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Predicting grain size-dependent superplastic properties in friction stir processed ZK30 magnesium alloy with machine learning methods

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Journal of Magnesium and Alloys 2024年第5期12卷 1931-1943页

作者： Farid Bahari-Sambran Fernando carreno c.M.cepeda-Jiménez Alberto Orozco-caballero Physical Metallurgy Department CENIM-CSICAv.Gregorio del Amo 828040 MadridSpain Department of Mechanical Engineering Chemistry and Industrial DesignPolytechnic University of MadridRonda de Valencia 328012MadridSpain

The aim of this work is to predict,for the first time,the high temperature flow stress dependency with the grain size and the underlaid deformation mechanism using two machine learning models,random forest(RF)and artificial neural network(ANN).With that purpose,a ZK30 magnesium alloy was friction stir processed(FSP)using three different severe conditions to obtain fine grain microstructures(with average grain sizes between 2 and 3μm)prone to extensive superplastic *** three friction stir processed samples clearly deformed by grain boundary sliding(GBS)deformation mechanism at high *** maximum elongations to failure,well over 400% at high strain rate of 10^(-2)s^(-1),were reached at 400℃ in the material with coarsest grain size of 2.8μm,and at 300℃ for the finest grain size of 2μ***,the superplastic response decreased at 350℃ and 400℃ due to thermal instabilities and grain coarsening,which makes it difficult to assess the operative deformation mechanism at such *** work highlights that the machine learning models considered,especially the ANN model with higher accuracy in predicting flow stress values,allow determining adequately the superplastic creep behavior including other possible grain size scenarios.

关键词： Machine learning Artificial intelligence Magnesium alloys Superplasticity Friction stir processing Grain coarsening

How can Practitioners Support citizen Volunteers in Disaster Risk Reduction? Insight from “Good and Ready” in Aotearoa New Zealand

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International Journal of Disaster Risk Science 2024年第03期15卷 374-387页

作者： Lo?c Le Dé Steve Ronoh Ei Mon Thinn Kyu Brigitte Rive School of Public Health and Interdisciplinary Studies Auckland University of Technology Pacific Health Research centre Auckland University of Technology New Zealand Red cross

Global and national policy frameworks emphasize the importance of people's participation and volunteers' role in disaster risk reduction. While research has extensively focused on volunteers in disaster response and recovery, less attention has been paid on how organizations involved in disaster risk management can support volunteers in leading and coordinating communitybased disaster risk reduction. In 2019, the New Zealand Red cross piloted the Good and Ready initiative in Auckland,Aotearoa New Zealand, with the objective to empower local people in resilience building with a focus on volunteers and community participation. This research examined the positive and negative outcomes of Good and Ready and investigated volunteers' experiences in the disaster resilience initiative. It involved the codesign of a questionnaire-based survey using participatory methods with Good and Ready volunteers, the dissemination of the survey to gather volunteers' viewpoints, and a focus group discussion with participatory activities with Red cross volunteers. The findings highlight that a key challenge lies in finding a balance between a program that provides flexibility to address contextual issues and fosters communities' ownership, versus a prescriptive and standardized approach that leaves little room for creativity and self-initiative. It pinpoints that supporting volunteers with technical training is critical but that soft skills training such as coordinating, communicating,or facilitating activities at the local level are needed. It concludes that the sustainability of Good and Ready requires understanding and meeting volunteers' motivations and expectations and that enhancing partnerships with local emergency management agencies would strengthen the program.

