 cm2, was connected to the anode electrode of the AC power supply. This nickel strip was immersed in a flask with a small amount of distilled water positioned below the plasma plume nozzle. Optical emission spectroscopy (OES) was used to diagnose the plasma system at different argon gas flow rates (1-5 L/min) and varying applied voltage values (11-15 kV). It is significant to know the processes accompanying plasma generation to measure their parameters which include the electron temperature (Te), electron number density (ne) of the plasma, Debye length (λD), and plasma frequency (fp). Our results showed an increase in the intensity of spectral lines with the increase in applied discharge voltage (11-15 kV). The maximum peak for ArI was observed at a wavelength of 811.531 nm, and the maximum peaks for nickel (Ni) were observed at wavelengths of 285.21 and 519.70 nm. Also, the results indicated a gradual increase in electron temperature (Te) and electron density (ne) values at the applied voltage of 0.403-0.468 eV. Likewise, the electron density (ne) was in the range of (11.486-13.851) × 1017 cm-3. Keywords: Atmospheric plasma jet, Nickel (Ni) plasma parameters, Electron temperature, Spectroscopic optical emission (OES).

Spatial and Temporal Dynamics in Vegetation Greenness and Its Response to Climate Change in the Tarim River Basin, China

Vegetation in ecologically sensitive regions has experienced significant alterations due to global climate change. The underlying mechanisms remain somewhat obscure owing to the spatial heterogeneity of influencing factors, particularly in the Tarim River Basin (TRB) in China. Therefore, this study targets the TRB, analyzing the spatial and temporal dynamics of vegetation greenness and its climatic determinants across multiple spatial scales. Utilizing Normalized Difference Vegetation Index (NDVI) data, vegetation greenness trends over the past 23 years were assessed, with future projections based on the Hurst exponent. Partial correlation and multiple linear regression analyses were employed to correlate NDVI with temperature (TMP), precipitation (PRE), and potential evapotranspiration (PET), elucidating NDVI’s response to climatic variations. Results revealed that from 2000 to 2022, 90.1% of the TRB exhibited an increase in NDVI, with a significant overall trend of 0.032/decade (p < 0.01). The difference in NDVI change across sub-basins and vegetation types highlighted the spatial disparity in greening. Notable greening predominantly occurred near rivers at lower elevations and in extensive cropland areas, with projections indicating continued greening in some regions. Conversely, future trends mainly suggested a shift towards browning, particularly in higher-elevation areas with minimal human influence. From 2000 to 2022, the TRB experienced a gradual increase in TMP, PRE, and PET. The latter two factors were significantly correlated with NDVI, indicating their substantial role in greening. However, vegetation sensitivity to climate change varied across sub-basins, vegetation types, and elevations, likely due to differences in plant characteristics, hydrothermal conditions, and human disturbances. Despite climate change influencing vegetation dynamics in 51.5% of the TRB, its impact accounted for only 25% of the total NDVI trend. These findings enhance the understanding of vegetation ecosystems in arid regions and provide a scientific basis for developing ecological protection strategies in the TRB.

Underwater temperature and pressure monitoring for deep-sea SCUBA divers using optical techniques

The safety of SCUBA divers remains at high risk in deep-sea owing to multiple factors such as dangerous surrounding, rely upon technical equipment necessary for life support, decreased underwater navigation, and communication infrastructure. Gradual decrease and increase in water temperature and pressure corresponding to depth are among the most common problems that cause most of the fatalities in deep-sea diving. Therefore, different gadgets for accurate measurement of vital parameters, reliable navigation, and seamless communication are of prime importance. In this paper, we propose an all-optical technique for local and remote monitoring of underwater temperature and pressure for deep-sea SCUBA divers based on fiber Bragg grating (FBG) sensors and underwater optical communication-single mode fiber (UWOC-SMF) integrated transmission system. The proposed technique is implemented using two FBG temperature and pressure sensors fixed over diver’s suit and UWOC-SMF integrated transmission system for simultaneous local and remote monitoring of underwater temperature and pressure. Remote monitoring of underwater temperature and pressure is achieved at ship station through a remotely operated underwater vehicle (ROV) and UWOC-SMF integrated transmission system by means of shifts in the original Bragg wavelengths of sensors due to temperature and pressure variations. The performance of the sensors is analyzed for pressure and temperature in the range of 0 to 6.4 MPa (≈0 to 655 mH2O) and 40 to −2°C, respectively corresponding to different depths. The results show that the proposed technique can work well in the deep ocean over a range of pressures and temperatures of 0–7 MPa and 40 to −2°C while achieving a temperature sensitivity of 4.3 p.m./°C and a pressure sensitivity of 30.5 p.m./MPa. Clear spectra of reflected signals from FBG sensors at ship station are achieved after signal transmission over UWOC-SMF hybrid link.

