| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
- Mishra, A, et al.
(författare)
-
Diminishing benefits of urban living for children and adolescents' growth and development
- 2023
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 615:7954, s. 874-883
-
Tidskriftsartikel (refereegranskat)abstract
- Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
|
|
| 19. |
|
|
| 20. |
-
- 2018
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
-
Forskningsöversikt (refereegranskat)
|
|
| 21. |
- Abel, I, et al.
(författare)
-
Overview of the JET results with the ITER-like wall
- 2013
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10, s. 104002-
-
Tidskriftsartikel (refereegranskat)abstract
- Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Z(eff) (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H-98,H-y2 close to 1 and beta(N) similar to 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential.
|
|
| 22. |
- Abreu, P., et al.
(författare)
-
Measurement of the gluon fragmentation function and a comparison of the scaling violation in gluon and quark jets
- 2000
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 13:4, s. 573-589
-
Tidskriftsartikel (refereegranskat)abstract
- The fragmentation functions of quarks and gluons are measured in various three-jet topologies in Z decays from the full data set collected with the DELPHI detector at the Z resonance between 1992 and 995. The results at different values of transverse momentum-like scales are compared. A parameterization of the quark and gluon fragmentation functions at a fixed reference scale is given. The quark and gluon fragmentation functions show the predicted pattern of scaling violations. The scaling violation for quark jets as a function of a transverse momentum-like scale is in a good agreement with that observed in lower energy e+e- annihilation experiments. For gluon jets it appears to be significantly stronger. The scale dependences of the gluon and quark fragmentation functions agree with the prediction of the DGLAP evolution equations from which the colour factor ratio CA/CF is measured to be: CA/CF = 2.26 ± 0.09stat. ± 0.06sys. ± 0.12clus.,scale..
|
|
| 23. |
- Abreu, P., et al.
(författare)
-
Search for sleptons in e+e- collisions at √s = 183 to 189 GeV
- 2001
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 19:1, s. 29-42
-
Tidskriftsartikel (refereegranskat)abstract
- Data taken by the DELPHI experiment at centre-of-mass energies of 183 GeV and 189 GeV with a total integrated luminosity of 212 pb-1 have been used to search for the supersymmetric partners of the electrons, muons, and taus in the context of the Minimal Supersymmetric Standard Model (MSSM). The decay topologies searched for were the direct decay (ℓ̃ → ℓx̃), producing acoplanar lepton pairs plus missing energy, and the cascade decay (ℓ → ℓx̃0 2 → ℓγx̃0 1), producing acoplanar lepton and photon pairs plus missing energy. The observed number of events is in agreement with Standard Model predictions. The 95% CL excluded mass limits for selectrons, smuons and staus are mẽ ≤ 87 GeV/c2, mμ̃ ≤ 80 GeV/c2 and mτ̃ 75 GeV/c2, respectively, for values of μ=-200 GeV/c2 and tanβ=1.5.
|
|
| 24. |
- Abreu, P., et al.
(författare)
-
Study of dimuon production in photon-photon collisions and measurement of QED photon structure functions at LEP
- 2001
-
Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 19:1, s. 15-28
-
Tidskriftsartikel (refereegranskat)abstract
- Muon pair production in the process e+e- → e+e- μ+μ- is studied using the data taken at LEP1 (√s ≃ mz) with the DELPHI detector during the years 1992-1995. The corresponding integrated luminosity is 138.5 pb-1. The QED predictions have been tested over the whole Q2 range accessible at LEP1 (from several GeV2/c4 to several hundred GeV2/c4) by comparing experimental distributions with distributions resulting from Monte Carlo simulations using various generators. Selected events are used to extract the leptonic photon structure function Fγ 2. Azimuthal correlations are used to obtain information on additional structure functions, Fγ A and Fγ B, which originate from interference terms of the scattering amplitudes. The measured ratios Fγ A/Fγ 2 and FγB/Fγ 2 are significantly different from zero and consistent with QED predictions.
|
|
| 25. |
- Akiba, K., et al.
(författare)
-
LHC forward physics
- 2016
-
Ingår i: Journal of Physics G: Nuclear and Particle Physics. - : IOP Publishing. - 0954-3899 .- 1361-6471. ; 43:11
-
Tidskriftsartikel (refereegranskat)
|
|
| 26. |
- Bécoulet, A., et al.
(författare)
-
Science and technology research and development in support to ITER and the Broader Approach at CEA
- 2013
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10
-
Tidskriftsartikel (refereegranskat)abstract
- In parallel to the direct contribution to the procurement phase of ITER and Broader Approach, CEA has initiated research & development programmes, accompanied by experiments together with a significant modelling effort, aimed at ensuring robust operation, plasma performance, as well as mitigating the risks of the procurement phase. This overview reports the latest progress in both fusion science and technology including many areas, namely the mitigation of superconducting magnet quenches, disruption-generated runaway electrons, edge-localized modes (ELMs), the development of imaging surveillance, and heating and current drive systems for steady-state operation. The WEST (W Environment for Steady-state Tokamaks) project, turning Tore Supra into an actively cooled W-divertor platform open to the ITER partners and industries, is presented.
|
|
| 27. |
- Bombarda, F., et al.
