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  • 51.
    Andersson, Ida
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för ämnesdidaktik och matematik.
    Hur har digitaliseringen i skolan förändrat kemiundervisningen i årskurs 7-9?: En jämförelse mellan forskning och praktik2018Independent thesis Advanced level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I den reviderade variation av LGR 11 (Läroplan för grundskolan, förskoleklassen ochfritidshemmet 2011) från 2017 lyfts digitaliseringen fram. Skolan är under förändringoch digitala verktyg finns i klassrum. Eleverna förväntas använda dessa och utvecklaförmågor som lyfts fram i LGR 11 och utveckla kunskaper om hur de ska förhålla sigtill ett konstant informationsflöde. Samtidigt använder lärare redan idag många digitalaverktyg i sin undervisning. Med de förändringar som gjorts markerar myndigheter iSverige vikten av att eleverna lär sig navigera och hantera den digitala världen.Frågan som då måste ställas är hur det ser ut i klassrum i Sverige och hurdigitaliseringen har påverkat undervisningen i kemi. När datorn gjorde entréförändrades klassrummet men det tog tid. Idag finns det en mängd olika digitalaverktyg att använda. Genom att gå ut och intervjua lärare skapades en bild avsituationen i det digitala kemiklassrummet. De arbetade med digitala böcker,interaktiva övningar och formativ feedback via delade dokument. Digitaliseringen iskolan speglar den utveckling som samhället har tagit och det är viktigt att alla få följamed i den utvecklingen.Det har även bedrivits forskning inom digitaliseringen i skolan där begrepp som digitalläsning återfinns. Hur har undervisningen hanterats i förhållande till den forskningsom finns och hur lyfter digitaliseringen undervisningen? Genom att göra en jämförelsemellan forskning och praktik skapas en bild av hur det ser ut i skolor men också varmöjligheter för utveckling ligger.

    Fulltekst (pdf)
    fulltext
  • 52.
    Andersson, Magnus
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Axner, Ove
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Almqvist, Fredrik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Uhlin, Bernt Eric
    Umeå universitet, Medicinska fakulteten, Institutionen för molekylärbiologi (Medicinska fakulteten).
    Fällman, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Physical Properties of Biopolymers Assessed by Optical Tweezers: Analysis of folding and refolding of bacterial pili2008Inngår i: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 9, nr 2, s. 221-235Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Bacterial adhesion to surfaces mediated by specific adhesion organelles that promote infections, as exemplified by the pili of uropathogenic E. coli, is studied mostly at the level of cell-cell interactions and thereby reflects the averaged behavior of multiple pili. The role of pilus rod structure has therefore only been estimated from the outcome of experiments involving large numbers of organelles at the same time. It has, however, lately become clear that the biomechanical behavior of the pilus shafts play an important, albeit hitherto rather unrecognized, role in the adhesion process. For example, it has been observed that shafts from two different strains, even though they are similar in structure, result in large differences in the ability of the bacteria to adhere to their host tissue. However, in order to identify all properties of pilus structures that are of importance in the adhesion process, the biomechanical properties of pili must be assessed at the single-molecule level. Due to the low range of forces of these structures, until recently it was not possible to obtain such information. However, with the development of force-measuring optical tweezers (FMOT) with force resolution in the low piconewton range, it has lately become possible to assess forces mediated by individual pili on single living bacteria in real time. FMOT allows for a more or less detailed mapping of the biomechanical properties of individual pilus shafts, in particular those that are associated with their elongation and contraction under stress. This Mi- nireview presents the FMOT technique, the biological model system, and results from assessment of the biomechanical properties of bacterial pili. The information retrieved is also compared with that obtained by atomic force microscopy.

  • 53.
    Andersson, Nina
    et al.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Corkery, Robert W.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Alberius, Peter C. A.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    One-pot synthesis of well ordered mesoporous magnetic carriers2007Inngår i: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 17, nr 26, s. 2700-2705Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The facile preparation of a mesoporous magnetic carrier technology is demonstrated. The micron-sized spherical mesostructured particles are prepared using a newly-developed, one-step, combined emulsion and solvent evaporation (ESE) method. The surfactant-templated silica matrix display a well-ordered internal pore architecture. Very limited pore blocking, and only to a limited degree disordered- or worm-like structures are observed, induced by the iron oxide nanoparticles added to provide the superparamagnetic properties.The iron oxide content was precisely controlled, and themagnetic properties were well preserved during the process. Finally we demonstrate the applicability of the magnetically separable mesoporous material as an adsorbent for specific dissolved materials from dilute aqueous solutions.

  • 54.
    Andersson, Nina
    et al.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Kronberg, Bengt
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Corkery, Robert W.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Alberius, Peter
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Combined Emulsion and Solvent Evaporation (ESE) Synthesis Route to Well-Ordered Mesoporous Materials2007Inngår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 23, nr 3, s. 1459-1464Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Control over morphol. and internal mesostructure of surfactant templated silicas remains a challenge, esp. when considering scaling lab. syntheses up to industrial vols. Here we report a method combining emulsification with the evapn.-induced self-assembly (EISA) method for prepg. spherical, mesoporous silica particles. This emulsion and solvent evapn. (ESE) method has several potential advantages over classic pptn. routes: it is easily scaled while providing superior control over stoichiometric homogeneity of templating surfactants and inorg. precursors, and particle sizes and distributions are detd. by principles developed for manipulating droplet sizes within water-in-oil emulsions. To demonstrate the method, triblock copolymer P104 is used as a templating amphiphile, generating unusually well-ordered 2D hexagonal (P6mm) mesoporous silica, while particle sizes and morphologies were controlled by varying the type of emulsifier and the method for emulsification. [on SciFinder(R)]