Annual gametogenic development of the Asiatic hard clam, Meretrix meretrix, collected from the west coast of Moheshkhali Island, Cox's Bazar, Bangladesh

AbstractWe investigated the annual gametogenic development of the Asiatic hard clam, Meretrix meretrix, collected from the west coast of Moheshkhali Island, Cox's Bazar, Bangladesh, by using biometry and histology through monthly sampling from July 2018 to June 2019. After biometric measurements, cross sections were cut for histology to determine the sex and gonadal maturity of the clams. Condition index (CI) showed two distinct peaks in July and December, which indicated that clams were ripe during these months, and a subsequent decrease in CI reflected spawning, which was consistent with histology. Our study revealed a biannual spawning cycle of the clams and gametogenesis starting in October and June. Spawning occurred from February to May and July to September. Maturity index (MI) showed two distinct peaks in July (3.50) and January (3.60) when most of the clams were in late developing or ripe stages. A gradual increase in temperature from annual minima in conjunction with decreasing salinity levels may trigger spawning in February, but spawning in July was initiated when salinity levels increased from annual minima. The data could be used by resource managers for the conservation of this commercial species and to time harvesting for the best quality clams without interrupting spawning activity.

GOLD ENRICHMENT MECHANISM IN MID-OCEAN RIDGE HYDROTHERMAL SYSTEMS: AN EXAMPLE FROM THE LONGQI HYDROTHERMAL FIELD ON THE ULTRASLOW-SPREADING SOUTHWEST INDIAN RIDGE

Abstract In mid-ocean ridge (MOR) hydrothermal systems, the gold grade of sea-floor massive sulfides (SMSs) is negatively correlated with the spreading rate of the ridge. Previous investigations have addressed the distribution of gold in sulfides from hydrothermal fields hosted by ultramafic rocks. In contrast, the gold enrichment mechanisms in sulfides from hydrothermal fields hosted by mafic rocks in ultraslow-spreading ridge environments are less well constrained. The basalt-hosted Longqi hydrothermal field, located on the classic ultraslow-spreading Southwest Indian Ridge, provides an opportunity to examine gold enrichment mechanisms in such an environment. Two ore-forming stages are identified in chimney fragments: anhydrite + barite + colloidal/porous pyrite (Py1) + marcasite + fine-grained sphalerite (stage 1); euhedral-subhedral pyrite (Py2) + coarse-grained sphalerite + chalcopyrite + isocubanite (stage 2). Py1 is usually overgrown by marcasite, which is in turn enclosed by Py2. Py2 coexists with coarse-grained sphalerite and chalcopyrite. Abundant native gold nanoparticles occur in Py1 or at the transition zone between Py1 and Py2. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis suggests that Py1 contains higher Mo, V, Sn, and Pb and lower As, Co/Ni, and Se/Tl values compared to Py2. In situ LA-multicollector (MC)-ICP-MS analyses show that Py1 has a higher mean δ34S (+7.1‰) value than Py2 (+6.6‰). Sulfur primarily derives from MORB and seawater sulfate, of which the proportion of sulfur from seawater sulfate is between 20.5 and 47.6%. Textures, mineral assemblages, and trace element contents of sulfides indicate that the degree of mixing between hydrothermal fluids and seawater decreases as the chimney grows and is accompanied by a gradual increase in temperature. Based on data compiled from 41 hydrothermal fields hosted by basalt, the large range of sulfide δ34S from slow- and ultraslow-spreading MORs may be attributed to the wide range of sulfur sources (e.g., leaching from MOR basalt, thermochemical reduction of seawater sulfate, magma degassing, and bacterial activity), fluid-basalt interaction, and redox state (CH4/CO2 ratios). Prolonged fluid-basalt interaction and the type of chimneys, such as beehive chimneys, may lead to higher gold grades in hydrothermal fields. Moreover, low H2S content may be an important contributor to gold enrichment in basalt-hosted SMS deposits in ultraslow-spreading MOR environments.