(författare)
-
Runaway electron beam control
- 2019
-
Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
-
Tidskriftsartikel (refereegranskat)
|
|
| 28. |
- Chiquito, Eric
(författare)
-
Digitalized contract definition and negotiations for the agreement of rights and obligations in electronic auctions
- 2022
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Negotiations of different kinds are used to trade goods and services. Within these, the creation of a signed agreement or contract that is binding for the agreeing parties helps also the gathering of evidence that can be used in case of disputes and for adjudication. Traditionally, contracts are established on paper agreements that are signed by all the involved parties and by a law enforcement entity that ensure its legality in a court of law. These contracts have evolved with the introduction of Information Technology (IT) where the negotiation of goods and services is mainly virtual and/or automatized. The consistency and processing time of the computers allow for negotiations to be more efficient than ever. Digitalized negotiations allow for auctioning systems providing a mechanism to efficiently match demand and supply in the exchange of goods and services. Such suctioning systems allow multiple users to iteratively or non-iteratively compete against one another to achieve allocative efficiency. Lately, digitalized auctions are implemented using Blockchain systems with the use of Smart Contracts to archieve decentralization. These are implemented as a digital script that may encode any set of rules written as code, with the validity of the code being enforced by the Blockchain's consensus mechanism. These Smart Contracts computations however tend to be expensive when executed and limited by the blocksize. This thesis studies the creation of digitized negotiation protocols and contract definition following the needs of traditional trading and auctioning systems. We investigate the use of Ricardian Contracts for flexible representation of rights and obligations of entities in the context of circular economy in both single and multi-attribute auctions. We analyze the implication of digitized agreements in the context of data sharing. Furthermore, we analyze how usage control policies can be represented into Ricardian Contracts in the context of intellectual property protection, compliance with regulations, and digital rights management.Finally, we analyze the properties that a system that supports the mentioned models should have and how to implement it in the context of distributed auctioning systems by contrasting available state-of-the-art. The main contributions of the thesis are: (1) The creation of a multi-attribute auctioning protocol for the circular economy which implements Ricardian Contracts for the representation of rights and obligations. (2) A method to negotiate obligations and access provisions with multi-level Ricardian contracts, and automatically enforce those provisions with access control. (3) A state-of-art analysis on distributed and decentralized auctioning systems where the key properties of auctioning systems are identified and are evaluated against the current implementations.
|
|
| 29. |
- Crous, P. W., et al.
(författare)
-
Fungal Planet description sheets : 951-1041
- 2019
-
Ingår i: Persoonia. - : RIJKSHERBARIUM. - 0031-5850 .- 1878-9080. ; 43, s. 223-425
-
Tidskriftsartikel (refereegranskat)abstract
- Novel species of fungi described in this study include those from various countries as follows: Antarctica,Apenidiella antarctica from permafrost, Cladosporium fildesense from an unidentified marine sponge. Argentina,Geastrum wrightii on humus in mixed forest. Australia, Golovinomyces glandulariae on Glandularia aristigera,Neoanungitea eucalyptorum on leaves of Eucalyptus grandis, Teratosphaeria corymbiicola on leaves of Corymbiaficifolia, Xylaria eucalypti on leaves of Eucalyptus radiata. Brazil, Bovista psammophila on soil, Fusarium awaxy onrotten stalks of Zea mays, Geastrum lanuginosum on leaf litter covered soil, Hermetothecium mikaniae-micranthae(incl. Hermetothecium gen. nov.) on Mikania micrantha, Penicillium reconvexovelosoi in soil, Stagonosporopsis vannacciifrom pod of Glycine max. British Virgin Isles, Lactifluus guanensis on soil. Canada, Sorocybe oblongisporaon resin of Picea rubens. Chile, Colletotrichum roseum on leaves of Lapageria rosea. China, Setophoma cavernafrom carbonatite in Karst cave. Colombia, Lareunionomyces eucalypticola on leaves of Eucalyptus grandis. CostaRica, Psathyrella pivae on wood. Cyprus, Clavulina iris on calcareous substrate. France, Chromosera ambiguaand Clavulina iris var. occidentalis on soil. French West Indies, Helminthosphaeria hispidissima on dead wood.Guatemala, Talaromyces guatemalensis in soil. Malaysia, Neotracylla pini (incl. Tracyllales ord. nov. and Neotracyllagen. nov.) and Vermiculariopsiella pini on needles of Pinus tecunumanii. New