  • 55. Andrii, Dudnyk
    et al.
    Matthew, Burman
    Ludmyla, Kulyk
    Olena, Rzhepishevska
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Umeå universitet, Medicinska fakulteten, Institutionen för klinisk mikrobiologi.
    M/XDR‐TB treatment perspective: how to avoid mountains of pills via digital technologies2018Inngår i: Respirology (Carlton South. Print), ISSN 1323-7799, E-ISSN 1440-1843, Vol. 23, nr 6, s. 636-637Artikkel i tidsskrift (Fagfellevurdert)
  • 56.
    Andrén, Daniel
    et al.
    Department of Physics, Chalmers University of Technology, Göteborg, Sweden.
    Shao, Lei
    Department of Physics, Chalmers University of Technology, Göteborg, Sweden.
    Länk, Nils Odebo
    Department of Physics, Chalmers University of Technology, Göteborg, Sweden.
    Acimovic, Srdjan S.
    Department of Physics, Chalmers University of Technology, Göteborg, Sweden.
    Johansson, Peter
    Örebro universitet, Institutionen för naturvetenskap och teknik. Department of Physics, Chalmers University of Technology, Göteborg, Sweden.
    Käll, Mikael
    Department of Physics, Chalmers University of Technology, Göteborg, Sweden.
    Probing Photothermal Effects on Optically Trapped Gold Nanorods by Simultaneous Plasmon Spectroscopy and Brownian Dynamics Analysis2017Inngår i: ACS Nano, ISSN 1936-0851, E-ISSN 1936-086X, Vol. 11, nr 10, s. 10053-10061Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Plasmonic gold nanorods are prime candidates for a variety of biomedical, spectroscopy, data storage, and sensing applications. It was recently shown that gold nanorods optically trapped by a focused circularly polarized laser beam can function as extremely efficient nanoscopic rotary motors. The system holds promise for-applications ranging from nanofluidic flow control and nanorobotics to biomolecular actuation and analysis. However, to fully exploit this potential, one needs to be able to control and understand heating effects associated with laser trapping. We investigated photothermal heating of individual rotating gold nanorods by simultaneously probing their localized surface plasmon resonance spectrum and rotational Brownian dynamics over extended periods of time. The data reveal an extremely slow nanoparticle reshaping process, involving migration of the order of a few hundred atoms per minute, for moderate laser powers and a trapping wavelength close to plasmon resonance. The plasmon spectroscopy and Brownian analysis allows for separate temperature estimates based on the refractive index and the viscosity of the water surrounding a trapped nanorod. We show that both measurements yield similar effective temperatures, which correspond to the actual temperature at a distance of the order 10-15 nm from the particle surface. Our results shed light on photothermal processes on the nanoscale and will be useful in evaluating the applicability and performance of nanorod motors and optically heated nanoparticles for a variety of applications.

  • 57.
    Angizi, Shayan
    et al.
    McMaster Univ, Canada.
    Khalaj, Maryam
    Imam Khomeini Int Univ, Iran.
    Alem, Sayed Ali Ahmad
    Politecn Milan, Italy.
    Pakdel, Amir
    Trinity Coll Dublin, Ireland.
    Willander, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik, elektroteknik och matematik. Linköpings universitet, Tekniska fakulteten.
    Hatamie, Amir
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska fakulteten. Univ Gothenburg, Sweden; Sharif Univ Technol, Iran.
    Simchi, Abdolreza
    Sharif Univ Technol, Iran.
    Review-Towards the Two-Dimensional Hexagonal Boron Nitride (2D h-BN) Electrochemical Sensing Platforms2020Inngår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 167, nr 12, artikkel-id 126513Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Electrochemical sensing performance of two-dimensional hexagonal boron nitride (2D h-BN) has traditionally been suppressed by their intrinsic electrical insulation and deficient electron transportation mechanism. However, the excellent electrocatalytic activity, high specific surface area, N- and B-active edges, structural defects, adjustable band gap through interaction with other nanomaterials, and chemical functionalization, makes 2D h-BN ideal for many sensing applications. Therefore, finding a pathway to modulate the electronic properties of 2D h-BN while the intrinsic characteristics are well preserved, will evolve a new generation of highly sensitive and selective electrochemical (bio)sensors. That is why extensive research has recently focused on the challenge to functionalize 2D h-BN by controlling the surface chemical reactions with external species, particularly metal nanoparticles. This review summarizes the most recent progress in the application of 2D h-BN nanosheets in electrochemical (bio)sensing. We will explore the fabrication techniques of 2D h-BN for electrochemical applications followed by thorough discussion on their advantages, shortcomings, and promising possibilities as (bio)sensing platforms in near future.

    Fulltekst (pdf)
    fulltext
  • 58.
    Ankerfors, Caroline
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Johansson, Erik
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Pettersson, Torbjörn
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Use of polyelectrolyte complexes and multilayers from polymers and nanoparticles to create sacrificial bonds between surfaces2013Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 391, s. 28-35Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, particle polyelectrolyte complexes (PPECs) were formed by mixing cationic polyacrylamide (CPAM) and silica nanoparticles using the jet mixing technique. Within certain limits, the size of the formed PPECs could be controlled. The aim was to prepare PPECs with embedded sacrificial bonds, similar to those found in bones. Examination of PPEC adsorption to silica model surfaces indicated that,smaller PPECs adsorbed to a higher level than larger ones, due to the higher diffusion speed of smaller complexes. Adsorption studies of the same components as in the PPECs, but arranged in multilayers, that is, particle polyelectrolyte multilayers (PPEMs), indicated a stable, gradual build-up of material on the surface with smaller nanoparticles, whereas PPEMs comprising elongated nanoparticles appeared to be more loosely adsorbed onto the surface when the nanoparticles were in the outer layer, due to repulsive forces within the adsorbed layer. The AFM colloidal probe technique was used to study the interaction between surfaces treated with PPECs, multilayers, or polyelectrolyte complexes (PECs). The results showed that the expected long-range disentanglement could be achieved with PPECs but that the pull-off forces were generally low. Treatment with PPEMs comprising the same polymer and nanoparticle components produced higher pull-off values, together with disentanglement behaviour, possibly due to better contact between the surfaces. Adhesion experiments with polymer PECs showed significantly higher pull-off values than with the PPECs, probably due to polymer interdiffusion across the surface boundary.

  • 59. Annergren, Göran
    et al.
    Kvarnlöf, Niklas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper.
    Sulfitmassa: Översikt kring Processfrågor, Marknad och Framtid2014Rapport (Annet vitenskapelig)
    Abstract [sv]

    Karlstads universitet har tagit på sig uppgiften att försöka sammanställa det kunnande som idag finns inom landet kring sulfitmassa och sulfitprocesser. Eftersom antalet massabruk som tillverkar sulfitmassa sakta sjunker är detta en viktig uppgift för att i någon mån kunna behålla det stora kunnande som en gång fanns kring denna process.

    Denna rapport belyser bl.a. viktiga processfrågor kring framställningen av pappers- och dissolvingmassor från sulfitprocessen.

    Fulltekst (pdf)
    Sulfitmassa_KUS2014_22
  • 60.
    Anoshkin, Ilya
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Mikro- och nanosystemteknik.
    Nefedova, Irina
    Lioubtchenko, Dmitri
    KTH, Skolan för elektro- och systemteknik (EES), Mikro- och nanosystemteknik.
    Nefedov, Igor
    Räisänen, Antti
    Single walled carbon nanotube quantification method employing the Raman signal intensity2017Inngår i: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 116, s. 547-552Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new technique for measuring the number of single walled carbon nanotubes (SWCNTs) and their concentration in a carbon nanotube layer is developed in this work. It is based on the G peak intensity of the Raman spectrum, together with precise mass and optical absorbance measurements. The dependence of the number of the carbon nanotubes on the phonon scattering intensity is observed. This method opens an opportunity for the quantitative mapping of sp2 carbon atom distribution in the SWCNT layers with a resolution limited by the focused laser spot size.

