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Solid rocket propulsion technology for de-orbiting spacecraft

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Chinese Journal of Aeronautics 2022年第3期35卷 128-154页

作者： adam OKNINSKI Center of Space Technologies Lukasiewicz Research Network-Institute of AviationWarsaw 02-256Poland

This paper presents the topic of using solid rocket propulsion for de-orbiting spacecraft,in order to fulfil space debris mitigation *** benefits and disadvantages of using such means are discussed.A dedicated system can be implemented in the satellite design phase and shall be a key subsystem of platforms inserted into ***,semi-controlled and controlled de-orbit can be completed using solid rocket *** impact on the space debris environment is *** requirements for dedicated propellants and systems are *** the majority of presently developed rocket systems worldwide require high burn rates,several applications,including de-orbiting,benefit from solid propellants with decreased regression *** allows limiting spacecraft accelerations and loads during de-orbit ***,the requirement of minimising solid particle generation is *** technology from the mercury and Gemini human spaceflight programmes,where de-orbit motors were used,is *** Soviet,American and Chinese film-return-capsule solid propellant retrorockets,enabling deorbit,are also presented.A detailed survey of current work worldwide on end-of-life disposal using solid propulsion is *** of developing dedicated systems are ***,an outlook on solid rocket motor utilisation for space debris mitigation is provided.

关键词： De-orbit De-orbiting technology End-of-life disposal Satellite propulsion system development Solid propellant Solid rocket motor Space debris mitigation Space traffic management

mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration

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Neural Regeneration Research 2025年第3期20卷 805-807页

作者： Josém.Izquierdo Centro de Biología molecular Severo Ochoa(CBm) Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... 详细信息

关键词： Latin potential lasting

Intraseasonal asynchrony as a factor boosting isolation within a metapopulation: The case of the clouded apollo

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Insect Science 2019年第5期26卷 911-922页

作者： Pawet adamski adam m.Cmiel Anna m.Lipinska Polish Academy of Sciences Institute of Nature ConservationKrakowPoland

This article discusses the influence of phenology-related intraseasonal asynchrony on metapopulation dynamics and stability. As the part played by intraseasonal asynchrony is as yet unclear and poorly described, greater account of it should be taken in both metapopulation research and conservation practice. The subpopulations of the Parnassius mnemosyne metapopulation studied here are strongly isolated because of the phenological shift between them, despite the relatively small physical distances between them. This isolation is the result of a significant temporal shift in the species' flight periods in the main metapopulation centers: in som e seasons its flight times in the different subpopulations did not overlap at all. The predicted results of such strong intraseasonal asynchrony are not altogether clear. On the one hand, they reduce the vulnerability of the entire metapopulation to the effects of short-term random disasters. On the other, the ever-greater isolation of subpopulations may cause the metapopulation to becom e a nonequilibrium one, which will have a serious impact on its long-term survival.

关键词： allee effect demography mathematical modeling metapopulation stability phenology

Proactive interburden fracturing using UIS drilling with validation monitoring

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International Journal of mining Science and Technology 2021年第1期31卷 3-7页

作者： adam Lines Anglo American Grosvenor MineMoranbah 4744Australia

A series of gas inrush events occurred during development at Grosvenor mine resulting in exposure to elevated levels of methane at the production face.A total of 22 gas inrush events occurred,with between 15 and 130 m3 of methane released during each *** presence of an undrained seam in the immediate floor,geotechnical characteristics of the floor,and the stress environment all contributed to these dynamic floor events,while the geological characteristics of the seam below,such as the seam thickness and ash content of 75%,prevented effective ***,events only occurred in headings mined parallel to the principal horizontal stress *** cut-throughs(C/T)perpendicular to the principal stress direction no events occurred,and higher methane levels were observed at the production *** solution to preventing the gas inrush events involved creating a conduit in the interburden between the mined seam and the seam in the immediate floor to allow the gas to be drained during the development of the headings,as occurred in the cut-throughs(cut-through and cross-cut are regional terms that are analogous).A series of underground inseam(UIS)holes were drilled using the directional drill rig with the aim of fracturing this interburden ahead of the face and promote floor failure to allow the gas to release *** floor fracturing was conducted using water pressure generated from a longwall salvage pump,with the current UIS drilling equipment retrofitted with a series of subs,packers and a fracturing *** packers and the fracturing tool were shifted to desired locations along the drilled UIS borehole to achieve the required *** fractures were monitored using a proving hole and with a HYDAC data logger attached to the salvage pack,with the results analysed on the surface to ensure connectivity to the working seam.

