Modelling of Eruptive Fire Occurrence and Behaviour

Eruptive fires are one of the main causes of human losses in forest fire fighting. The sudden change in fire behaviour due to a fire eruption is extremely dangerous for fire-fighters because it is unpredictable. Very little literature is available to support either modelling or occurrence prediction for this phenomenon. In this study, an unsteady physical model of fire spread is detailed, which describes the initiation and development of eruptive fires with an induced wind sub-model. The latter phenomenon is proposed as the mainspring of fire eruptions. Induced wind is proportional to the rate of spread and the rate of spread is in a non-linear relationship with induced wind. This feedback can converge or diverge depending on the conditions. The model allows both explaining why an eruption can occur and predicting explicitly its occurrence according to meteorological conditions, topographic parameters, fuel bed properties and fire front width. The model is tested by comparing its results to a set of experiments carried out at laboratory scale and during an outdoor wildfire, the Kornati accident.

Eruptive xanthomas in a patient with severe hypertriglyceridemia:A case report

BACKGROUND Xanthomatosis,a metabolic disorder causing yellow growths(xanthomas),poses challenges in lipid metabolism.This case study introduces the first documented instance within China's Yi population,emphasizing the need to explore dietary habits and treatment strategies tailored to this specific community.CASE SUMMARY Xanthomatosis is a metabolic disorder where lipid metabolism goes awry,resulting in the development of yellowish growths called xanthomas.A male patient,47 years of age,from China's Yi population,who is obese,visited our dermatology clinic complaining of widespread,non-painful rashes that have been present for two weeks.The patient works as a chef and has a diet that frequently includes oily and greasy foods.This case represents the initial documentation of xanthomatosis within the Yi population in China,offering a theoretical foundation for understanding dietary patterns and treatment options specific to the Yi community.CONCLUSION The first report of xanthomatosis in the Yi population in China lays a theoretical foundation for understanding Yi dietary patterns and treatment.

Subaqueous volcanic eruptive facies,facies model and its reservoir significance in a continental lacustrine basin:A case from the Cretaceous in Chaganhua area of southern Songliao Basin,NE China

The conventional lithofacies and facies model of subaerial and marine pyroclastic rocks cannot reflect the characteristics of subaqueous volcanic edifice in lacustrine basins.In order to solve this problem,the lithofacies of subaqueous eruptive pyroclastic rocks is discussed and the facies model is established by taking the tuff cone of Cretaceous Huoshiling Formation in the Chaganhua area of the Changling fault depression,Songliao Basin as the research object.The results indicate that the subaqueous eruptive pyroclastic rocks in the Songliao Basin can be divided into two facies and four subfacies.The two facies are the subaqueous explosive facies and the volcanic sedimentary facies that is formed during the eruption interval.The subaqueous explosive facies can be further divided into three subfacies:gas-supported hot pyroclastic flow subfacies,water-laid density current subfacies and subaqueous fallout subfacies.The volcanic sedimentary facies consists of pyroclastic sedimentary rocks containing terrigenous clast subfacies.A typical facies model of the tuff cone that is formed by subaqueous eruptions in the Songliao Basin was established.The tuff cone is generally composed of multiple subaqueous eruption depositional units and can be divided into two facies associations:near-source facies association and far-source facies association.The complete vertical succession of one depositional unit of the near-source facies association is composed of pyroclastic sedimentary rocks containing terrigenous clast subfacies,gas-supported hot pyroclastic flow subfacies,water-laid density current subfacies and subaqueous fallout subfacies from bottom to top.The depositional unit of the far-source facies association is dominated by the subaqueous fallout subfacies and contains several thin interlayered deposits of the water-laid density current subfacies.The gas-supported hot pyroclastic flow subfacies and the pyroclastic sedimentary rocks containing terrigenous clast subfacies are favorable subaqueous eruptive facies for reservoirs in continental lacustrine basins.