  • 61.
    Ansari, Farhan
    et al.
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Galland, Sylvain
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Johansson, Mats K. G.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Skrivfars, Mikael
    Plummer, Christopher
    Berglund, Lars A.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Biocomposites of nanofibrillated cellulose with thermoset resins2014Inngår i: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, s. 41-CELL-Artikkel i tidsskrift (Annet vitenskapelig)
  • 62. Ao, Xianyu
    et al.
    Wang, Xuyue
    Yin, Guanbo
    Dang, Kangkang
    Xue, Yali
    He, Sailing
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion. Zhejiang University, China.
    Broadband Metallic Absorber on a Non-Planar Substrate2015Inngår i: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 11, nr 13, s. 1526-1530Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Absorbers for visible and near-infrared light are realized by depositing a thin iron layer on arrays of cones which are replicated from a porous template. The replicated conic structure itself is of several micrometers and ineffective at antireflection, but the subsequent deposition of iron on top generates nanometer-size columnar structures, and thus broadband absorption enhancement is achieved.

  • 63.
    Apaydin, Dogukan H.
    et al.
    Johannes Kepler University of Linz, Austria.
    Gora, Monika
    University of Warsaw, Poland.
    Portenkirchner, Engelbert
    University of Innsbruck, Austria.
    Oppelt, Kerstin T.
    Johannes Kepler University of Linz, Austria.
    Neugebauer, Helmut
    Johannes Kepler University of Linz, Austria.
    Jakesoya, Marie
    Johannes Kepler University of Linz, Austria.
    Glowacki, Eric D.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Kunze-Liebhaeuser, Julia
    University of Innsbruck, Austria.
    Zagorska, Malgorzata
    Warsaw University of Technology, Poland.
    Mieczkowski, Jozef
    University of Warsaw, Poland.
    Serdar Sariciftci, Niyazi
    Johannes Kepler University of Linz, Austria.
    Electrochemical Capture and Release of CO2 in Aqueous Electrolytes Using an Organic Semiconductor Electrode2017Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, nr 15, s. 12919-12923Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Developing efficient methods for capture and controlled release of carbon dioxide is crucial to any carbon. capture and utilization technology. Herein we present an approach using an organic. semiconductor electrode to electrochemically capture dissolved CO2 in aqueous electrolytes. The process relies on electrochemical reduction of a thin film of a naphthalene bisimide derivative, 2,7,bis (4-(2- (2-ethylhexyl)thiazol-4-yl)phenyObenzo [lmn][3,8] phenanthroline-1,3,6,8(2H,7H)-tetraone (NBIT). This molecule is specifically tailored to afford one-electron reversible and one-electron quasi-reversible reduction in aqueous conditions while, not dissolving or degrading. The reduced NBIT reacts with CO2 to form a stable aemicarbonate salt, which can be subsequently oxidized electrochemically to release CO2. The semicarbonate structure is confirmed by in situ IR spectroelectrochemistry. This process of capturing and releasing carbon dioxide can be realized in an oxygen-free environment under ambient pressure and temperature, with uptake efficiency for CO2 capture of similar to 2.3 mmol g(-1). This is on par with the best solution-phase amine chemical capture technologies available today.

  • 64. Arabasadi, Z.
    et al.
    Khorasani, M.
    Akhlaghi, Shahin
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Fazilat, H.
    Gedde, Ulf W.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymera material.
    Hedenqvist, Mikael S.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Polymera material.
    Shiri, M. E.
    Prediction and optimization of fireproofing properties of intumescent flame retardant coatings using artificial intelligence techniques2013Inngår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 61, s. 193-199Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A multi-structured architecture of artificial intelligence techniques including artificial neural network (ANN), adaptive neuro-fuzzy-inference-system (ANFIS) and genetic algorithm (GA) were developed to predict and optimize the fireproofing properties of a model intumescent flame retardant coating including ammonium polyphosphate, pentaerythritol, melamine, thermoplastic acrylic resin and liquid hydrocarbon resin. By implementing ANN on heat insulation results of coating samples, prepared based on a L16 orthogonal array, mean fireproofing time (MFPT) values were properly predicted. The predicted data were then proved to be valid through performing closeness examinations on fuzzy inference systems results regarding their experimental counterparts. However, the possible deviations tapped into phenomena like foam detachment and char cracking were alleviated by ANFIS modeling embedded with pertinent fuzzy rules based on the sole and associative practical role of used additives. The contribution of each intumescent coating component on the formulation with optimized fireproofing behavior was then explored using GA modeling. A similar optimization procedure was also conducted using conventional Taguchi experimental design but the GA based optimized intumescent coating was found to exhibit higher MFPT value than that suggested by the Taguchi method.

  • 65.
    Araujo, Rafael B.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap, Fasta tillståndets fysik.
    Bayrak Pehlivan, Ilknur
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap, Fasta tillståndets fysik.
    Edvinsson, Tomas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för materialvetenskap, Fasta tillståndets fysik.
    High-entropy alloy catalysts: Fundamental aspects, promises towards electrochemical NH3 production, and lessons to learn from deep neural networks2023Inngår i: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 105, artikkel-id 108027Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A computational approach to judiciously predict high-entropy alloys (HEAs) as an efficient and sustainable material class for the electrochemical reduction of nitrogen is here presented. The approach employs density functional theory (DFT), adsorption energies of N atoms and N2 molecules as descriptors of the catalytic activity and deep neural networks. A probabilistic approach to quantifying the activity of HEA catalysts for nitrogen reduction reaction (NRR) is described, where catalyst elements and concentration are optimized to increase the probability of specific atomic arrangements on the surfaces. The approach provides key features for the effective filtering of HEA candidates without the need for time-consuming calculations. The relationships between activity and selectivity, which correlate with the averaged valence electron concentration and averaged electronegativity of the reference HEA catalyst, are analyzed in terms of sufficient interaction for sustained reactions and, at the same time, for the release of the active site. As a result, a complete list of 3000 HEAs consisting of quinary components of the elements Mo, Cr, Mn, Fe, Co, Ni, Cu, and Zn are reported together with their metrics to rank them from the most likely to the least likely active catalysts for NRR in gas diffusion electrodes, or for the case where non-aqueous electrolytes are utilized to suppress the competing hydrogen evolution reaction. Moreover, the energetic landscape of the electrochemical NRR transformations are computed and compared to the case of Fe. The study also analyses and discusses how the results would translate to liquid-solid reactions in aqueous electrochemical cells, further affected by changes in properties upon hydroxylation, oxygen, hydrogen, and water coverages.

