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Population increase impacts the climate,using the sensitive Arctic as an example

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Atmospheric and Oceanic Science Letters 2022年第2期15卷 71-74页

作者： ola m.Johannessen Elena V.Shalina Nansen Scientific Society BergenNorway Nansen International Environmental and Remote Sensing Centre St.PetersburgRussia Institute of Earth Sciences St.Petersburg State UniversityRussia

The global population during the last 100 years has increased from 2 to 7.7 billion,causing an increase in greenhouse gases in the *** order to see how population increase is directly related to physical variables of the climate,this Perspective article places observations and scenarios of climate change into context and puts forth a statistical modeling study on how the sensitive Arctic climate responds to the increasing *** relationships between population,Arctic sea-ice extent(SIE),and surface air temperature(SAT)are very strong,with the increasing population explaining 96%of the decreasing SIE and about 80%of the increasing SAT in the *** projection for the SIE using the population as a“proxy predictor”for a projected population of 10 billion people on the Earth in 2100,yields a SIE of 9.30 and 8.21 million km 2 for a linear and squared relationship,respectively,indicating no“tipping point”for the annual ice extent in this *** adds another dimension to climate understanding for the public at large using population as a proxy variable,instead of the more abstract CO_(2)*** also indicates that it is important to attempt to limit the ongoing increase in population,which is the main cause of the greenhouse gas emissions,in addition to reducing per capita emissions by an exponential increase in implementing renewable energy,a formidable challenge in this century.

关键词： Population Climate Sea ice Arctic

Will the summer sea ice in the Arctic reach a tipping point?

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Atmospheric and Oceanic Science Letters 2023年第3期16卷 58-62页

作者： ola m.Johannessen Elena V.Shalina Nansen Scientific Society BergenNorway Nansen International Environmental and Remote Sensing Centre St PetersburgRussia

The Arctic sea-ice cover has decreased in extent,area,and thickness over the last six *** global climate models project that the summer sea-ice extent(SIE)will decline to less than 1 million(mill.)km^(2) in this century,ranging from 2030 to the end of the century,indicating large ***,some models,using the same emission scenarios as required by the Paris Agreement to keep the global temperature below 2°C,indicate that the SIE could be about 2 ***^(2) in 2100 but with a large uncertainty of±1.5 ***^(2).Here,the authors take another approach by exploring the direct relationship between the SIE and atmospheric CO_(2) concentration for the summer-fall *** authors correlate the SIE and In(CO_(2)/CO_(2)r)during the period 1979-2022,where CO_(2)r is the reference value in *** these transient regression equations with an R2 between 0.78 and 0.87,the authors calculate the value that the CO_(2) concentration needs to reach for zero *** results are that,for July,the CO_(2) concentration needs to reach 691±16.5 ppm,for August 604±16.5 ppm,for September 563±17.5 ppm,and for October 620±21 *** values of CO_(2)for an ice-free Arctic are much higher than the targets of the Paris Agreement,which are 450 ppm in 2060 and 425 ppm in 2100,under the IPCC SSP1-2.6 *** these targets can be reached or even almost reached,the "no tipping point"hypothesis for the summer SIE may be valid.

关键词： Sea ice Arctic Climate change Tipping point

Highly insulating thermoplastic blends comprising a styrenic copolymer for direct‐current power cable insulation

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High Voltage 2022年第2期7卷 251-259页

作者： Yingwei Ouyang Amir masoud Pourrahimi IdaÖstergren marcus mellqvist JakobÅnevall Azadeh Soroudi Anja Lund Xiangdong Xu Thomas Gkourmpis Per‐ola Hagstrand Christian müller Department of Chemistry and Chemical Engineering Chalmers University of TechnologyGöteborgSweden Department of Electrical Engineering Chalmers University of TechnologyGöteborgSweden Innovation&Technology Borealis ABStenungsundSweden

The impact of the composition of blends comprising low‐density polyethylene(LDPE),isotactic polypropylene(PP)and a styrenic copolymer additive on the thermomechanical properties as well as the direct‐current(DC)electrical and thermal conductivity is *** presence of 5 weight percent(wt%)of the styrenic copolymer strongly reduces the amount of PP that is needed to enhance the storage modulus above the melting temperature of LDPE from 40 to 24 wt%.At the same time,the copolymer improves the consistency of the thermomechanical properties of the resulting ternary *** both the DC electrical and thermal conductivity strongly decrease with PP content,the addition of the styrenic copolymer appears to have little influence on either ***,PP in combination with small amounts of a styrenic copolymer not only allows to reinforce LDPE at elevated temperatures but also functions as an electrical conductivity‐reducing additive,which makes such thermoplastic ternary formulations possible candidates for the insulation of high‐voltage power cables.