Southern Hemisphere Volcanism Triggered Multi-year La Niñas during the Last Millennium

To explain the recent three-year La Niña event from 2020 to 2022,which has caused catastrophic weather events worldwide,Fasullo et al.(2023)demonstrated that the increase in biomass aerosol resulting from the 2019-20 Australian wildfire season could have triggered this multi-year La Niña.Here,we present compelling evidence from paleo-proxies,utilizing a substantial sample size of 26 volcanic eruptions in the Southern Hemisphere(SH),to support the hypothesis that ocean cooling in the SH can lead to a multi-year La Niña event.This research highlights the importance of focusing on the Southern Ocean,as current climate models struggle to accurately simulate the Pacific response driven by the Southern Ocean.

Application and prospect of the fluid cooling system of solar arrays for probing the Sun

The Solar Close Observations and Proximity Experiments(SCOPE)mission,which has been proposed by the Yunnan Observatories,Chinese Academy of Sciences,aiming to operate at a distance of 5 to 10 solar radii from the Sun,plans to complete the in situ detection of the solar eruption process and observation of the magnetic field structure response.The solar flux received by the satellite ranges from 10^(3) to 10^(6) Wm^(-2),which poses challenges for thermal management of the solar arrays.In this work,the solar array cooling system of the Parker Solar Probe is discussed,the developments of the fluid loop technique are reviewed,and a research plan for a next-generation solar array cooling system is proposed.This paper provides a valuable reference for novel thermal control systems in spacecraft for solar observation.

A Case Report on Cutaneous Larva Migrans (CLM)

Cutaneous larva migrans (CLM) is a zoonotic hookworm infection of dogs and cats commonly found in low-income countries in the tropical and subtropical regions and travellers to these regions. It is caused by invasion of the skin by the parasitic larvae of hookworms which, after entry, move under the skin causing an inflammatory reaction resulting in a single or multiple tracks. Patients commonly present with a progressive, itchy, erythematous serpiginous skin rash, affecting the feet, although it can affect any other parts of the body. The diagnosis is mainly clinical, based on history and physical examination. Treatment of this condition can effectively be achieved with either albendazole or ivermectin. We present a case of a 7-year-old boy who was diagnosed with CLM after presenting to the hospital with a history of a progressive itchy rash with tracks on the left foot. Although CLM is a self-limiting disease, it causes a lot of suffering and, therefore, it is of public concern. There is a need to increase awareness of this disease among health workers, and to implement and promote preventive measures against the disease since the cause is known.

A comparison study of a solar active-region eruptive filament and a neighboring non-eruptive filament

Solar active region （AR） 11283 is a very magnetically complex region and it has produced many eruptions. However, there exists a non-eruptive filament in the plage region just next to an eruptive one in the AR, which gives us an opportunity to perform a comparison analysis of these two filaments. The coronal magnetic field extrapolated using our CESE-MHD-NLFFF code reveals that two magnetic flux ropes （MFRs） exist in the same extrapolation box supporting these two filaments, respectively. Analysis of the magnetic field shows that the eruptive MFR contains a bald-patch separatrix surface （BPSS） co- spatial very well with a pre-eruptive EUV sigmoid, which is consistent with the BPSS model for coronal sigmoids. The magnetic dips of the non-eruptive MFRs match Hα observation of the non-eruptive filament strikingly well, which strongly supports the MFR-dip model for filaments. Compared with the non-eruptive MFR/filament （with a length of about 200 Mm）, the eruptive MFR/filament is much smaller （with a length of about 20 Mm）, but it contains most of the magnetic free energy in the extrapolation box and holds a much higher free energy density than the non-eruptive one. Both the MFRs are weakly twisted and cannot trigger kink instability. The AR eruptive MFR is unstable because its axis reaches above a critical height for torus instability, at which the overlying closed arcades can no longer confine the MFR stably. On the contrary, the quiescent MFR is very firmly held by its overlying field, as its axis apex is far below the torus-instability threshold height. Overall, this comparison investigation supports that an MFR can exist prior to eruption and the ideal MHD instability can trigger an MFR eruption.