Zealand, Neoconiothyriumviticola on stems of Vitis vinifera, Parafenestella pittospori on Pittosporum tenuifolium, Pilidium novae-zelandiaeon Phoenix sp. Pakistan, Russula quercus-floribundae on forest floor. Portugal, Trichoderma aestuarinum fromsaline water. Russia, Pluteus liliputianus on fallen branch of deciduous tree, Pluteus spurius on decaying deciduous wood or soil. South Africa, Alloconiothyrium encephalarti, Phyllosticta encephalarticola and Neothyrostromaencephalarti (incl. Neothyrostroma gen. nov.) on leaves of Encephalartos sp., Chalara eucalypticola on leaf spots ofEucalyptus grandis x urophylla, Clypeosphaeria oleae on leaves of Olea capensis, Cylindrocladiella postalofficiumon leaf litter of Sideroxylon inerme, Cylindromonium eugeniicola (incl. Cylindromonium gen. nov.) on leaf litter ofEugenia capensis, Cyphellophora goniomatis on leaves of Gonioma kamassi, Nothodactylaria nephrolepidis (incl.Nothodactylaria gen. nov. and Nothodactylariaceae fam. nov.) on leaves of Nephrolepis exaltata, Falcocladiumeucalypti and Gyrothrix eucalypti on leaves of Eucalyptus sp., Gyrothrix oleae on leaves of Olea capensis subsp.macrocarpa, Harzia metro-sideri on leaf litter of Metrosideros sp., Hippopotamyces phragmitis (incl. Hippopotamycesgen. nov.) on leaves of Phragmites australis, Lectera philenopterae on Philenoptera violacea, Leptosilliamayteni on leaves of Maytenus heterophylla, Lithohypha aloicola and Neoplatysporoides aloes on leaves of Aloesp., Millesimomyces rhoicissi (incl. Millesimomyces gen. nov.) on leaves of Rhoicissus digitata, Neodevriesiastrelitziicola on leaf litter of Strelitzia nicolai, Neokirramyces syzygii (incl. Neokirramyces gen. nov.) on leaf spots of Syzygium sp., Nothoramichloridium perseae (incl. Nothoramichloridium gen. nov. and Anungitiomycetaceae fam.nov.) on leaves of Persea americana, Paramycosphaerella watsoniae on leaf spots of Watsonia sp., Penicilliumcuddlyae from dog food, Podocarpomyces knysnanus (incl. Podocarpomyces gen. nov.) on leaves of Podocarpusfalcatus, Pseudocercospora heteropyxidicola on leaf spots of Heteropyxis natalensis, Pseudopenidiella podocarpi,Scolecobasidium podocarpi and Ceramothyrium podocarpicola on leaves of Podocarpus latifolius, Scolecobasidiumblechni on leaves of Blechnum capense, Stomiopeltis syzygii on leaves of Syzygium chordatum, Strelitziomycesknysnanus (incl. Strelitziomyces gen. nov.) on leaves of Strelitzia alba, Talaromyces clemensii from rotting wood ingoldmine, Verrucocladosporium visseri on Carpobrotus edulis. Spain, Boletopsis mediterraneensis on soil, Calycinacortegadensisi on a living twig of Castanea sativa, Emmonsiellopsis tuberculata in fluvial sediments, Mollisia cortegadensison dead attached twig of Quercus robur, Psathyrella ovispora on soil, Pseudobeltrania lauri on leaf litterof Laurus azorica, Terfezia dunensis in soil, Tuber lucentum in soil, Venturia submersa on submerged plant debris.Thailand, Cordyceps jakajanicola on cicada nymph, Cordyceps kuiburiensis on spider, Distoseptispora caricis onleaves of Carex sp., Ophiocordyceps khonkaenensis on cicada nymph. USA, Cytosporella juncicola and Davidiellomycesjuncicola on culms of Juncus effusus, Monochaetia massachusettsianum from air sample, Neohelicomycesmelaleucae and Periconia neobrittanica on leaves of Melaleuca styphelioides x lanceolata, Pseudocamarosporiumeucalypti on leaves of Eucalyptus sp., Pseudogymnoascus lindneri from sediment in a mine, Pseudogymnoascusturneri from sediment in a railroad tunnel, Pulchroboletus sclerotiorum on soil, Zygosporium pseudomasonii onleaf of Serenoa repens. Vietnam, Boletus candidissimus and Veloporphyrellus vulpinus on soil. Morphological andculture characteristics are supported by DNA barcodes.
|
|
| 30. |
- Da Silveira, G. Gil, et al.
(författare)
-
Exclusive vector meson photoproduction at the LHC and a future circular collider : A closer look on the final state
- 2017
-
Ingår i: Physical Review D. - 2470-0010. ; 95:3
-
Tidskriftsartikel (refereegranskat)abstract
- Over the past years, the LHC experiments have reported experimental evidence for processes associated to photon-photon and photon-hadron interactions, showing their potential to investigate the production of low- and high-mass systems in exclusive events. In the particular case of the photoproduction of vector mesons, the experimental study of this final state is expected to shed light on the description of the QCD dynamics at small values of the Bjorken-x variable. In this paper, we extend previous studies for the exclusive J/Ψ and photoproduction in pp collisions based on the nonlinear QCD dynamics by performing a detailed study of the final-state distributions that can be measured experimentally at the LHC and at a future circular collider. Predictions for the rapidity and transverse momentum distributions of the vector mesons and of final-state dimuons are presented for pp collisions at s=7, 13, and 100 TeV.
|
|
| 31. |
- Emami, Nazanin, et al.