    Fulltekst (pdf)
    fulltext
  • 66.
    Arja, Katriann
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Selegård, Robert
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biofysik och bioteknik. Linköpings universitet, Tekniska fakulteten.
    Paloncyova, Marketa
    KTH Royal Inst Technol, Sweden; Palacky Univ Olomouc, Czech Republic.
    Linares, Mathieu
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Lindgren, Mikael
    Norwegian Univ Sci & Technol, Norway.
    Norman, Patrick
    KTH Royal Inst Technol, Sweden.
    Aili, Daniel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biofysik och bioteknik. Linköpings universitet, Tekniska fakulteten.
    Nilsson, Peter
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Kemi. Linköpings universitet, Tekniska fakulteten.
    Self-Assembly of Chiro-Optical Materials from Nonchiral Oligothiophene-Porphyrin Derivatives and Random Coil Synthetic Peptides2023Inngår i: ChemPlusChem, E-ISSN 2192-6506, Vol. 88, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Biomimetic chiral optoelectronic materials can be utilized in electronic devices, biosensors and artificial enzymes. Herein, this work reports the chiro-optical properties and architectural arrangement of optoelectronic materials generated from self-assembly of initially nonchiral oligothiophene-porphyrin derivatives and random coil synthetic peptides. The photo-physical- and structural properties of the materials were assessed by absorption-, fluorescence- and circular dichroism spectroscopy, as well as dynamic light scattering, scanning electron microscopy and theoretical calculations. The materials display a three-dimensional ordered helical structure and optical activity that are observed due to an induced chirality of the optoelectronic element upon interaction with the peptide. Both these properties are influenced by the chemical composition of the oligothiophene-porphyrin derivative, as well as the peptide sequence. We foresee that our findings will aid in developing self-assembled optoelectronic materials with dynamic architectonical accuracies, as well as offer the possibility to generate the next generation of materials for a variety of bioelectronic applications.

    Fulltekst (pdf)
    fulltext
  • 67.
    Arjmand, Mehdi
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Moreno, Luis
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Liu, Longcheng
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Energy Saving in Crude Oil Atmospheric Distillation Columns by Modifying the Vapor Feed Inlet Tray2011Inngår i: Chemical Engineering & Technology, ISSN 0930-7516, E-ISSN 1521-4125, Vol. 34, nr 8, s. 1359-1367Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Optimization of a typical crude oil atmospheric distillation unit and reduction of energy conservation were carried out through modifying the implementation and change in the flash zone of the tower. A conventional procedure in such units involves the combination of liquid and vapor product of the prefractionation train surge drum upon introduction to the tower. However, it is theoretically illustrated and represented by simulation means that introducing the vapor feed into the upper stages of the distillation column separately can lead to an energy saving of 12.6% in the condenser duty, an increased liquid-to-gas flow (L/G) at certain points of the column, and hence to a reduction in diameter and investment costs of new tower designs of approximately US$ 0.7 million a(-1). The proposal can be put into practice without the need of additional equipments or additional cost of difficult rerouting the streams. An industrial case study of a steadystate crude oil distillation unit is given by simulation provision of AspenHysys (TM).

  • 68.
    Arjmand, Mehdi
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Moreno, Luis
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Liu, Longcheng
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Optimization for energy conservation of crude oil atmospheric distillation columns by modifying vapour feed inlet tray from pre-fractionation train2010Inngår i: 2010 AIChE Annual Meeting, 2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Optimization of a typical crude oil atmospheric distillation unit and reduction of energy conservation were carried out through modifying the implementation and change in the flash zone of the tower. Conventional procedure in such units involves combination of liquid and vapour product of the pre-fractionation train surge drum upon insertion to the tower. However it is theoretically illustrated and represented by simulation means that introducing the vapour feed into the upper stages of the distillation column separately can lead to an energy saving of 12.6% in the condenser duty, increased liquid to gas flow (L/G) at certain points of the column and hence a reduction in diameter and investment costs of new tower designs of approximately 0.7 × 10 6 $/y. The proposal can be put into practice without the need of additional equipments or additional cost of difficult re-routing the streams. An industrial case study of a steady-state crude oil distillation unit is given by simulation provision of AspenHysys™.

  • 69.
    Aro, Rudolf
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Organofluorine Mass Balance and Per- and Polyfluoroalkyl Substance Analysis of Environmental Samples and Human Blood2021Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Per- and polyfluoroalkyl substances (PFAS) have been linked to a range of negative health and environmental effects. Regulations limiting and/or banning the use of some of the legacy compounds have been introduced. Consequently, the production and use of PFAS has diversified. The risks posed by these newly introduced PFAS to both the environment and humans may be underestimated if they are not evaluated in current monitoring programs. Organofluorine mass balance analysis has been used in previous studies to estimate the overall exposure to PFAS since naturally occurring organofluorine compounds are rare in nature.

    In this thesis, the organofluorine mass balance analysis was performed on a variety of samples, from surface water to sewage and human blood. The results indicated the ubiquitous presence of unidentified organofluorines in all environmental compartments and human samples, for example, more than 50 % of extractable organofluorine (EOF) in human samples could not be accounted for by an extended list of target analytes. Until these compounds are identified, it is not possible to assess the risks they pose and it could lead to misguided policy decisions.

    To tackle the increasingly complex analytical picture and ensure more comprehensive screening, a workflow using EOF as an initial metric to identify pollution hot-spots was proposed. The wider adoption of organofluorine mass balance analysis would also require a better understanding of the analytical instrumentation used for this type of work. Experiments carried out here demonstrated the robustness of combustion ion chromatography in EOF analysis and highlighted areas in need of improvement.

    While organofluorine mass balance analysis has its drawbacks, the potential health and environmental risks posed by the unidentified organofluorine compounds cannot be underestimated.

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    Organofluorine Mass Balance and Per- and Polyfluoroalkyl Substance Analysis of Environmental Samples and Human Blood
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  • 70.
    Aro, Rudolf
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Eriksson, Ulrika
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kärrman, Anna
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Jakobsson, Kristina
    School of Public Health and Community Medicine, Institute of Medicine, University of Gothenburg, Gothenburg, Sweden.
    Yeung, Leo W. Y.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Extractable Organofluorine Analysis: a Way to Screen for Elevated Per- and Polyfluoroalkyl Substance Contamination in Humans?Manuskript (preprint) (Annet vitenskapelig)
  • 71.
    Aro, Rudolf
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Eriksson, Ulrika
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kärrman, Anna
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Reber, Iris
    Metrohm AG, Ionenstrasse, Herisau, Switzerland.
    Yeung, Leo W. Y.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Combustion Ion Chromatography for Extractable Organofluorine AnalysisManuskript (preprint) (Annet vitenskapelig)
  • 72.
    Aro, Rudolf
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Eriksson, Ulrika
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Kärrman, Anna
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Yeung, Leo W. Y.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Organofluorine Mass Balance Analysis of Whole Blood Samples in Relation to Gender and AgeManuskript (preprint) (Annet vitenskapelig)
  • 73. Artemenko, A.
    et al.
    Shchukarev, Andrey
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Štenclová, P.
    Wågberg, Thomas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Segervald, Jonas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Jia, X.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Kromka, A.
    Reference XPS spectra of amino acids2021Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this report we present XPS data for five amino acids (AAs) (tryptophan, methionine, glutamine, glutamic acid, and arginine) with different side chain groups measured in solid state (powder form). The theoretically and experimentally obtained chemical structure of AAs are compared. Here, we analyse and discuss C 1 s, N 1 s, O 1s and S 2p core level binding energies, FWHMs, atomic concentrations of the functional groups in AAs. The experimentally obtained and theoretically calculated ratio of atomic concentrations are compared. The zwitterionic nature of methionine and glutamine in solid state was determined from protonated amino groups in N 1s peak and deprotonated carboxylic groups in the C 1s spectrum. The obtained XPS results for AAs well correspond with previously reported data.