Derivation of the Spiral Motion of an Eruptive Prominence and Its Explanation

A 2D velocity field of the eruptive prominence （EP） of 1991 March 5 is obtained from its spectral data observed at the Yunnan Observatory and the velocity distributions along the entrance slit are derived for different observing frames. Under the assumption that matter in the EP undergoes axial, radial and possible rotational motions, we construct a theoretical velocity distribution of the EP along the entrance slit, to derive, by fitting, the angular velocity of rotation ω and the other three parameters （axial velocity v0, radial velocity vr and the angle between the EP plane and the line of sight Ф）. We found： an averaged angular velocity ω of 3.0 × 10^-3 arc s^-1 and the variation of ω with the height above the solar limb. As the EP rises, the matter within it in fact moves along a spiral path around its axis. The spiral motion may be explained by the theory of plasma ‘double pole diffusion＇ （DPD） caused by a sharp density gradient between the eruptive prominence and the surrounding corona. A theoretical angular velocity ω′ is estimated based on the DPD and basically coincides with ω obtained from the optimal velocity fitting.

Influence of volatile degassing on initial flow structure and entrainment during undersea volcanic fire fountaining eruptions

Release of dissolved volatiles during submarine fire fountaining eruptions can profoundly influence the buoyancy flux at the vent. Theoretical considerations indicate that in some cases buoyant magma can be erupted prior to fragmentation (~75% vesicle volume threshold). Laboratory simulations using immiscible fluids of contrasting density indicate that the structure of the source flow at the vent depends critically on the relative magnitudes of buoyancy and momentum fluxes as reflected in the Richardson number (Ri). Analogue laboratory experiments of buoyant discharges demonstrate a variety of complex flow structures with the potential for greatly enhanced entrainment of surrounding seawater. Such conditions are likely to favor a positive feedback between phreatomagmatic explosions and volatile degassing that will contribute to explosive volcanism. The value of the Richardson number for any set of eruption parameters (magma discharge rate and volatile content) will depend on water depth as a result of the extent to which the exsolved volatile components can expand.

Predictions of Galapagos Volcanic Eruption, El Niño, Ecuadorian Earthquake, Global Volcanic Eruption and Forest Fire by Sunspot Number

The earthquake number was correlated (R2 = 0.8781) with the volcano number in the East Pacific and Central American countries. The year of volcanic eruptions in the Galapagos Hot Spot (GHS) was proportional to the year of El Ni&#241o events (R2 = 0.9939) as well as to the year of earthquake events (R2 = 0.9943) in Ecuador, Colombia, and Peru from 1977 to 2016. Therefore, there can be El Ni&#241o and earthquake events in Ecuador, Colombia and Peru if there are strong volcanic eruptions either from aboveground volcanoes or undersea seamounts in the GHS during the maximal sunspot number’s period. Global volcanic eruptions were occurred during the maximal temperature departure, the latter being reversely proportional (R2 = 0.4512) to the sunspot number from 1980 to 2019. Forest fires occurred in middle latitude countries (South Korea, California, western Russia, Australia) around 35 degree from Pacific Equator during La Ni&#241a events at the time of the minimal sunspot number. Since there were intense forest fires in South Korea, Australia and California in 2019, more are expected in 2030 due to the 11 year cyclical variation in the sunspot number. The sequence of forest fires can be schematically summarized as below. 1) La Ni&#241a event in Equator causes the low vapor pressure of water due to the low sea surface temperature (SST);2) There is the pumping of freshwater from the warm Pacific Ocean to cold Equator with simultaneous transfer of heat (warm Pacific Ocean to cold Equator) and mass (water enriched Pacific Ocean to water lean Equator);3) Strong winds from dry zone pass Mountains to cause the forest fires in the residential land with bushes and trees. 4) According to the Bernoulli’s principle, the pressure gradient between the high Mountains and the low Ocean, induces the decrease of static velocity gradient for vigorously upwards flares in the Mountains and the residential land during the forest fires, which may be why it is difficult to extinguish the forest fires until burnt up bushes and trees in the Mountains and residential land with serious damages. Most effective solution to forest fires is to change the events from La Ni&#241a to El Ni&#241o for reductions of temperature and pressure gradients by Gay-Lussac’s law. Such a transition may be induced by artificial submarine volcanic eruptions among volcanoes of Fernandina, Sierra Negra and Wolf in the GHS for Korea and California. As for Australia, artificial volcanic eruptions can be caused in huge underwater volcano chain in Tasmania. The strong damages of forest fires in South Korea, Australia and California were observed in the period of the minimal sunspot number, as were in October of 2019 to February of 2020. Simultaneous transfers of momentum (velocity), heat (temperature) and mass (freshwater) were occurred from the dry zone or the hot Deserts via the Mountains and the residential land with bushes and trees to the cold Sea or Ocean. It is expected the lowest SST during the year of the minimal sunspot number to induce the strong damages of forest fires, as was in South Korea, Australia and California during the years from 2019 to 2020. CO2 emissions in Australia showed 34.5% increase, 70% coal power and no nuclear power to induce bushfires because of increases of ozone hole area and UV radiation for the hot land in the period of La Ni&#241a. Fossil fuel operation should be cut down to decrease the ozone hole area and UV radiation for weak bushfires in Australia. A few coming years may still have bushfires in Australia although their damages may not be as terrible as was in 2020. A simple remedy can be the reduction of CO2 emissions as low as possible. It was proposed that the maximal sunspot number induced El Ni&#241o event, GHS volcanic eruption and Ecuadorian earthquakes, while the minimal sunspot number induced La Ni&#241a events in Ecuador, Colombia, Peru and intense forest fires in middle latitude countries of South Korea (forest fires), Australia (bushfires) and California (wildfires).