(författare)
-
Biotribolological behaviour of reinforced UHMWPE
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Carbon nanoforms exhibit exceptional physical and chemical properties due to their nano-scale dimensions. They also have very high aspect ratio which makes them an excellent reinforcement material for polymer composites. Hydroxyapatite (HA) is the prime constituent of bone generation because of its ability to bond chemically with living bone tissues and positively affect the osteoblasts; this is due to its similar chemical composition and crystal structure to apatite in the human skeletal system. Ultra high molecular weight polyethylene (UHMWPE) is already used as implant material in high stress bearing areas such as hip and knee prosthesis. Wear debris of ultra high molecular weight polyethylene cause osteolysis which is a major reason of long-term failure of total hip replacements. In this study carbon nanoforms together with hydroxyapatite (HA) nanoparticles were used as reinforcement in UHMWPE matrix in order to produce high strength and wear resistant biocomposite with better bioactivity character. Solvent casting and melt blending methods were used during the preparation of this bio-nano composite. The manufacturing process was studied using different characterization methods such as diferencial scanning calorimetry (DSC), scanning electron microscopy (SEM) and Raman-spectroscopy. The tribological behaviour of the manufactured bio-nano composite was studied using pin-on-plate method. Wear and friction of the produced novel composite were studied in different biological lubrications. Different lubrication affected the friction rate and wear, though the results were not statistically different. The reinforced UHMWPE showed superior tribology behaviour in comparison to pure UHMWPE (p>0.05).
|
|
| 32. |
- Emami, Nazanin, et al.
(författare)
-
Novel bio nano-composite for biomedical application
- 2010
-
Ingår i: 14th Nordic Symposium on Tribology. - Luleå : Luleå tekniska universitet. - 9789174391244
-
Konferensbidrag (refereegranskat)abstract
- Carbon nanoforms exhibit exceptional physical and chemical properties due to their nano-scale dimensions. They also have very high aspect ratio which makes them an excellent reinforcement material for polymer composites. Hydroxyapatite (HA) is the prime constituent of bone generation because of its ability to bond chemically with living bone tissues and positively affect the osteoblasts; this is due to its similar chemical composition and crystal structure to apatite in the human skeletal system. Ultra high molecular weight polyethylene (UHMWPE) is already used as implant material in high stress bearing areas such as hip and knee prosthesis. Wear debris of ultra high molecular weight polyethylene cause osteolysis which is a major reason of long-term failure of total hip replacements.In this study carbon nanoforms together with hydroxyapatite (HA) nanoparticles were used as reinforcement in UHMWPE matrix in order to produce high strength and wear resistant biocomposites with better bioactivity character. Solvent casting and melt blending methods was used during the preparation of this bio-nano composite. The phase compositions and the surface morphology of the nanocomposite material have been studied using X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), and micro-Raman spectroscopy. Nanoindentation technique was used to determine the elastic modulus and hardness of the nanocomposites with different weight% of HA and carbonnanoforms concentrations. The tribologic behaviour of this nano composite was studied using pin-on-plate method. Wear and friction of the produced nano-composites were studied in different biological lubrications.
|
|
| 33. |
|
|
| 34. |
- Enqvist, Evelina, et al.
(författare)
-
Optimisation of manufacturing process of UHMWPE/nanoHA/MWCNTs
- 2010
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Hip- and knee replacements are amongst the most common performed surgical operations performed today. Ultra high molecular weight polyethylene (UHMWPE) is frequently used for joint-replacements due to its excellent properties such as high impact strength, toughness and low friction. Wear debris produced when UHMWPE is sliding against a metal counter face is one of the major causes of total failure of implant as an effect of wear debris induced osteolysis. The nano scale dimensions of Carbon nanotubes (CNTs) give them unique physical and chemical properties. Their high aspect ratio makes them perfect as reinforcement in composite materials. Hydroxyapatite (HA) is similar in chemical composition and structure to apatite naturally occurring in human bone tissue and is thus positively affecting bone integration. However the brittleness and poor strength of HA limits the use of HA in load-bearing areas. This work focuses on the manufacturing of a new CNT and HA reinforced UHMWPE bio nanocomposite, using solvent casting and a melt-mixing method. Hot press was used to fabricate the final sample. The produced bio-nanocomposite was characterized by use of differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and micro-Raman spectroscopy. Nanoindentation was used to study the hardness and elastic modulus of samples containing CNTs and different HA loading.
|
|
| 35. |
- Gonçalves, Gil, et al.