关键词： community-based approach Disaster risk reduction New Zealand Participation Volunteers

A survey of geothermal power generation combined with renewable energy for low carbon emissions

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cLEAN ENERGY 2024年第3期8卷 138-146页

作者： Liu, Xuyang cai, Dongsheng Ukwuoma, chiagoziem c. Huang, Qi Bamisile, Olusola chengdu Univ Technol Coll Nucl Technol & Automat Engn Chengdu Sichuan Peoples R China Southwest Univ Sci & Technol Elect Engn Dept Maiyang Sichuan Peoples R China

At present, industrial development is heavily dependent on traditional fossil energy, which has had an increasingly serious impact on the environment. clean and renewable energy has received extensive attention and its proportion in daily life has gradually increased. As a clean and renewable energy source that is not affected by changes in weather and seasons, geothermal energy has developed rapidly in recent years and has received increasing attention. According to reports, the total installed capacity of geothermal power generation in the world in 2020 was 15 950 MW-an increase of similar to 27% over 2015. At the end of 2019, the total installed capacity for global geothermal direct use was 107 727 MW-an increase of 52.0% compared with 2015; the total annual energy use was 1 020 887 TJ (283 580 GWh)-an increase of 72.3% over 2015. Through the investigation of geothermal power generation technology in recent years, the characteristics and shortcomings of various power generation methods are analysed. At the same time, this review analyzes the characteristics of geothermal energy and other renewable-energy (solar energy, water energy) coupling power generation, and analyzes the principles and characteristics of geothermal energy and various new-energy coupling power generation methods. Through investigation and analysis, this review provides a complete understanding of various geothermal power generation technologies and provides insights into the future development direction. [GRAPHIcS] .

关键词： geothermal power generation solar energy water energy combined power generation ABANDONED OIL cOMBINED SYSTEM GAS-WELLS HEAT RESOURcES DRIVEN

Investigations of nuclear chirality at iThemba LABS

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Frontiers of physics 2024年第2期19卷 7-38页

作者： R.A.Bark E.A.Lawrie c.Liu S.Y.Wang iThemba Laboratory for Accelerator Based Sciences National Research FoundationP.O.Box 722Somerset-West 7129South Africa Department of Physics University of the Western CapePrivate Bag X177535BellvilleSouth Africa Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209China

Progress in the studies of chirality in atomic nuclei at iThemba LABS is *** regions of chirality,around mass 80 and 190 have been discovered using the AFRODITE array,specifically in the nuclei^(74)As,^(78,80,82)Br,^(81)Kr,and^(193,194,198)*** phenomena have been observed,including multiple chiral bands in the same nucleus,the coexistence of octupole correlations and nuclear chirality,and the coexistence of pseudo spin and nuclear *** best example of chiral degeneracy to date was found in ^(194)*** level scheme of ^(106)Ag has been revisited and interpreted in terms of two-and four-quasiparticle *** using the particle-rotor model have shown that the fingerprints of chirality in the two-quasiparticle system only can occur in an idealised model *** systems with a higher number of quasiparticles,the calculations showed that nuclear chirality can persist.

关键词： chirality high-spin states particle-rotor model

Effects of dust controls on respirable coal mine dust composition and particle sizes:case studies on auxiliary scrubbers and canopy air curtain

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International Journal of coal Science & Technology 2024年第3期11卷 86-101页

作者： F.Animah c.Keles W.R.Reed E.Sarver Department of Mining and Minerals Engineering Virginia Polytechnic Institute&State UniversityBlacksburgVAUSA National Institute of Occupational Safety and Health(NIOSH) PittsburghPAUSA

control of dust in underground coal mines is critical for mitigating both safety and health *** decades,the National Institute of Occupational Safety and Health(NIOSH)has led research to evaluate the effectiveness of various dust control technologies in coal *** studies have included the evaluation of auxiliary scrubbers to reduce respirable dust downstream of active mining and the use of canopy air curtains(cAcs)to reduce respirable dust in key operator *** detailed dust characterization was not a focus of such studies,this is a growing area of *** preserved filter samples from three previous NIOSH studies,the current work aims to explore the effect of two different scrubbers(one wet and one dry)and a roof bolter cAc on respirable dust composition and particle size *** this,the preserved filter samples were analyzed by thermogravimetric analysis and/or scanning electron microscopy with energy dispersive *** indicate that dust composition was not appreciably affected by either scrubber or the ***,the wet scrubber and cAc appeared to decrease the overall particle size *** an effect of the dry scrubber was not consistently observed,but this is probably related to the particular sampling location downstream of the scrubber which allowed for significant mixing of the scrubber exhaust and other return *** from the insights gained with respect to the three specific dust control case studies revisited here,this work demonstrates the value of preserved dust samples for follow-up investigation more broadly.