Hydrothermal Alteration of Basaltic Rocks at Eruptive Vents on Mount Cameroon Volcano, West Africa

The study of changes in rocks due to interaction with hydrothermal fluids at active volcanoes provides insights into wall rock alteration associated with ore deposits formed in the geological past. Therefore, the nature of mineral alteration and chemical changes experienced by wall rocks can be investigated at eruptive sites on active volcanoes and the results used to better constrain ore-forming processes. In this study, we investigated the alteration at eruptive sites at Mount Cameroon volcano. These eruptive vents lie along NE-SW-trending fissures that define the Mount Cameroon rift. The vents are surrounded by cones composed largely of pyroclastic materials and to a lesser extent lava. Fumaroles (volcanic gases) rising through the vents during and after the 1999 eruption have resulted in the alteration of the pyroclastic robble along the fissures and the inner walls of the cones. Consequently, altered basaltic materials are covered with thin films of reddish, yellowish to whitish secondary minerals. These coatings result from an interaction between the surfaces of the basaltic glass with volcanically-derived acidic fluids. Petrographic investigations and XRD analysis of the basalts have identified primary mineral phases, such as olivine, pyroxene (mainly augite) and feldspars. Alteration products revealed include ubiquitous silica as well as gypsum, magnetite, feldspar, alunite and jarosite. Jarosite occurrence indicates that SO2 is the primary volcanically-derived acid source involved in coating formation. High contents of sulfur identified in the basalts indicate that melts at Mount Cameroon can be sulfur saturated as backed by previous melt inclusion data. Whole rock geochemical analysis shows a gain in silica in the altered samples and this ties with the mass balance calculations although minor gains of Al2O3, , MgO, MnO, CaO and K2O are shown by some samples.

Variations in the Patterns of Precipitation in the Watershed of the Ambato River Associated with the Eruptive Process of the Tungurahua Volcano in Ecuador

The Tungurahua, located in the Cordillera de los Andes, is the volcano with the most eruptive activity in Ecuador nowadays. 1993 records the eruptive initial process and in August of 1999, after almost 80 years of rest, the volcano begins an explosive eruptive period. This research examines the effects of the eruptive process of the volcano in the patterns of change in precipitation in the short term in a hydrographic watershed. Their results are intended to contribute to the studies carried out to understand the weather and the factors influencing its variability at local and global level. It aims also to contribute with technical data in the debate about experimenting with artificial volcanoes to weather modification. The analysis demonstrates a process of redistribution of rainfall, with significant increases in rainfall from 42.25% on December, and significant decreases of 40.03% on September, during the presence of the eruptive process.