(författare)
-
Breakdown into nanoscale of graphene oxide : Confined hot spot atomic reduction and fragmentation
- 2014
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Nano-graphene oxide (nano-GO) is a new class of carbon based materials being proposed for biomedical applications due to its small size, intrinsic optical properties, large specific surface area, and easy to functionalize. To fully exploit nano-GO properties, a reproducible method for its production is of utmost importance. Herein we report, the study of the sequential fracture of GO sheets onto nano-GO with controllable lateral width, by a simple, and reproducible method based on a mechanism that we describe as a confined hot spot atomic fragmentation/reduction of GO promoted by ultrasonication. The chemical and structural changes on GO structure during the breakage were monitored by XPS, FTIR, Raman and HRTEM. We found that GO sheets starts breaking from the defects region and in a second phase through the disruption of carbon bonds while still maintaining crystalline carbon domains. The breaking of GO is accompanied by its own reduction, essentially by the elimination of carboxylic and carbonyl functional groups. Photoluminescence and photothermal studies using this nano-GO are also presented highlighting the potential of this nanomaterial as a unique imaging/therapy platform
|
|
| 36. |
- Goncalves, Gil, et al.
(författare)
-
Graphene oxide modified with PMMA via ATRP as a reinforcement filler
- 2010
-
Ingår i: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 40:44, s. 9927-9934
-
Tidskriftsartikel (refereegranskat)abstract
- Graphene is a two-dimensional new allotrope of carbon, which is stimulating great curiosity due to its superior mechanical, electrical, thermal and optical properties. Particularly attractive is the availability of bulk quantities of graphene (G) which can be easily processed by chemical exfoliation, yielding graphene oxide (GO). The resultant oxygenated graphene sheets covered with hydroxyl, epoxy and carboxyl groups offer tremendous opportunities for further functionalization opening plenty of opportunities for the preparation of advanced composite materials. In this work poly(methyl methacrylate) (PMMA) chains have been grafted from the GO surface via atom transfer radical polymerization (ATRP), yielding a nanocomposite which was soluble in chloroform. The surface of the PMMA grafted GO (GPMMA) was characterized by AFM, HRTEM, Raman, FTIR and contact angle. The interest of these novel nanocomposites lies in their potential to be homogenously dispersed in polymeric dense matrices and to promote good interfacial adhesion, of particular relevance in stress transfer to the fillers. PMMA composite films were prepared using different percentages of GPMMA and pristine GO. Mechanical analysis of the resulting films showed that loadings as low as 1% (w/w) of GPMMA are effective reinforcing agents, yielding tougher films than pure PMMA films and even than composite films of PMMA prepared with GO. In fact, addition of 1% (w/w) of GPMMA fillers led to a significant improvement of the elongation at break, yielding a much more ductile and therefore tougher material. Thermal analysis showed an increase of the thermal stability properties of these films providing evidence that strong interfacial interactions between PMMA and GPMMA are achieved. In addition, AFM analysis, in friction force mode, is demonstrated to be an effective tool to analyse the surface filler distribution on polymer matrices
|
|
| 37. |
- Henriques, Bruno, et al.
(författare)
-
Optimized graphene oxide foam with enhanced performance and high selectivity for mercury removal from water
- 2016
-
Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 301, s. 453-461
-
Tidskriftsartikel (refereegranskat)abstract
- This work explores the preparation of three-dimensional graphene oxide macroscopic structures, shaped by self-assembling single graphene oxide (3DGO) sheets with control of its surface chemistry by combining with nitrogen functional groups (3DGON), or with nitrogen and sulphur functional groups (3DGOSN), and their application in the removal of mercury (Hg(II)) from aqueous solutions. The chemical structure of the materials was assessed by using different characterization techniques: SEM, XPS and BET. Adsorption studies conducted in Hg(II) contaminated ultra-pure water reveal the enhanced ability of 3DGON for the adsorption of this metal, when compared to the other GO foams. A small dose of 3DGON (10 mg L−1) allows to remove up to 96% of Hg(II) after 24 h of contact time, leading to a residual concentration in solution close to the guideline value for drinking water (1 μg L−1). The ability of this material to adsorb Hg (II) was evaluated relatively to different experimental parameters such as pH, sorbent dose, time and effect on different competing metal ions. Real application was also evaluated by testing its performance in two different natural matrices, river and sea water, with very promising results.
|
|
| 38. |
- Joffrin, E., et al.