Study on the failure mechanism of high-temperature granite under two cooling modes

In the geothermal development of hot dry rock (HDR), both the drilling of the wellbore and the heat exchange of the heat reservoir involve the effects of different cold and hot conditions on the high-temperature rock mass. The testing machine for rock mechanics was used to conduct a uniaxial compression test and carry out micro testing on the treated samples; furthermore, with the help of scanning electron microscopy the fracture mechanism of granite subjected to different temperatures and cooling methods was studied. The results show: (1) With the gradual increase in temperature, the compressive strength of granite under the two cooling methods gradually decreases. (2) The failure modes of the samples under the two cooling methods are mainly shear failure of the "Y" type. The degree of damage of the sample under water cooling is significantly greater than that under natural cooling. Electron micrographs could confirm these results. (3) It can be obtained by testing the mineral composition and element changes of granite at different temperatures. When the temperature reaches 600℃, its change is more pronounced. The results of this study can provide a theoretical reference for the failure of the wellbore and the degree of fracture of the thermal reservoir rock mass during geothermal development.

Melting of W/Cu flat type component for main limiter and its impact on plasma operation in EAST experiments

A type of actively cooled W/Cu flat-type component with high heat exhaust capacity was installed as limiter during the EAST spring plasma campaign in 2022, aiming to support the long pulse operation. Unfortunately, severe melting phenomena with obvious droplets ejection of the flat-type W/Cu limiter was repeatedly monitored by CCD and IR cameras, which not only induced the failure of component but also seriously influenced plasma operation. The high temperature around midplane of W/Cu flat-type main limiter is identified to be closely connected with ICRF induced fast ions loss. Indeed, the surface temperature of W/Cu flat-type main limiter was too high to ignore. The damage of flat-type structure, however, usually started between the joint interface of W plates and CuCrZr heat sink material. Such damage would in turn lead to the gradual increase of surface temperature which eventually would cause melting of W plates. Once melting events occurred on the W/Cu flat-type main limiter, the vast majority of cases would result in plasma disruption. Moreover, the damage of main limiter would rapidly deteriorate. Hence, more attention should be paid to how to improve the fatigue lifetime of the joint interface. Such test results of flat-type W/Cu component for limiter are important references for the improvement and application of W/Cu flat-type component for high heat flux area in fusion devices.

The combination of RNA-seq transcriptomics and data-independent acquisition proteomics reveal the mechanisms and function of different gooses testicular development at different stages of laying cycle