关键词： Respirable dust Dust control SEM–EDX Scrubber canopy air curtain Silica

n-Alkane bound biomarker fingerprints from asphaltenes in the bitumens of Eastern Dahomey Basin,Nigeria:Source and genetic implications

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Petroleum Research 2024年第1期9卷 85-91页

作者： Modupe A.Egbeola Olubunmi c.Adeigbe Olajide J.Adamolekun Department of Geology University of IbadanIbadanNigeria Structural Geology and Tectonics Institute of Applied GeosciencesKIT-Karlsruhe Institute of TechnologyAdenauerring 20a76131KarlsruheGermany

The asphaltene fractions of the bitumens of Eastern Dahomey Basin in Nigeria,were analyzed by flash pyrolysis-gas chromatography(Py-Gc)method in order to unravel its geochemical history and *** distributions of the initial biomarkers of the original oils from the pyrolysates are related to the assessment of organic matter source,paleo-redox conditions and source environment during ***,it effectively establishes the genetic relationship of the *** n-alkane distributions in the pyrolysates reveal nc_(9)-nc_(32)n-alkanes,maximizing at nc_(14),isoprenoids-pristane(Pr)and phytane(Ph),and some n-alkene *** peaks of low to medium-weight nc_(9)-nc20 n-alkanes and low peaks of nc_(21)+n-alkanes characterize the *** reveal that abundant algal organic matter with some terrigenous inputs contributed to the source rock of the *** high concentration of marine organic matter inputs to the source rock is further confirmed by the nc_(17)/nc27 ratios which range from 5.39 to 19.82 and shows the predominance of nc_(17)*** general unimodal n-alkane distributions in the bitumens indicate derivation from similar organic matter types showing that they are genetically *** anoxic to suboxic environmental conditions that prevailed during the deposition of the sediments is revealed by the isoprenoids,Pr/Ph ratios(0.72-1.28).Pristane/nc_(17)and Phytane/nc_(18)range from 0.16 to 0.33 and 0.22 to 0.56,revealing that the bitumens were from predominantly marine organic matter(type II kerogen)preserved in a reducing environment with no evidence of ***,the Ph/nc_(18)ratio and the cross plot of Pr+Ph/nc_(17)+nc_(18)allow the classification of the bitumens into two subfamilies/groups(A and B).The bitumen samples have low wax content as indicated by the degree of waxiness ranging from 0.21 to 0.38 which confirms low terrigenous *** on the carbon preference index(cPI:0.92 to 1.55)and odd-even predo

关键词： Genetic relationship Flash pyrolysis Biomarker Asphaltene Pyrolysates

Targeted nanopore sequencing for the identification of novel PRMT1 circRNAs unveils a diverse transcriptional profile of this gene in breast cancer cells

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Genes & Diseases 2024年第2期11卷 589-592页

作者： Maria Papatsirou Andreas Scorilas Diamantis c.Sideris christos K.Kontos Department of Biochemistry and Molecular Biology National and Kapodistrian University of AthensPanepistimiopolisAthens GR 15701Greece

Long-read sequencing with nanopore technology has been widely utilized for the identification of the full-length sequence of RNA molecules."It is especially suitable for the identification of circular RNAs(circRNAs),which are regulatory molecules that are regarded as promising non-invasive biomarkers for various human malignancies,including breast cancer.2 The impact of circRNAs derived from the protein arginine methyltransferase 1(PRMT1)gene has not been clarified yet,even though the effect of PRMT1-mediated methylation on breast cancer cell characteristics has been well established.