    Fulltekst (pdf)
    fulltext
  • 74.
    Arvidsson, Martin
    et al.
    Department of Psychology, Stockholm University.
    Skedung, Lisa
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Aikala, Maiju
    Oy Keskuslaboratorio - Centrallaboratorium Ab.
    Danerlöv, Katrin
    YKI Institute for Surface Chemistry.
    Kettle, John
    Oy Keskuslaboratorio - Centrallaboratorium Ab.
    Rutland, Mark
    KTH, Skolan för kemivetenskap (CHE), Kemi, Yt- och korrosionsvetenskap.
    Berglund, Birgitta
    Department of Psychology, Stockholm University.
    Haptic perception of fine surface texture: Psychophysical interpretation of the multidimensional spaceManuskript (preprint) (Annet vitenskapelig)
  • 75.
    Asem, Heba
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Malmström, Eva
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Polymeric Nanoparticles Explored for Drug-Delivery Applications2018Inngår i: Gels and Other Soft Amorphous Solids, American Chemical Society (ACS), 2018, s. 315-331Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The main drawback of conventional chemotherapeutics is their non-specific distribution in the body which causes serious side effects to healthy cells. As a consequence, the drug concentration reaching the tumor is reduced, resulting in suboptimal therapeutic efficacy. The discovery that polymer-based nanomaterials can be used for controlled drug delivery systems offers well-defined reservoirs for a wide spectrum of pharmaceutical agents, with the ability to reduce the toxic response. The most widely explored polymeric nanocarriers, including biodegradable polymers, amphiphilic copolymers and polymers that form unimolecular micelles, are discussed in this brief chapter.

  • 76.
    Asiimwe, Savina
    et al.
    Makerere Univ, Sch Biosci, Kampala, Uganda.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Azeem, Muhammad
    Mugisha, Maud Kamatenesi
    Namutebi, Agnes
    Gakunga, Ndukui James
    Chemical composition and Toxicological evaluation of the aqueous leaf extracts of Plectranthus amboinicus Lour: Spreng2014Inngår i: International Journal of Pharmaceutical Science Invention, ISSN 2319-6718, Vol. 3, nr 2, s. 19-27Artikkel i tidsskrift (Fagfellevurdert)
  • 77.
    Asiimwe, Savina
    et al.
    Makerere Univ, Sch Biosci, Kampala, Uganda.
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Azeem, Muhammad
    Sofrata, Abier Hamed
    Byamukama, Robert
    Mugisha, Maud Kamatenesi
    Namutebi, Agnes
    Chemical composition and antimicrobial evaluation of the essential oil and fractions obtained from Plectranthus amboinicus(Lour.): Spreng traditionally used in the management of HIV/AIDS opportunistic infectionsManuskript (preprint) (Annet vitenskapelig)
  • 78.
    Asiimwe, Savina
    et al.
    Makerere Univ, Sch Biosci, Kampala, Uganda.
    Namutebi, Agnes
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Mugisha, Maud Kamatenesi
    Kakudidi, Esezah Kyomugisha
    Hannington, Ortem-Origa
    Documentation and consensus of indigenous knowledge on medicinal plants used by the local communities of western Uganda2014Inngår i: Journal of Natural Product and Plant Resource, ISSN 2231-3184, Vol. 4, nr 1, s. 34-42Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An ethnobotanical study was conducted to document the uses of medicinal plants among the local communities of western Uganda. The aim of the study was to identify and document plant species used for treatment of various ailments in the study areas, identify the commonly used plants, parts used, preparation and administration of herbal drugs. To find out the level of consensus or agreement between informants regarding the uses of plants for particular disease categories. Information on the plants was gathered between December 2010 and May 2011 from 124 informants using semi-structured interviews and discussions. For analysis of general use of plants, factor informant consensus (Fic) was used. The reported plants were collected and identified. The study revealed 231plant species belonging to 72 families and 164 genera. These plants were used to treat various diseases and ailments grouped under 14 ailment categories, with the highest number of species (127) being used for gastrointestinal disorders followed by reproductive health disorders (75). The factor informant consensus highlighted low agreement in the use of plants. The highest Fic (0.61) was scored for the digestive problems, such as intestinal worms, stomachache and constipation. Aloe vera was used for malaria with the highest frequency of mention (26 mentions). Herbs (55%) were the main source of medicine followed by shrubs (18%). Leaves (65%) and roots (19%) were the main plant parts used in remedy preparation while decoction was the major form of preparation. Family Asteraceae accounted for 16% of the total species recorded. The majority of plants (53%) were harvested from wild habitats. The most important species according to their fidelity are Senna occidentalis (L.) Link for deworming, Aloe vera L. for malaria, Maytenus senegalensis (Lam) Exell for syphilis and Senecio hadiensis Forssk for miscarriages.The low consensus means the majority of informants do not agree or exchange information on the use of plant species and this may require bioactivity screening to justify the use for the reported ailments. The documented information regarding therapeutic uses provides basic data for further studies focused on pharmacological studies and conservation of the most important species.

  • 79.
    Asiimwe, Savina
    et al.
    Makerere Univ, Sch Biosci, Kampala, Uganda.
    Namutebi, Agnes
    Mugisha, Maud Kamatenesi
    Borg-Karlson, Anna-Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Phytochemical screening, antioxidant activities and mineral composition of nutri-medicinal plants used in the management of opportunistic ailments in HIV/AIDS patientsManuskript (preprint) (Annet vitenskapelig)
  • 80. Assali, S.
    et al.
    Laehnemann, J.
    Vu, T. T. T.
    Jöns, Klaus
    Delft University of Technology, Netherlands.
    Gagliano, L.
    Verheijen, M. A.
    Akopian, N.
    Bakkers, E. P. A. M.
    Haverkort, J. E. M.
    Crystal Phase Quantum Well Emission with Digital Control2017Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 17, nr 10, s. 6062-6068Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One of the major challenges in the growth of quantum well and quantum dot heterostructures is the realization of atomically sharp interfaces. Nanowires provide a new opportunity to engineer the band structure as they facilitate the controlled switching of the crystal structure between the zinc-blende (ZB) and wurtzite (WZ) phases. Such a crystal phase switching results in the formation of crystal phase quantum wells (CPQWs) and quantum dots (CPQDs). For GaP CPQWs, the inherent electric fields due to the discontinuity of the spontaneous polarization at the WZ/ZB junctions lead to the confinement of both types of charge carriers at the opposite interfaces of the WZ/ZB/WZ structure. This confinement leads to a novel type of transition across a ZB flat plate barrier. Here, we show digital tuning of the visible emission of WZ/ZB/WZ CPQWs in a GaP nanowire by changing the thickness of the ZB barrier. The energy spacing between the sharp emission lines is uniform and is defined by the addition of single ZB monolayers. The controlled growth of identical quantum wells with atomically flat interfaces at predefined positions featuring digitally tunable discrete emission energies may provide a new route to further advance entangled photons in solid state quantum systems.