Egg production performance is an important economic trait in the poultry industry. In previous studies, attention has often been paid to the growth and development of the ovaries, while there has been less research on the testicular tissue of male goose. Due to various factors, there are usually significant differences in the process of testicular spermatogenesis among different goose breeds. The Jilin white goose (JL) is a high-production local goose species in China, domesticated from Anser cygnoides, which has a high egg-laying performance and the egg-laying period can last from February to July. In the production of goose within Jilin Province, the female goose of Jilin White goose is considered as an important maternal parent of synthetic lines, and ganders from Hungarian white goose (HU), Wanxi white goose (WX) and Jilin white goose are the main male parents. Each year, all 3 gander species begin to exhibit breeding capacity in February and reach the peak of reproductive capacity by April, marked by high fertilization rates. With the gradual increase in temperature, the testicular tissue of Hungarian and Wanxi goose gradually diminishes in its ability to produce sperm. the testicular tissue undergoes significant shrinkage by the end of June, resulting in a near loss of sperm production capability, thereby yielding low fertilization rates. However, the Jilin White goose demonstrates the ability to maintain a stable sperm production capacity. Individuals with low sperm motility contribute to increased seed production costs and pose constraints on the industrial development of livestock and poultry varieties. In this study, transcriptomics and proteomics data from gooses testicular of 3 different goose breeds inclouding Jilin white goose, Wanxi white gooseand Hungary white goose sampled in 2 stages, peak of laying cycle (PLC) and end of laying cycle (ELC). In a comparative analysis between PLC and ELC groups (ELC vs. PLC) of 3 breeds, we identified 401,340,6651 differentially expressed genes (DEGs) and 18,225,323 differentially expressed proteins (DEPs), respectively. Differentially expressed genes and proteins were significantly enriched in Gene Ontology (GO) terms such as phosphotransferase activity, cytoskeletal protein binding, microtubule motor activity, channel activity and carbohydrate metabolic process. The KEGG enrichment analysis of the DEGs in testicular showed that most differentially expressed mRNAs participate in the KEGG pathways, including ECM-receptor interaction, MAPK signaling pathway, carbon metabolism, Cell cycle, VEGF signaling pathway, Lipoic acid metabolism and p53 signaling pathway. The differential expression of 4 selected DEGs (SPAG6, NEK2, HSPA4L, SERF1A) was verified by qRT-PCR, and the results were consistent with RNA-seq data. In conclusion, this study reveals the differences in gene expression regulation in testicular tissues of different goose species, and screening candidate genes and proteins related to spermatogenesis.

Experimental investigation of photoelectrical performance and thermal characteristics of ventilated building-integrated photovoltaic system utilizing lightweight and flexible crystalline silicon module

The existing large-scale of industrial buildings with lightweight insulated roofing structures presents a challenge for traditional glass crystalline silicon photovoltaic (PV) systems due to insufficient load-bearing capacity. Meanwhile, traditional PV rooftop applications also face challenges due to limited rooftop resources. To address these issues, this study proposes a ventilated building-integrated lightweight photovoltaic (VL-BIPV) system. The VL-BIPV system incorporates lightweight and flexible crystalline silicon modules, which increase rooftop load by about 6 kg/m2. Additionally, the system features a ventilation channel design to enhance thermal management performance. To evaluate the PV performance and thermal characteristics of the proposed system, an experimental setup was implemented to compare the performances of the VL-BIPV system with a building-attached lightweight photovoltaic (L-BAPV) system that utilizes color steel sheet base plates. The results demonstrate the exceptional performance of VL-BIPV system, with a 100.56% higher ratio of the product of short-circuit current and open-circuit voltage compared to L-BAPV. Moreover, the VL-BIPV system achieved a 1.77% increase in PV efficiency and a 2.35% enhancement in daily electricity generation. In hot weather, the adoption of VL-BIPV reduced the extreme temperature of PV cells by 9.23 °C below 85 °C, surpassing the 6.29 °C reduction achieved by L-BAPV system. Furthermore, the ventilation channel exhibited a gradual temperature increase with slower changes in the flow direction, while the base plate temperature decreased by 13.41 °C, which indicates that VL-BIPV can effectively reduce solar heat gain in the building envelope and improve the indoor thermal environment. The research findings provide important guidance for promoting and applying VL-BIPV technology in large-scale industrial buildings with low rooftop load-bearing capacity, thereby promoting the production and utilization of clean electricity in industrial parks.

How to quantify the regional effects of ocean temperature rise due to climate change: implications of Octopus maya ecophysiology on food security of the Yucatan shelf artisanal fishermen

The vital survival, maturation, and reproduction rates of Octopus maya were formulated according to the thermal preferences in each stage (juvenile and adult) and the bottom temperature of the Yucatan shelf projected from different shared socioeconomic pathways (SSPs): SSP1-5, to describe the species population growth in shallow waters. The dispersion of each individual in the population and the spread of the offshore population were incorporated with an integrodifference equation. For each SSP, the food security of the artisanal fishermen in the Western, Central, and Eastern Yucatan shelf region was analyzed based on the proposed availability, access, and utilization indices of Octopus maya as food. The analysis was complemented with an average monthly protein and income poverty indicators that this species’ shallow water fishery would have the capacity to supply by the year 2100. Although the proportion of the legally O. maya catchable population may be favored with the gradual increase in temperature in the coming years, this increase may not translate into greater food security for the artisanal fishermen who catch this species in shallow waters. Moreover, this fishery alone may not have the capacity to supply the average annual intake of 10.6 kg of protein per person recommended and maintain fishermen and their families above the income poverty line by 2100.