关键词： property. blends copolymer

On the Dynamics of a Viscoelastic Fluid-Conveying Nanotube

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Fluid Dynamics & materials Processing 2022年第4期18卷 1137-1151页

作者： ola Adil Ibrahim Gunawan Widjaja Abdulhussien N.Alattabi Krishanveer Singh Yasser Fakri mustafa P.A.Krovopuskov mustafa m.Kadhim General Directorate of Curricula-ministry of Education-Iraq Baghdad10020Iraq Senior Lecturer Faculty of Public Health Universitas Indonesia/Faculty of Law Universitas Krisnadwipayana Jakarta11440Indonesia College of Petroleum Engineering Al-Ayen UniversityThi-Qar64005Iraq GLA University mathura-India MathuraChaumuhanUttar Pradesh281406India Department of Pharmaceutical Chemistry College of PharmacyUniversity of MosulMosul41002Iraq Lipetsk State Technical University Lipetsk398600Russia Department of Dentistry Kut University CollegeKutWasit52001Iraq

The objective of the presented study is to perform a vibration analysis and investigate the stability of a viscoelastic-fluid conveying pipe with an intermediate *** mathematical model is elaborated in the framework of the Euler-Bernoulli beam theory in combination with the Kelvin-Voight viscoelastic *** resulting differential equation of motion and the related boundary conditions and compatibility conditions in the mid-span support are solved analytically using a power series *** results show that an intermediate support located atξ_(s)=0.1 andξ_(s)=0.5 increases the critical velocity up to 35%and 50.15%,***,the non-dimensional critical velocity for an intermediate support atξ_(s)=0.1 is 4.83.

关键词： Fluid conveying carbon nanotube viscoelastic structural damping natural frequencies analytical method

Decreasing Arctic Sea Ice mirrors Increasing CO_2 on Decadal Time Scale

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Atmospheric and Oceanic Science Letters 2008年第1期1卷 51-56页

作者： ola m Johannessen mohn-Sverdrup Center for Global Ocean Studies and Operational Oceanography / Nansen Environmental and Remote Sensing Center Geophysical Institute University of Bergen

Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO 2 since the beginning of the 20th century, identifying a strengthening linkage, such that in recent decades the rate of sea-ice decrease mirrors the increase in CO 2 , with r ～ -0.95 over the last four decades, thereby indicating that 90% (r 2 ～ 0.90) of the decreasing sea-ice extent is empirically "accounted for" by the increasing CO 2 in the atmosphere. The author presents an empirical relation between annual sea-ice extent and global atmospheric CO 2 concentrations, in which sea-ice reductions are linearly, inversely proportional to the magnitude of increase of CO 2 over the last few decades. This approximates sea-ice changes during the most recent four decades, with a proportionality constant of 0.030 million km 2 per ppmv CO 2 . When applied to future emission scenarios of the Intergovernmental Panel on Climate Change (IPCC), this relationship results in substantially faster ice decreases up to 2050 than predicted by IPCC models. However, departures from this projection may arise from non-linear feedback effects and/or temporary natural variations on interannual timescales, such as the record minimum of sea-ice extent observed in September 2007.

关键词：气候学冰二氧化碳气候影响

Fusion-Based Deep Learning model for Automated Forest Fire Detection

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Computers, materials & Continua 2023年第10期77卷 1355-1371页

作者： mesfer Al Duhayyim majdy m.Eltahir ola Abdelgney Omer Ali Amani Abdulrahman Albraikan Fahd N.Al-Wesabi Anwer mustafa Hilal manar Ahmed Hamza mohammed Rizwanullah Department of Natural and Applied Sciences College of Community-AflajPrince Sattam bin Abdulaziz UniversityAl-Kharj16278Saudi Arabia Department of Computer Science College of Science&Art at MahayilKing Khalid UniversityMuhayel Aseer62529Saudi Arabia Department of Information Technology College of ComputerQassim UniversityAl-Bukairiyah52571Saudi Arabia Department of Computer Sciences College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Computer and Self Development Preparatory Year DeanshipPrince Sattam bin Abdulaziz UniversityAl-Kharj16278Saudi Arabia

Earth resource and environmental monitoring are essential areas that can be used to investigate the environmental conditions and natural resources supporting sustainable policy development,regulatory measures,and their implementation elevating the ***-scale forest fire is considered a major harmful hazard that affects climate change and life over the ***,the early identification of forest fires using automated tools is essential to avoid the spread of fire to a large ***,this paper focuses on the design of automated forest fire detection using a fusion-based deep learning(AFFD-FDL)model for environmental *** AFFDFDL technique involves the design of an entropy-based fusion model for feature *** combination of the handcrafted features using histogram of gradients(HOG)with deep features using SqueezeNet and Inception v3 ***,an optimal extreme learning machine(ELm)based classifier is used to identify the existence of fire or *** order to properly tune the parameters of the ELm model,the oppositional glowworm swarm optimization(OGSO)algorithm is employed and thereby improves the forest fire detection performance.A wide range of simulation analyses takes place on a benchmark dataset and the results are inspected under several *** experimental results highlighted the betterment of the AFFD-FDL technique over the recent state of art techniques.

关键词： Environment monitoring remote sensing forest fire detection deep learning machine learning fusion model

Skin tribology:Science friction?