  • 81.
    Assefa, Anteneh
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Tysklind, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Bignert, Anders
    Josefsson, Sarah
    Wiberg, Karin
    Sources of polychlorinated dibenzo-p-dioxins and dibenzofurans to Baltic Sea herring2019Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 218, s. 493-500Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in herring (Clupea harengus) remain high in several parts of the Baltic Sea, despite declines in PCDD/F emissions since the 1980s. The reasons behind this are not well understood. This study applied a statistical modeling approach where sources of PCDD/Fs that contaminate Baltic biota were quantitatively assessed by analyzing existing datasets. PCDD/F patterns were extracted from a herring dataset using positive matrix factorization (PMF). The extracted biota patterns were transformed into sediment patterns using fish-to-sediment transformation factors, and the resulting patterns were compared with known source PCDD/F patterns. The model distinguished three model patterns, which explained 85% of the data. These patterns were matched to tetra-chlorophenol (TCP), penta-chlorophenol/atmospheric background (PCP/AB), and thermal source patterns, respectively. The thermal source was the largest contributor to toxic equivalents (TEQ) in herring, but the level decreased from 42 ± 9.0 pg TEQ g−1 lipid weight (lw) before year 2000 (pre-2000) to 15 ± 2.4 pg TEQ g−1 lw post-2000, i.e., a decline of around one-third in the original TEQ concentration. The contribution of TCP more than doubled, from 2.1 ± 0.62 pg TEQ g−1 lw to 5.6 ± 1.1 pg TEQ g−1 lw, and the relative contribution of PCP/AB also increased. These increasing trends suggest that, as primary air emissions of PCDD/Fs are managed and levels decline, the impact of TCP and PCP/AB sources on Baltic Sea biota will become more important over time and that PCDD/F-contaminated sites in coastal areas and marine environments require more attention.

  • 82.
    ASTORSDOTTER, JENNIFER
    et al.
    KTH, Skolan för kemivetenskap (CHE).
    RICKNELL, JONAS
    KTH, Skolan för kemivetenskap (CHE).
    YU, FIONA
    KTH, Skolan för kemivetenskap (CHE).
    Forsgren, Axel
    KTH, Skolan för kemivetenskap (CHE).
    Utformning av avgaskatalysator2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Naturgas är ett alternativ till oljebaserade bränslen. Ur ett miljöperspektiv är naturgasen fördelaktig eftersom den vid förbränning ger mindre utsläpp av miljöfarliga ämnen än olja. I en diesel dual-fuel motor används diesel och naturgas som bränsle. Naturgas består till största delen av metan. För att oskadliggöra den del av metangasen som inte förbränns i motorn krävs en avgaskatalysator som kan bryta ned det relativt stabila metanet vid låga temperaturer. Målet med det här kandidatexamensarbetet är att tillverka och testa tre olika avgaskatalysatorer för nedbrytning av metan. De tre katalysatorer som valdes för tillverkning och testning var Pd/Al2O3, Pd/SnO2 och In2O3/SnO2 (ITO). Valen baserade sig på att katalysatorerna som tillverkades skulle vara aktiva för nedbrytning av metan vid låga temperaturer. ITO sågs som en extra intressant kandidat eftersom In är billigare än ädelmetallen Pd. Pd/Al2O3 tillverkades med en kommersiell support och impregnering av Pd genom ”incipient wetness” (IW). Pd/SnO2 tillverkades på samma sätt. ITO tillverkades genom ”forward co-precipitation”. En monolit testades för varje katalysator. Vid ungefär 315 °C kunde 10 % omsättning av metan detekteras för alla tre katalysatorer. Pd/Al2O3 var den katalysator vars aktivitet förbättrades som mest då temperaturen ökade ytterligare. Katalysatorerna testades bara en gång. För att statistiskt säkerställa resultaten behöver upprepade tester göras. Resultaten överensstämmer delvis med tidigare studier. Slutsatsen av arbetet är att alla tre katalysatorer fungerar och att ITO skulle kunna vara en billigare men i övrigt likvärdig avgaskatalysator för en diesel dual-fuel lean burn motor vid 315 °C. Fler tester måste dock göras för att ta reda på om ITO verkligen är ett mer fördelaktigt alternativ. 

    Fulltekst (pdf)
    fulltext
  • 83.
    Aulin, Christian
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Karabulut, Erdem
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Tran, Amy
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Wågberg, Lars
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lindström, Tom
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Transparent Nanocellulosic Multilayer Thin Films on Polylactic Acid with Tunable Gas Barrier Properties2013Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 5, nr 15, s. 7352-7359Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The layer-by-layer (LbL) deposition method was used for the build-up of alternating layers of nanofibrillated cellulose (NFC) or carboxymethyl cellulose (CMC) with a branched, cationic polyelectrolyte, polyethyleneimine (PEI) on flexible poly (lactic acid) (PLA) substrates. With this procedure, optically transparent nanocellulosic films with tunable gas barrier properties were formed. 50 layer pairs of PEI/NFC and PEI/CMC deposited on PLA have oxygen permeabilities of 0.34 and 0.71 cm(3).mu m/m(2).day.kPa at 23 degrees C and 50% relative humidity, respectively, which is in the same range as polyvinyl alcohol and ethylene vinyl alcohol. The oxygen permeability of these multilayer nanocomposites outperforms those of pure NFC films prepared by solvent-casting. The nanocellulosic LbL assemblies on PLA substrates was in detailed characterized using a quartz crystal microbalance with dissipation (QCM-D). Atomic force microscopy (AFM) reveals large structural differences between the PEI/NFC and the PEI/CMC assemblies, with the PEI/NFC assembly showing a highly entangled network of nanofibrils, whereas the PEI/CMC surfaces lacked structural features. Scanning electron microscopy images showed a nearly perfect uniformity of the nanocellulosic coatings on PLA, and light transmittance results revealed remarkable transparency of the LbL-coated PLA films. The present work demonstrates the first ever LbL films based on high aspect ratio, water-dispersible nanofibrillated cellulose, and water-soluble carboxymethyl cellulose polymers that can be used as multifunctional films and coatings with tailorable properties, such as gas barriers and transparency. Owing to its flexibility, transparency and high-performance gas barrier properties, these thin film assemblies are promising candidates for several large-scale applications, including flexible electronics and renewable packaging.