(författare)
-
Overview of the JET preparation for deuterium-tritium operation with the ITER like-wall
- 2019
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 59:11
-
Forskningsöversikt (refereegranskat)abstract
- For the past several years, the JET scientific programme (Pamela et al 2007 Fusion Eng. Des. 82 590) has been engaged in a multi-campaign effort, including experiments in D, H and T, leading up to 2020 and the first experiments with 50%/50% D-T mixtures since 1997 and the first ever D-T plasmas with the ITER mix of plasma-facing component materials. For this purpose, a concerted physics and technology programme was launched with a view to prepare the D-T campaign (DTE2). This paper addresses the key elements developed by the JET programme directly contributing to the D-T preparation. This intense preparation includes the review of the physics basis for the D-T operational scenarios, including the fusion power predictions through first principle and integrated modelling, and the impact of isotopes in the operation and physics of D-T plasmas (thermal and particle transport, high confinement mode (H-mode) access, Be and W erosion, fuel recovery, etc). This effort also requires improving several aspects of plasma operation for DTE2, such as real time control schemes, heat load control, disruption avoidance and a mitigation system (including the installation of a new shattered pellet injector), novel ion cyclotron resonance heating schemes (such as the three-ions scheme), new diagnostics (neutron camera and spectrometer, active Alfven eigenmode antennas, neutral gauges, radiation hard imaging systems...) and the calibration of the JET neutron diagnostics at 14 MeV for accurate fusion power measurement. The active preparation of JET for the 2020 D-T campaign provides an incomparable source of information and a basis for the future D-T operation of ITER, and it is also foreseen that a large number of key physics issues will be addressed in support of burning plasmas.
|
|
| 39. |
- Kneissl, Lucas M., et al.
(författare)
-
Mechanical properties and tribological performance of polyoxymethylene/short cellulose fiber composites
- 2023
-
Ingår i: Polymer testing. - : Elsevier Ltd. - 0142-9418 .- 1873-2348. ; 128
-
Tidskriftsartikel (refereegranskat)abstract
- Natural fibers are promising bio-based materials to use as reinforcements in polymer composites as often more affordable and accessible alternatives to fossil-based fibers, especially because of their superior sustainability. Polyoxymethylene (POM) is a widely used engineering thermoplastic, which has a melting temperature suitable for processing with natural fibers. In this study, such composites consisting of POM and regenerated cellulose fibers have been developed and studied in terms of their mechanical, thermal, tribological and structural properties. Tensile and flexural moduli increased with incorporation of 30 wt% fibers up to 89% and 79% respectively, crystallinity increased as well by a maximum of approx. 11% at 30% fiber content. Furthermore, the specific wear rate was improved for the composite with 10 wt% fibers, showing a decrease of roughly 80%. This study investigates the processing parameters and tribo-mechanical performance of POM-based natural fiber composites as an important route towards future sustainable polymer composites in load bearing applications.
|
|
| 40. |
- Maffini, Ana Luisa, et al.
(författare)
-
Inequalities in the potential movement of social groups: A network-based indicator
- 2024
-
Ingår i: Environment and Planning B: Urban Analytics and City Science. - 2399-8091 .- 2399-8083. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- Accessibility and mobility are key concerns of sustainable cities, especially in the Global South, due to the strong social inequalities. This paper contributes to the literature on mobility segregation by focusing on the potential movement of social groups in the city. We conceptualize potential movement as a network centrality, acting as an indicator of population movement when performing daily activities (working, studying, shopping, etc.). This paper's objectives are (a) to identify the inequalities in potential movement of different social groups performing their daily activities; (b) to propose a network-based method to enhance our understanding of mobility inequalities; and (c) to address the context of medium-sized Latin American cities. We adopt a modified Betweenness Centrality model (Potential Movement) on a directed and weighted network. Our results show a similar pattern for both cities, with the CBD concentrating the potential movement for all groups; however, several inequalities were found. The high-income and white groups show higher levels of potential movement in the CBD and the low-income and non-white groups have a more distributed potential movement pattern, implying longer journeys to reach jobs and services. Income and race have shown to play a crucial role in those inequalities.
|
|
| 41. |
- Murari, A., et al.
(författare)
-
A control oriented strategy of disruption prediction to avoid the configuration collapse of tokamak reactors
- 2024
-
Ingår i: Nature Communications. - 2041-1723 .- 2041-1723. ; 15:1
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of thermonuclear fusion consists of producing electricity from the coalescence of light nuclei in high temperature plasmas. The most promising route to fusion envisages the confinement of such plasmas with magnetic fields, whose most studied configuration is the tokamak. Disruptions are catastrophic collapses affecting all tokamak devices and one of the main potential showstoppers on the route to a commercial reactor. In this work we report how, deploying innovative analysis methods on thousands of JET experiments covering the isotopic compositions from hydrogen to full tritium and including the major D-T campaign, the nature of the various forms of collapse is investigated in all phases of the discharges. An original approach to proximity detection has been developed, which allows determining both the probability of and the time interval remaining before an incoming disruption, with adaptive, from scratch, real time compatible techniques. The results indicate that physics based prediction and control tools can be developed, to deploy realistic strategies of disruption avoidance and prevention, meeting the requirements of the next generation of devices.
|
|
| 42. |
|
|
| 43. |
|
|
| 44. |
- Peltola, Jukka, et al.