Zr as an Alternative Grain Refiner in the Novel AlSi5Cu2Mg Alloy

Al-Si-Cu-Mg alloys are among the most significant types of aluminum alloys, accounting for 85–90% of all castings used in the automotive sector. These alloys are used, for example, in the manufacturing of engine blocks and cylinder heads due to their excellent specific strength (ratio of strength to specific weight) and superior castability and thermal conductivity. This study investigated the effect of using Zr as an alternative grain refiner in the novel AlSi5Cu2Mg cylinder head alloy. The microstructure of this alloy could not be refined via common Al-Ti-B grain refiners due to its specifically designed chemical composition, which limits the maximum Ti content to 0.03 wt.%. The results showed that the addition of Zr via the AlZr20 master alloy led to a gradual increase in the solidus temperature and to the grain refinement of the microstructure with the addition of as little as 0.05 wt.% Zr. The addition of more Zr (0.10, 0.15, and 0.20 wt.%) led to a gradual grain refinement effect for the alloy. The presence of Zr in the AlSi5Cu2Mg alloy was reflected in the formation of Zr-rich intermetallic phases with acicular morphology. Such phases acted as potent nucleants for the α-Al grain.

THE INCOMPATIBILITY OFGLOBAL WARMING AND ECONOMIC GROWTH

Global warming signifies an undesirable geographical status of the planet and highlights the alarming trend of the extinction of the planet due to this unprecedented phenomenon. It is mostly caused by the gradual increase in world temperature, deforestation, emission of greenhouse gases, the melting of ice, glaciers and other adverse climatic conditions. This negative trend carries a portent for the future - a future that looks bleak and alarming. Extreme and harsh weather conditions have become common in India and other Asian countries. India has been the worst hit due to frequent occurrence of floods and heatwaves. This alarming trend should force us to think of better planning and optimum utilisation of resources without their ruthless violation. The miserable conditions of contemporary life can be, in retrospect traced to the beginning of industrialisation and capitalist economy. The evils that plague our lives have been mostly caused by the ruthless exploitation of natural resources.

Analysis of the energy efficiency of a system with a hybrid solar collector and thermal energy storage

The object of research is heat transfer in a hybrid thermal photovoltaic solar collector. International agreements and strategies aimed at combating climate change and reducing greenhouse gas emissions strongly call for the active implementation of renewable energy sources on a global scale. A special emphasis is placed on the development of solar energy, which has significant growth potential due to the constant improvement of technologies and cost reduction of production. With this in mind, the authors focused on the development and analysis of a computer model of an innovative hybrid system that effectively combines a solar collector for the simultaneous production of both thermal and electrical energy. The research included a detailed study of the temperature changes of the heat carrier in the hybrid photovoltaic solar collector and thermal accumulator during the period of solar irradiation. Thanks to careful monitoring, the main patterns of gradual temperature increase in both key components of the hybrid system were established. In addition, an assessment of the dynamics of changes in the instantaneous thermal power of the solar collector under the influence of various factors, such as the intensity of solar radiation, the angle of inclination of the collector, wind speed, etc., was carried out. The results of computer modeling showed the average indicator of the efficiency of the entire hybrid system, as well as its variations during a certain time of operation. In addition, the change in the instantaneous specific heat capacity and the overall efficiency of heat energy generation by the hybrid photovoltaic solar collector were analyzed. Special attention was paid to the study of the dynamics of changes in the thermal efficiency of the entire system, as well as its ability to efficiently store thermal energy in a specialized battery. The comprehensive analysis made it possible to obtain the key thermophysical parameters of the developed hybrid system with a photovoltaic solar collector. This data is extremely important, as it will allow engineers and scientists to accurately calculate the potential performance and efficiency of such a system when it is put into practical use in the future. In general, the results of the study emphasize the promising development of hybrid solar collectors as one of the leading technologies in the field of renewable energy in the context of global challenges of climate change.