  • 84.
    Aulin, Christian
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi.
    Salazar-Alvarez, German
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Lindström, Tom
    KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    High strength, flexible and transparent nanofibrillated cellulose-nanoclay biohybrid films with tunable oxygen and water vapor permeability2012Inngår i: Nanoscale, ISSN 2040-3364, Vol. 4, nr 20, s. 6622-6628Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel, technically and economically benign procedure to combine vermiculite nanoplatelets with nanocellulose fibre dispersions into functional biohybrid films is presented. Nanocellulose fibres of 20 nm diameters and several micrometers in length are mixed with high aspect ratio exfoliated vermiculite nanoplatelets through high-pressure homogenization. The resulting hybrid films obtained after solvent evaporation are stiff (tensile modulus of 17.3 GPa), strong (strength up to 257 MPa), and transparent. Scanning electron microscopy (SEM) shows that the hybrid films consist of stratified nacre-like layers with a homogenous distribution of nanoplatelets within the nanocellulose matrix. The oxygen barrier properties of the biohybrid films outperform commercial packaging materials and pure nanocellulose films showing an oxygen permeability of 0.07 cm(3) mu m m(-2) d(-1) kPa(-1) at 50% relative humidity. The oxygen permeability of the hybrid films can be tuned by adjusting the composition of the films. Furthermore, the water vapor barrier properties of the biohybrid films were also significantly improved by the addition of nanoclay. The unique combination of excellent oxygen barrier behavior and optical transparency suggests the potential of these biohybrid materials as an alternative in flexible packaging of oxygen sensitive devices such as thin-film transistors or organic light-emitting diode displays, gas storage applications and as barrier coatings/laminations in large volume packaging applications.

  • 85. Aulin, Christian
    et al.
    Shchukarev, Andrey
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Lindqvist, Josefina
    Malmström, Eva
    Wågberg, Lars
    Lindström, Tom
    Wetting kinetics of oil mixtures on fluorinated model cellulose surfaces2008Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 317, nr 2, s. 556-67Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The wetting of two different model cellulose surfaces has been studied; a regenerated cellulose (RG) surface prepared by spin-coating, and a novel multilayer film of poly(ethyleneimine) and a carboxymethylated microfibrillated cellulose (MFC). The cellulose films were characterized in detail using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM indicates smooth and continuous films on a nanometer scale and the RMS roughness of the RG cellulose and MFC surfaces was determined to be 3 and 6 nm, respectively. The cellulose films were modified by coating with various amounts of an anionic fluorosurfactant, perfluorooctadecanoic acid, or covalently modified with pentadecafluorooctanyl chloride. The fluorinated cellulose films were used to follow the spreading mechanisms of three different oil mixtures. The viscosity and surface tension of the oils were found to be essential parameters governing the spreading kinetics on these surfaces. XPS and dispersive surface energy measurements were made on the cellulose films coated with perfluorooctadecanoic acid. A strong correlation was found between the surface concentration of fluorine, the dispersive surface energy and the contact angle of castor oil on the surface. A dispersive surface energy less than 18 mN/m was required in order for the cellulose surface to be non-wetting (θe>90°) by castor oil.

    Graphical abstract

    AFM tapping mode image of a bilayer of PEI/MFC on silica in the height mode. The scanned surface area was 1 μm2 (left) and dispersive surface energy of fluorinated regenerated cellulose surfaces vs atomic fluorine concentration (right).

  • 86.
    Aulin, Christian
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Ström, Göran
    Multilayered Alkyd Resin/Nanocellulose Coatings for Use in Renewable Packaging Solutions with a High Level of Moisture Resistance2013Inngår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 52, nr 7, s. 2582-2589Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A surprisingly simple and rapid methodology for large-area, lightweight, and thin laminate coatings with remarkable moisture barrier properties is introduced. Commercially available paperboards are coated with thin layers of nanocellulose. The nanocellulose coating induces a surface smoothening effect on the coated sheets as characterized by environmental scanning electron microscopy and white light interferometry. A moisture-protective layer of renewable alkyd resins is deposited on the nanocellulose precoated sheets using a water-borne dispersion coating process or lithographic printing. Through an auto-oxidation process, the applied alkyd resins are transformed into moisture sealant layers. The moisture barrier properties are characterized in detail by water vapor permeability measurements at different levels of relative humidity. The water vapor barrier properties of the nanocellulose precoated substrates were significantly improved by thin layers of renewable alkyd resins. The effect of the alkyd resin properties, coating technologies, and base paper substrates on the final barrier performance of the sheets were studied. It was found that the nanocellulose coating had a notable effect on the homogeneity and barrier performance of the alkyd resin layers and in particular those alkyd resin layers that were applied by printing. The concept is environmentally friendly, energy-efficient, and economic and is ready for scaling-up via continuous roll-to-roll processes. Large-scale renewable coatings applicable for sustainable packaging solutions are foreseen.

  • 87.
    Azeem, Muhammad
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Borg-Karlson, Anna Karin
    KTH, Skolan för kemivetenskap (CHE), Kemi, Organisk kemi.
    Kuttuva Rajarao, Gunaratna
    KTH, Skolan för bioteknologi (BIO), Industriell bioteknologi.
    Sustainable bio-production of styrene from forest waste2013Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 144, s. 684-688Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A strain of Penicillium expansum was studied for the production of styrene using forest waste biomass as a feeding substrate. The fungal strain was cultivated on bark of various trees supplemented with yeast extract and the volatiles produced were collected on Tenax TA and analyzed by gas chromatography-mass spectrometry. Fungus cultured on grated soft bark of pine (Pinus sylvestris) stems (GPB) and mature bark of oak (Quercus robur) supplemented with yeast extract produced relatively the highest amounts of styrene. The maximum styrene production rate was 52.5 mu g/h, 41 mu g/h and 27 mu g/h from fungus cultivated on 50 mL liquid media with 10 g GPB or mature bark of oak and potato dextrose broth respectively. These promising results suggest that the fungal strain could be used to produce "green" styrene plastics using renewable forest waste biomass.

  • 88.
    Azharuddin, Mohammad
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för klinisk kemi. Linköpings universitet, Medicinska fakulteten.
    Zhu, Geyunjian H.
    Univ Cambridge, England.
    Das, Debapratim
    Indian Inst Technol Guwahati, India.
    Ozgur, Erdogan
    Hacettepe Univ, Turkey.
    Uzun, Lokman
    Hacettepe Univ, Turkey.
    Turner, Anthony P. F.
    Cranfield Univ, England.
    Patra, Hirak Kumar
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för cellbiologi. Linköpings universitet, Medicinska fakulteten. Univ Cambridge, England.
    A repertoire of biomedical applications of noble metal nanoparticles2019Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 55, nr 49, s. 6964-6996Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Noble metals comprise any of several metallic chemical elements that are outstandingly resistant to corrosion and oxidation, even at elevated temperatures. This group is not strictly defined, but the tentative list includes ruthenium, rhodium, palladium, silver, osmium, iridium, platinum and gold, in order of atomic number. The emerging properties of noble metal nanoparticles are attracting huge interest from the translational scientific community and have led to an unprecedented expansion of research and exploration of applications in biotechnology and biomedicine. Noble metal nanomaterials can be synthesised both by top-down and bottom up approaches, as well as via organism-assisted routes, and subsequently modified appropriately for the field of use. Nanoscale analogues of gold, silver, platinum, and palladium in particular, have gained primary importance owing to their excellent intrinsic properties and diversity of applications; they offer unique functional attributes, which are quite unlike the bulk material. Modulation of noble metal nanoparticles in terms of size, shape and surface functionalisation has endowed them with unusual capabilities and manipulation at the chemical level, which can lead to changes in their electrical, chemical, optical, spectral and other intrinsic properties. Such flexibility in multi-functionalisation delivers Ockhams razor to applied biomedical science. In this feature article, we highlight recent advances in the adaptation of noble metal nanomaterials and their biomedical applications in therapeutics, diagnostics and sensing.