关键词： Gas drainage Floor fracking UIS drilling

Semantic linking of complex properties,monitoring processes and facilities in web-based representations of the environment

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International Journal of Digital Earth 2016年第3期9卷 300-324页

作者： adam m.Leadbetter Peter N.Vodden marine Institute Co.GalwayIreland Centre for Ecology and Hydrology Lancaster Environment CentreLancasterUK

Where a virtual representation of the Earth must contain data values observed within the physical Earth system,data models are required that allow the integration of data across the silos of various Earth and environmental sciences *** a mapping between the well-defined terminologies of these silos is a stubborn *** paper presents a generalised ontology for use within Web 3.0 services,which builds on European Commission spatial data infrastructure *** presented ontology acknowledges that there are many complexities to the description of environmental properties which can be observed within the physical Earth *** ontology is shown to be flexible and robust enough to describe concepts drawn from a range of Earth science disciplines,including ecology,geochemistry,hydrology and *** paper also demonstrates the alignment and compatibility of the ontology with existing systems and shows applications in which the ontology may be deployed.

关键词： observable properties monitoring properties environmental monitoring facilities semantic web geospatial data integration

Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 177-192页

作者： m.NAVEED m.ImRAN T.ASGHAR Z.ABBAS Department of mathematics Division of Science and TechnologyUniversity of Education Department of mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAm).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

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Brain-penetrating neurotrophic factor mimetics: HER-096 as a disease-modifying therapy for Parkinson’s disease

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Neural Regeneration Research 2025年第4期20卷 1094-1095页

作者： Natalia Kulesskaya Kira m.Holmström Henri J.Huttunen Herantis Pharma Plc EspooFinland

Neurotrophic factors as a therapeutic approach in neurodegenerative diseases:A major unmet need in the field of central nervous system diseases is disease-modifying *** for decades there have been various symptomatic treatments available to alleviate the symptoms of the disease,disease-modification,*** that stop,significantly delay,or reverse the progression of the disease,has been turned out to a difficult goal to achieve.

关键词： diseases treatment therapeutic

Arctic sea-ice extent: No record minimum in 2023 or recent years

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Atmospheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola m.Johannessen Tor I.Olaussen Nansen Scientific Society BergenNorway Nansen Environmental and Remote Sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. In general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.

关键词： Sea ice Arctic minimum ice Climate

Kinetics and mechanistic investigation of epoxide/CO2 cycloaddition by a synergistic catalytic effect of pyrrolidinopyridinium iodide and zinc halides

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Journal of Energy Chemistry 2019年第10期28卷 35-42页

作者： Abdul Rehman Valentine C. Eze m.F.m.Gunam Resul adam Harvey School of Engineering Merz CourtNewcastle UniversityNewcastle Upon Tyne NE1 7RUUK Department of Chemical and Polymer Engineering University of Engineering and Technology LahoreFaisalabad CampusPakistan

Formation of styrene carbonate (SC) by the cycloaddition of CO2 to styrene oxide (SO) catalysed by pyrrolidinopyridinium iodide (PPI) in combination with zinc halides (ZnCl2, ZnBr2 and ZnI2) was investigated. Complete conversion of the SO to SC was achieved in 3 h with 100% selectivity using 1/0.5 molar (PPI/ZnI2) catalyst ratio under mild reaction conditions i.e., 100℃ and 10 bar CO2 pressure. The synergistic effect of ZnI2 and PPI resulted in more than 7-fold increase in reaction rate than using PPI alone. The cycloaddition reaction demonstrated the first-order dependence with respect to the epoxide, CO2 and catalyst concentrations. moreover, the kinetic and thermodynamic activation parameters of SC formation were determined using the Arrhenius and Eyring equations. The positive values of △H(42.8 kJ mol^-1) and △G(102.3 kJ mol^-1) revealed endergonic and chemically controlled nature of the reaction, whereas the large negative values of △S(-159.4 J mol^-1 K^-1) indicate a highly ordered activated complex at the transition state. The activation energy for SC formation catalyzed by PPI alone was found to be 73.2 kJ mol^-1 over a temperature range of 100-140℃, which was reduced to 46.1 kJ mol^-1 when using PPI in combination with ZnI2 as a binary catalyst. Based on the kinetic study, a synergistic acid-based reaction mechanism was proposed.

关键词： Cycloaddition CO2 utilization Cyclic carbonates Homogeneous catalysis Activation energy