Low-mass Population III Star Formation due to the HD Cooling Induced by Weak Lyman–Werner Radiation

Lyman–Werner (LW) radiation photodissociating molecular hydrogen (H2) influences the thermal and dynamical evolution of the Population III (Pop III) star-forming gas cloud. The effect of powerful LW radiation has been well investigated in the context of supermassive black hole formation in the early Universe. However, the average intensity in the early Universe is several orders of magnitude lower. For a comprehensive study, we investigate the effects of LW radiation at 18 different intensities, ranging from J LW/J 21 = 0 (no radiation) to 30 (H-cooling cloud), on the primordial star-forming gas cloud obtained from a three-dimensional cosmological simulation. The overall trend with increasing radiation intensity is a gradual increase in the gas cloud temperature, consistent with previous works. Due to the HD cooling, however, the dependence of gas cloud temperature on J LW deviates from the aforementioned increasing trend for a specific range of intensities (J LW/J 21 = 0.025–0.09). In HD-cooling clouds, the temperature remained below 200 K during 105 yr after the first formation of the high-density region, maintaining a low accretion rate. Finally, the HD-cooling clouds have only a low-mass dense core (above 108 cm−3) with about 1–16 M ⊙, inside of which a low-mass Pop III star with ≤0.8 M ⊙ (a so-called “surviving star”) could form. The upper limit of star formation efficiency Mcore/Mvir,gas significantly decreases from 10−3 to 10−5 as HD cooling becomes effective. This tendency indicates that, whereas the total gas mass in the host halo increases with the LW radiation intensity, the total Pop III stellar mass does not increase similarly.

Heavy oil atmospheric residue: HDS performance and life test using ARDS catalysts system

The objective of this study is to evaluate the catalyst by introducing atmospheric residue of heavy crude (H-AR) that secures full comprehensive characteristics and converts into a petroleum product, namely low sulfur fuel oil (LSFO). Furthermore, to estimate the catalyst’s lifespan under hydroprocessing conditions by monitoring its deactivation rate and maintaining consistent sulfur in LSFO products through gradual increases in reaction temperature. Prior to the hydrotreating test, the heavy crude oil underwent desalting, dewatering, and atmospheric distillation to obtained atmospheric residue (H-AR, i.e., 350°C+) for use as feedstock. The pilot plant employed a catalyst system comprising both hydrodemetallization (HDM) and hydrodesulfurization (HDS) catalysts, distributed across two fixed-bed reactors. The results showed the lifespan approximately 3.0 months as a function of time-on-stream (TOS). The H-AR feed, with its high sulfur, metals, asphaltenes, and micro carbon residue (MCR) content, poses several challenges including carbon deposition at start of run (SOR). The observed deactivation rate is attributing to the feedstock’s poor quality and its impact associated deposition of coke and metals (V and Ni) deposition with TOS.

Cretaceous stratigraphy of Antarctica and its global significance

Abstract The Cretaceous Period is particularly well represented by a thick sequence of clastic sedimentary rocks exposed in the Antarctic Peninsula region of western Antarctica. This was an active margin throughout the Late Mesozoic, and in total some 7 km+ of Cretaceous sedimentary rocks accumulated in a series of fore-, intra- and back-arc basins. The Fossil Bluff Group of eastern Alexander Island can be traced from the Jurassic–Cretaceous boundary into the Upper Albian and represents a broad-scale shallowing-upward sequence from deep marine to a prominent Upper Albian fluvial interval in which high-density forests developed at a palaeolatitude of 75° S. The Cretaceous sequence exposed in the James Ross Island group continues right through the Upper Cretaceous to the Cretaceous–Paleogene boundary. The Campanian–Maastrichtian succession in particular is over 2 km in total thickness and richly fossiliferous. The improved Cretaceous stratigraphy of Antarctica is an invaluable terrestrial record of climatic change at a high palaeolatitude. This includes a gradual increase in temperature to the Cretaceous Thermal Maximum, and then a decline to the Cretaceous–Paleogene boundary. There may be no simple link between these palaeotemperature changes and Cretaceous patterns of biotic radiation and extinction.