Diagnostic imaging:Morphological and eruptive disturbances in the permanent teeth

This paper reviewed the literature on newer threedimensional imaging techniques and their applications in diagnosis and treatment planning of various dental anomalies. Developmental anomalies can occur during any of the developmental stages and are manifested clinically after the tooth is fully formed. These dental anomalies may involve a single tooth, a group of teeth, or the entire dentition. Two-dimensional diagnosticimaging, including periapical, occlusal, panoramic, or cephalometric radiographs are essential in localization and management of morphological and eruptive disorders. However, due to their inherent limitations such as insufficient precision because of unusual projection errors and lack of information about spatial relationships, these methods are considered unreliable. Thus, the use of newer image acquisition techniques that allow comprehensive three dimensional imaging and visualization of dental abnormalities is highly recommended for making a confirmatory diagnosis. The significance of accurate endodontic, surgical and orthodontic treatment planning in dental abnormalities cannot be overstated as it pertains to critical anatomic landmarks such as proximity to adjacent teeth or the mandibular canal. The precise information on spatial relationships provided by multiplanar imaging helps the dental surgeon to establish more accurate diagnosis, management strategies and also increases the patient safety. This review highlights the use of high-end diagnostic imaging modalities in diagnosis of the various morphologic and eruptive dental abnormalities.

Eruptive Variables

In this paper, a solution of the problem about how a massive star knows that it gets rid of its excess of mass before it can become a white dwarf, a pulsar or a black hole, is proposed. Many astronomers believe that this may take place in the form of a nova and supernova outburst, as well as in the form of a continuous outflow of gas [1].

Coupling between the Cenozoic west Pacific subduction initiation and decreases of atmospheric carbon dioxides

At the beginning of the Cenozoic,the atmospheric CO_(2)concentration increased rapidly from~2000 ppmv at 60 Ma to~4600 ppmv at 51 Ma,which is 5–10 times higher than the present value,and then continuous declined from~51 to 34 Ma.The cause of this phenomenon is still not well understood.In this study,we demonstrate that the initiation of Cenozoic west Pacific plate subduction,triggered by the hard collision in the Tibetan Plateau,occurred at approximately 51 Ma,coinciding with the tipping point.The water depths of the Pacific subduction zones are mostly below the carbonate compensation depths,while those of the Neo-Tethys were much shallower before the collision and caused far more carbonate subducting.Additionally,more volcanic ashes erupted from the west Pacific subduction zones,which consume CO_(2).The average annual west Pacific volvano eruption is 1.11 km~3,which is higher than previous estimations.The amount of annual CO_(2)absorbed by chemical weathering of additional west Pacific volcanic ashes could be comparable to the silicate weathering by the global river.We propose that the initiation of the western Pacific subduction controlled the long-term reduction of atmospheric CO_(2)concentration.

Comprehensive analysis of pure-quartic soliton dynamics in a passively mode-locked fiber laser

The understanding of soliton dynamics promotes the development of ultrafast laser technology. High-energy purequartic solitons(PQSs) have gradually become a hotspot in recent years. Herein, we numerically study the influence of the gain bandwidth, saturation power, small-signal gain, and output coupler on PQS dynamics in passively mode-locked fiber lasers. The results show that the above four parameters can affect PQS dynamics. Pulsating PQSs occur as we alter the other three parameters when the gain bandwidth is 50 nm. Meanwhile, PQSs evolve from pulsating to erupting and then to splitting as the other three parameters are altered when the gain bandwidth is 10 nm, which can be attributed to the existence of the spectral filtering effect and intra-cavity fourth-order dispersion. These findings provide new insights into PQS dynamics in passively mode-locked fiber lasers.