(författare)
-
Deep Brain Stimulation of the Anterior Nucleus of the Thalamus in Drug-Resistant Epilepsy in the MORE Multicenter Patient Registry
- 2023
-
Ingår i: Neurology. - : Wolters Kluwer. - 0028-3878 .- 1526-632X. ; 100:18, s. E1852-E1865
-
Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives The efficacy of deep brain stimulation of the anterior nucleus of the thalamus (ANT DBS) in patients with drug-resistant epilepsy (DRE) was demonstrated in the double-blind Stimulation of the Anterior Nucleus of the Thalamus for Epilepsy randomized controlled trial. The Medtronic Registry for Epilepsy (MORE) aims to understand the safety and longer-term effectiveness of ANT DBS therapy in routine clinical practice.Methods MORE is an observational registry collecting prospective and retrospective clinical data. Participants were at least 18 years old, with focal DRE recruited across 25 centers from 13 countries. They were followed for at least 2 years in terms of seizure frequency (SF), responder rate (RR), health-related quality of life (Quality of Life in Epilepsy Inventory 31), depression, and safety outcomes.Results Of the 191 patients recruited, 170 (mean [SD] age of 35.6 [10.7] years, 43% female) were implanted with DBS therapy and met all eligibility criteria. At baseline, 38% of patients reported cognitive impairment. The median monthly SF decreased by 33.1% from 15.8 at baseline to 8.8 at 2 years (p < 0.0001) with 32.3% RR. In the subgroup of 47 patients who completed 5 years of follow-up, the median monthly SF decreased by 55.1% from 16 at baseline to 7.9 at 5 years (p < 0.0001) with 53.2% RR. High-volume centers (>10 implantations) had 42.8% reduction in median monthly SF by 2 years in comparison with 25.8% in low-volume center. In patients with cognitive impairment, the reduction in median monthly SF was 26.0% by 2 years compared with 36.1% in patients without cognitive impairment. The most frequently reported adverse events were changes (e.g., increased frequency/severity) in seizure (16%), memory impairment (patient-reported complaint, 15%), depressive mood (patient-reported complaint, 13%), and epilepsy (12%). One definite sudden unexpected death in epilepsy case was reported.Discussion The MORE registry supports the effectiveness and safety of ANT DBS therapy in a real-world setting in the 2 years following implantation.Classification of Evidence This study provides Class IV evidence that ANT DBS reduces the frequency of seizures in patients with drug-resistant focal epilepsy.
|
|
| 45. |
- Pinto, Rui, et al.
(författare)
-
Attack Detection in Cyber-Physical Production Systems using the Deterministic Dendritic Cell Algorithm
- 2020
-
Ingår i: Proceedings. - : IEEE. ; , s. 1552-1559
-
Konferensbidrag (refereegranskat)abstract
- Cyber-Physical Production Systems (CPPS) are key enablers for industrial and economic growth. The introduction of the Internet of Things (IoT) in industrial processes represents a new revolution towards the Smart Manufacturing oncept and is usually designated as the 4 th Industrial Revolution. Despite the huge interest from the industry to innovate their production systems, in order to increase revenues at lower costs, the IoT concept is still immature and fuzzy, which increases security related risks in industrial systems. Facing this paradigm and, since CPPS have reached a level of complexity, where the human intervention for operation and control is becoming increasingly difficult, Smart Factories require autonomic methodologies for security management and self-healing. This paper presents an Intrusion Detection System (IDS) approach for CPPS, based on the deterministic Dendritic Cell Algorithm (dDCA). To evaluate the dDCA effectiveness, a testing dataset was generated, by implementing and injecting various attacks on a OPC UA based CPPS testbed. The results show that these attacks can be successfully detected using the dDCA.
|
|
| 46. |
- Pinto, Rui, et al.
(författare)
-
Enabling data-driven anomaly detection by design in cyber-physical production systems
- 2022
-
Ingår i: Cybersecurity. - : Springer Nature. - 2523-3246. ; 5
-
Tidskriftsartikel (refereegranskat)abstract
- Designing and developing distributed cyber-physical production systems (CPPS) is a time-consuming, complex, and error-prone process. These systems are typically heterogeneous, i.e., they consist of multiple components implemented with different languages and development tools. One of the main problems nowadays in CPPS implementation is enabling security mechanisms by design while reducing the complexity and increasing the system’s maintainability. Adopting the IEC 61499 standard is an excellent approach to tackle these challenges by enabling the design, deployment, and management of CPPS in a model-based engineering methodology. We propose a method for CPPS design based on the IEC 61499 standard. The method allows designers to embed a bio-inspired anomaly-based host intrusion detection system (A-HIDS) in Edge devices. This A-HIDS is based on the incremental Dendritic Cell Algorithm (iDCA) and can analyze OPC UA network data exchanged between the Edge devices and detect attacks that target the CPPS’ Edge layer. This study’s findings have practical implications on the industrial security community by making novel contributions to the intrusion detection problem in CPPS considering immune-inspired solutions, and cost-effective security by design system implementation. According to the experimental data, the proposed solution can dramatically reduce design and code complexity while improving application maintainability and successfully detecting network attacks without negatively impacting the performance of the CPPS Edge devices.
|
|
| 47. |
- Pinto, Rui, et al.