关键词： PRMT1 breast cancer

Hydrocarbon indication in Rio Bonito Formation sandstone:Implication for cO_(2)storage in São Paulo,Brazil

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Energy Geoscience 2024年第1期5卷 331-341页

作者： Richardson M.Abraham-A Haline V.Rocha Saulo B.de Oliveira colombo c.G.Tassinarri Orlando c.da Silva Institute of Energy and Environment University of São PauloSão PauloBrazil Research centre for Greenhouse Gas Innovation University of São PauloSão PauloBrazil

São Paulo State has witnessed cO_(2)storage-based investigations considering the availability of suitable geologic structures and proximity to primary cO_(2)source sinks related to bioenergy and carbon capture and storage(BEccS)*** current study presents the hydrocarbon viability evaluations and cO_(2)storage prospects,focusing on the sandstone units of the Rio Bonito *** objective is to apply petrophysical evaluations with geochemical inputs in predicting future hydrocarbon(gas)production to boost cO_(2)storage within the study *** study used data from eleven wells with associated wireline logs(gamma ray,resistivity,density,neutron,and sonic)to predict potential hydrocarbon accumulation and fluid mobility in the investigated *** samples(shale and carbonate)obtained from depths>200 m within the study location have shown bitumen *** geochemistry data of the Rio Bonito Formation shale beds suggest they are potential hydrocarbon source rocks and could have contributed to the gas accumulations within the sandstone *** drilled well data,e.g.,cB-1-SP and TI-1-SP,show hydrocarbon(gas)presence based on the typical resistivity and the combined neutron-density responses at depths up to 3400 m,indicating the possibility of other hydrocarbon members apart from the heavy oil(bitumen)observed from the near-surface rocks *** the three-dimensional(3-D)model,the free fluid indicator(FFI)is more significant towards the southwest and southeast of the area with deeper depths of occurrence,indicating portions with reasonable hydrocarbon recovery rates and good prospects for cO_(2)injection,circulation and permanent ***,future studies based on contemporary datasets are required to establish the hydrocarbon viability further,foster gas production events,and enhance cO_(2)storage possibilities within the region.

关键词： ParanáBasin Hydrocarbon indication Sandstone reservoirs Rio Bonito Formation cO_(2)storage Hydrocarbon recovery factor Fluid injection rate

Isolation of the mucilages from Hibiscus rosasinensis *** Okra(Abelmoschus esculentus linn.) and studies of the binding effects of the mucilages

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Asian Pacific Journal of Tropical Medicine 2010年第7期3卷 539-543页

作者： Ameena K dilip.c Saraswathi R Krishnan PN Sankar c Simi SP Al Shifa college of Pharmacy KizhatturPerinthalmanna.Kerala679325India

Objective:To isolate and evaluate comparatively the binding efficacy of the mucilages obtained from the plants of Hibiscus rosasinensis and Okra(Abelmoschus esculentus).Methods:Extraction of mucilages from the leaves of Hibiscus and pods of Okra(Ladies finger) was carried out by a cold maceration *** extracted mucilages were subjected to various physicochemical properties for its suitability as an excipient in the formulation of tablet dosage *** concentrations(10,8,5,2 and 1%w/v) of binder solutions of Hibiscus and Okra were used for the formulation of tablets and the formulated tablets were evaluated by studying the standard parameters like diameter,thickness,weight variation,hardness,friability,disintegration and in vitro *** studies of the formulated tablets were conducted for four weeks. Results:The formulated tablets prepared using the mucilages of both Hibiscus and Okra had good *** in vitro drug release profile of the tablets prepared using Okra mucilage had an optimum of 90%at a mucilage concentration of 1%w/v concentration mucilage itself within 4 ***:According to the observations,the lower concentration levels of Okra can be used as an alternative binder to *** higher concentration levels of Okra mucilage show a slow and sustained release,and can be considered as an alternative natural excipient in the modified drug delivery *** the same time,the above natural excipient of Hibiscus mucilage could be used as a platform for prolonged release if its binder concentrations are increased.

关键词： Formulation Hibiscus Tablets