Geochronology,Eruption Sequence and Geochemistry of Mid-Late Jurassic Volcanics South of Manzhouli:Petrogenesis and Implications for Mesozoic Tectonic Regime Transformation

To the south of Manzhouli,Hulunbuir,Inner Mongolia,experienced a tectonic regime transformation from compression to extension in the mid-Mesozoic.Based on systematic research of the volcanics,petrology,volcanic facies,chronology and geochemistry of rocks in the Buridun area,two stages of volcanics are identified.The first stage named the trachyte series was formed in the late Middle Jurassic(167-163 Ma),its eruption rhythm is pyroxene trachyandesite-trachyandesite-trachyte,and its origin rock is basic volcanics from thickened lower crust,with a tectonic setting in the collision orogeny after the closure of the Mongolia Okhotsk Ocean(MOO).The second stage is a bimodal volcanic rock,formed in the early Late Jurassic(163-160 Ma).The eruption rhythm of basic volcanics in this stage is basaltic andesite-basalt-olivine basalt,which comes from the metasomatized lithospheric mantle,the acidic volcanics of which being characterized by the eruption rhythm of sedimentary-explosive-overflow facies,which came from the partial melting of newly formed lower crust,and this shows the characteristics of A-type granite;the tectonic setting is extension of the lithosphere after collision and closure of the MOO.The changes in the formation age and tectonic setting of the two stages of volcanics demonstrate that the transition time from the compressive system to the extensional system south of Manzhouli is about 163 Ma.

Nepheloid layer generation by gas eruption:unexpected experimental results

Knowledge of nepheloid layers is important to improve the understanding of physical,geological,and sedimentary processes from continental shelf to abyssal environments.We had not tried to study the nepheloid layers in a hydrate-associated tank until unexpected results occurred.Tank experimental results show that gas eruptions triggered intermediate nepheloid layers.Thus,we proposed a new mechanism of intermediate nepheloid layer generation by eruptions.The intermediate nepheloid layers were generated in uniform-density fluid,which indicated that stratified fluid is not a necessary condition for intermediate nepheloid layers.Sufficient space for advection and an oblique slope for detachment are the key ingredients for intermediate nepheloid layer generation by eruptions.Our experiments also offer a new experimental evidence for bottom nepheloid layer generation by earthquakes.Given the scale effects of laboratory experiment,it is important to determine whether submarine volcanic eruption or hydrate-associated venting causes intermediate nepheloid layer in the nature.

全球海啸相关研究进展综述

With the advancement of the global economy,the coastal region has become heavily developed and densely populated and suffers significant damage potential considering various natural disasters,including tsunamis,as indicated by several catastrophic tsunami disasters in the 21st century.This study reviews the up-to-date tsunami research from two different viewpoints:tsunamis caused by different generation mechanisms and tsunami research applying different research approaches.For the first issue,earthquake-induced,landslide-induced,volcano eruption-induced,and meteorological tsunamis are individually reviewed,and the characteristics of each tsunami research are specified.Regarding the second issue,tsunami research using post-tsunami field surveys,numerical simulations,and laboratory experiments are discussed individually.Research outcomes from each approach are then summarized.With the extending and deepening of the understanding of tsunamis and their inherent physical insights,highly effective and precise tsunami early warning systems and countermeasures are expected for the relevant disaster protection and mitigation efforts in the coastal region.

Pityriasis Rosea-Like Eruption by Covid-19 Infection: A New Case Report

Background: Coronavirus disease (Covid-19) becomes a pandemic worldwide in 2020. Different dermatological manifestations associated with Covid-19 infection like maculopapular, morbilliform, urticarial, vesicular, chilblain-like, petechiae, purpura, and livedoid rashes. Pityriasis rosea (PR) and PR-like eruptions were recently reported to increase in coronavirus cases. Aim: To evaluate and review the literature on PR and PR-like eruption associated with Covid-19 disease. Case Report: A 24-year-old female patient presented with a history of asymptomatic PR-like eruption that started during infection with the Covid-19 virus and resolved spontaneously over 14 weeks without therapy. Conclusion: PR and PR-like eruptions are not uncommon with Covid-19 disease and could be the early manifestation of SARS-CoV-2 virus infection.