(författare)
-
Incremental Dendritic Cell Algorithm for Intrusion Detection in Cyber-Physical Production Systems
- 2021
-
Ingår i: Intelligent Computing. - Cham : Springer. ; , s. 664-680
-
Konferensbidrag (refereegranskat)abstract
- Cyber-Physical Production Systems (CPPS) are becoming increasingly more susceptible to security vulnerabilities, specially with the introduction of IoT principles in manufacturing scenarios. Since security is crucial to the development and acceptance of CPPS, flexible adaptation to real CPPS security environment and reasonable response to real-time CPPS security events are needed. This paper presents an Intrusion Detection System (IDS) approach for CPPS, based on an extended version of the Dendritic Cell Algorithm (DCA), designated as Incremental Dendritic Cell Algorithm (iDCA). Facing the industrial requirements for intrusion detection and response, the proposed solution enables online incremental detection in an unsupervised manner. Results show that the approach is a viable solution to detect anomalies in (near) real-time, specially in environments with little a priori system knowledge for intrusion detection.
|
|
| 48. |
- Romanelli, F, et al.
(författare)
-
Overview of the JET results
- 2011
-
Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 51:9
-
Tidskriftsartikel (refereegranskat)abstract
- Since the last IAEA Conference JET has been in operation for one year with a programmatic focus on the qualification of ITER operating scenarios, the consolidation of ITER design choices and preparation for plasma operation with the ITER-like wall presently being installed in JET. Good progress has been achieved, including stationary ELMy H-mode operation at 4.5 MA. The high confinement hybrid scenario has been extended to high triangularity, lower ρ*and to pulse lengths comparable to the resistive time. The steady-state scenario has also been extended to lower ρ*and ν*and optimized to simultaneously achieve, under stationary conditions, ITER-like values of all other relevant normalized parameters. A dedicated helium campaign has allowed key aspects of plasma control and H-mode operation for the ITER non-activated phase to be evaluated. Effective sawtooth control by fast ions has been demonstrated with3He minority ICRH, a scenario with negligible minority current drive. Edge localized mode (ELM) control studies using external n = 1 and n = 2 perturbation fields have found a resonance effect in ELM frequency for specific q95values. Complete ELM suppression has, however, not been observed, even with an edge Chirikov parameter larger than 1. Pellet ELM pacing has been demonstrated and the minimum pellet size needed to trigger an ELM has been estimated. For both natural and mitigated ELMs a broadening of the divertor ELM-wetted area with increasing ELM size has been found. In disruption studies with massive gas injection up to 50% of the thermal energy could be radiated before, and 20% during, the thermal quench. Halo currents could be reduced by 60% and, using argon/deuterium and neon/deuterium gas mixtures, runaway electron generation could be avoided. Most objectives of the ITER-like ICRH antenna have been demonstrated; matching with closely packed straps, ELM resilience, scattering matrix arc detection and operation at high power density (6.2 MW m-2) and antenna strap voltages (42 kV). Coupling measurements are in very good agreement with TOPICA modelling. © 2011 IAEA, Vienna.
|
|
| 49. |
- Schael, S, et al.
(författare)
-
Precision electroweak measurements on the Z resonance
- 2006
-
Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 50. |
- Somberg, Julian, et al.
(författare)
-
Chemically expanded graphite-based ultra-high molecular weight polyethylene nanocomposites with enhanced mechanical properties
- 2022
-
Ingår i: Materials & design. - : Elsevier Ltd. - 0264-1275 .- 1873-4197. ; 224
-
Tidskriftsartikel (refereegranskat)abstract
- Chemically expanded graphite (CEG) has recently been identified as promising reinforcement for polymer composites with the ability for commercial up-scaling. In this work, silane and polydopamine functionalized CEG were successfully synthesized and employed to prepare ultra-high molecular weight polyethylene (UHMWPE) nanocomposites with an enhanced interfacial compatibility. Characterisation of the functionalized CEG indicated a significant oxygen reduction, which gave rise to a restoration of the graphitic structure. The polydopamine functionalized CEG showed an enhanced exfoliation and dispersion in organic solvents and the polymer matrix with respect to the non-modified CEG. The silane functionalized CEG provided a higher affinity towards the matrix with polymer chains covering the CEG sheets on the fracture surfaces. The addition of functionalized CEG enhanced the mechanical properties of the UHMWPE matrix with an increase in micro-hardness of up to 25% and storage modulus of up to 58%. Furthermore, the hydrophobicity of the composites was significantly enhanced with an increase in water contact angle from 98.6° for the pure polymer to 119° for 5 wt% silane functionalized CEG. Preliminary wear experiments indicated the potential of the composites for tribological applications with a decrease in wear rate of up to 99% under water lubricated conditions.
|
|