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Friction 2013年第2期1卷 130-142页

作者： E.VAN DER heide X.ZENG m.A.mASEN Laboratory for Surface Technology and Tribology Faculty of Engineering TechnologyUniversity of TwenteDrienerlolaan 57522 NB EnschedeThe Netherlands TNO De Rondom 15612 AP EindhovenThe Netherlands

The application of tribological knowledge is not just restricted to optimizing mechanical and chemical engineering *** fact,effective solutions to friction and wear related questions can be found in our everyday *** important part is related to skin tribology,as the human skin is frequently one of the interacting surfaces in relative *** seem to solve these problems related to skin friction based upon a trial-and-error strategy and based upon on our sense for *** question of course rises whether or not a trained tribologist would make different choices based upon a science based strategy?In other words:Is skin friction part of the larger knowledge base that has been generated during the last decades by tribology research groups and which could be referred to as Science Friction?This paper discusses the specific nature of tribological systems that include the human skin and argues that the living nature of skin limits the use of conventional *** tribology requires in vivo,subject and anatomical location specific test *** predictive friction models can only partially be applied to predict in vivo skin *** reason for this is found in limited understanding of the contact mechanics at the asperity level of product-skin interactions.A recently developed model gives the building blocks for enhanced understanding of friction at the micro *** largely simplified power law based equations are currently available as general engineering ***,the need for friction control is illustrated by elaborating on the role of skin friction on discomfort and *** texturing and polymer brush coatings are promising directions as they provide way and means to tailor friction in sliding contacts without the need of major changes to the product.

关键词： friction bio-tribology skin soft tissue surface texture brush coatings

Greenland Ice Sheet Contribution to Future Global Sea Level Rise based on CmIP5 models

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Advances in Atmospheric Sciences 2014年第1期31卷 8-16页

作者： YAN Qing WANG Huijun ola m.JOHANNESSEN ZHANG Zhongshi Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences Nansen Environmental and Remote Sensing Center University of the Chinese Academy of Sciences Climate Change Research Center Chinese Academy of Sciences Nansen Scientific Society Bjerknes Centre for Climate Research Uni Research

Sea level rise （SLR） is one of the major socioeconomic risks associated with global warming. mass losses from the Greenland ice sheet （GrIS） will be partially responsible for future SLR, although there are large uncertainties in modeled climate and ice sheet behavior. We used the ice sheet model SICOPOLIS （Simulation COde for POLythermal Ice Sheets） driven by climate projections from 20 models in the fifth phase of the Coupled model Intercomparison Project （CmIP5） to estimate the GrlS contribution to global SLR. Based on the outputs of the 20 models, it is estimated that the GrIS will contribute 0-16 （0-27） cm to global SLR by 2100 under the Representative Concentration Pathways （RCP） 4.5 （RCP 8.5） scenarios. The projected SLR increases further to 7-22 （7-33） cm with 2~basal sliding included. In response to the results of the multimodel ensemble mean, the ice sheet model projects a global SLR of 3 cm and 7 cm （10 cm and 13 cm with 2~basal sliding） under the RCP 4.5 and RCP 8.5 scenarios, respectively. In addition, our results suggest that the uncertainty in future sea level projection caused by the large spread in climate projections could be reduced with model-evaluation and the selective use of model outputs.

关键词： sea level rise Greenland ice sheet ice sheet modeling model evaluation

Climate change in the North- past, present and future

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Episodes 2008年第1期31卷 163-167页

作者： Joern Thiede ola m. Johannessen Alfred-Wegner-Institute for Polar and marine Research in the Helmholtz-Association Am Handelshafen 12 D-27570 Bremerhaven Germany. Nansen Environmental and Remote Sensing Centre （NERSC） Geophysical Institute University of Bergen Thormoehlensgate 47 N-5006 Bergen Norway.

The Nordic countries have produced famous polar explorers and researchers who have generated climate research schools at a variety of locations. The dependence of these countries with respect to the lifelihood of their societies, of their use of lands and seas, the exploitation of marine living and non-living resources have made climate research an eminent topic, and many outstanding discoveries of long- and short-term climate change have been made for the first time in Scandinavia. These include early contributions to our understanding of the geological effects of continent-wide glaciations during the ice ages, the complex postglacial history of the Baltic Sea and the varved sediment sequences preserved from lakes with an extraordinary seasonality in their sediment input, as well as the detailed records of temperature, ice texture and impurities and greenhouse gas variations of the last Glacial and of the Holocene preserved in the ice cores from Greenland. Iceland with its volcanic sequences and intercalated sediment layers not only preserved the history of this subaerial segment of the mid-Atlantic Ridge, but also easily datable paleo-climate records. The fate of the Vikings, who settled during the medieval climate optimum on Iceland and later on Greenland and who lost their habitat on Greenland at the beginning of the Little Ice Age, illustrates vividly the climate-dependent subsistence of the indigenous and non-indigenous Scandinavian populations. modern Scandinavian climate research. institutions also include sophisticated modelling groups.

关键词：气候变化北方地区生存条件地质特征