    Fulltekst (pdf)
    fulltext
  • 89.
    Babu, Aishwarya
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik.
    Effect of various rate promoters on the absorption rate of carbon dioxide in potassium carbonate solvents2022Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Det ständigt växande behovet av att minska CO2-utsläpp har lett till en ökad tonvikt på teknik för avskiljning av koldioxid från rökgas. MEA (monoetanolamin) anses vara riktmärket för lösningsmedel för att fånga in koldioxid på grund av dess höga absorptionshastighet. MEA är dock benäget att brytas ner, bilda giftiga biprodukter och dess regenerering har ett högt energibehov. Ett annat lösningsmedel med liknande teknisk mognad är vattenlösning med kaliumkarbonat (K2CO3) som används i den så kallade hot-potash carbonate (HPC)-processen. Emellertid är absorptionshastigheten i K2CO3-lösningen låg i jämförelse med MEA, vilket kräver tillsats av hastighetspromotorer för att öka absorptionshastigheten.

    Denna avhandling undersöker effekten av olika hastighetspromotorer på absorptionshastigheten av kaliumkarbonat. För detta utfördes absorptionsexperiment i laboratorieskala i en autoklavreaktor av rostfritt stål under kontrollerade förhållanden. Olika promotorer har undersökts, nämligen de organiska promotorerna glycin, piperazin och MEA, och de oorganiska promotorerna borsyra och vanadinpentoxid. Promotorkoncentrationen varierades mellan 3 vikt% till 7 vikt% samtidigt som koncentrationen av K2CO3 hölls konstant vid 25 vikt%. Driftförhållandena såsom det initiala partialtrycket av CO2 och temperaturen var respektiva 5 bar och 50 °C. De oorganiska promotorerna studerades enskilt såväl som i blandningar med K2CO3 för att studera effekten av varje promotor.

    De organiska promotorerna visade en signifikant förbättring av absorptionshastigheten jämfört med icke promoterad K2CO3. När det gäller de oorganiska promotorerna visade vanadinpentoxid jämförbara resultat med organiska promotorer med endast 3 vikt%. Ökad tillsatts av borsyra minskade absorptionshastigheten av lösningen promoterad av vanadin. Den experimentellt uppmätta absorptionshastigheten är anpassad till en enkel absorptionsmodell från vilken en skenbar absorptionshastighet för de främjade lösningsmedlen härleddes

    Fulltekst (pdf)
    fulltext
  • 90.
    Backlund, Anders
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för läkemedelskemi, Avdelningen för farmakognosi.
    Topical chemical space in relation to biological space2010Inngår i: Comprehensive Natural Products II: Chemistry and Biology / Volume 3 / [ed] L. Mander & H.-W. Lui, Oxford: Elsevier, 2010, s. 47-79Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    In this chapter, the mapping of physical–chemical descriptor space of natural products and its relation to the biological space, with emphasis on evolutionary and topical biological space, is discussed. A brief presentation of methods for phylogenetic analysis and their different advantages is followed by discussions of evolutionary implications. Examples from both unpublished and previously published studies are presented.

  • 91.
    Badea, Silviu-Laurentiu
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Association of hydrophobic organic compounds to organic material in the soil system2013Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Contaminated soils and sediments have been identified as significant secondary sources of organic contaminants.  Leaching tests may be useful tools to estimate the mobility of contaminants via the water phase and thereby the risk for groundwater and surface water contamination. The influence of soil composition (peat and clay content) on the leachability was investigated in batch leaching experiments for chemically diverse hydrophobic organic compounds (HOCs: PCP, PAHs, HCB, HCHs, PCBs, and TCDD/Fs). The above mentioned compounds were analyzed by both GC-LRMS (gas chromatography coupled with low resolution mass spectrometry (GC-HRMS) and GC-HRMS (gas chromatography coupled with high resolution mass spectrometry). Also the the leachability of eleven selected PCBs from naturally aged soil (Västervik, Sweden) was investigated in relation to the composition and concentration of dissolved organic matter at different pH (2 to 9), using a pH static test with initial acid/base addition. The the composition and of dissolved organic matter (DOM) at different pH values was explored by FTIR spectroscopy. The results were evaluated by orthogonal projections to latent structures (OPLS).

    Generally, for all model compounds studies, the Kd-values showed a variability of 2-3 orders of magnitude depending on the matrix composition. The Kd-values of moderately hydrophobic compounds, (e.g. HCHs, PCP and Phe), were correlated mainly with the organic matter content of soil. For more hydrophobic compounds (e.g.BaA, HCB and PCB 47), the leachability decreased as the proportions of  OM and clay contents increased. The Kd-values of 1,3,6,8-TCDD and 1,3,6,8-TCDF were  positively correlated with peat content but negatively correlated with clay content, while for PCB 153 and PCB 155 the correlations were reversed. The log Kd-values of all target PCBs decreased with increased pH values and the log Kd-values were highly correlated with the concentration of total organic carbon (TOC) in the leachates. The FTIR analysis of DOM showed that the least chlorinated and hydrophobic PCB congeners (i.e. PCB 28) might be associated with the hydrophilic fraction (i.e. carboxylic groups) of DOM. Our study demonstrated how complex interaction between the organic matter, clay components, pH and DOC influences the leachability of HOCs in a compound-specific manner.

    Fulltekst (pdf)
    Association of hydrophobic organic compounds to organic material in the soil system
  • 92. Badri, Zahra
    et al.
    Pathak, Shubhrodeep
    Fliegl, Heike
    Rashidi-Ranjbar, Parviz
    Bast, Radovan
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Marek, Radek
    Foroutan-Nejad, Gina
    Ruud, Kenneth
    All-Metal Aromaticity: Revisiting the Ring Current Model among Transition Metal Clusters2013Inngår i: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 9, nr 11, s. 4789-4796Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present new insight into the nature of aromaticity in metal clusters. We give computational arguments in favor of using the ring-current model over local indices, such as nucleus independent chemical shifts, for the determination of the magnetic aromaticity. Two approaches for estimating magnetically induced ring currents are employed for this purpose, one based on the quantum theory of atoms in molecules (QTAIM) and the other where magnetically induced current densities (MICD) are explicitly calculated. We show that the two-zone aromaticity/antiaromaticity of a number of 3d metallic clusters (Sc-3(-), Cu-3(+), and Cu-4(2-)) can be explained using the QTAIM-based magnetizabilities. The reliability of the calculated atomic and bond magnetizabilities of the metallic clusters are verified by comparison with MICD computed at the multiconfiguration self-consistent field (MCSCF) and density functional levels of theory. Integrated MCSCF current strength susceptibilities as well as a visual analysis of the calculated current densities confirm the interpretations based on the QTAIM magnetizabilities. In view of the new findings, we suggest a simple explanation based on classical electromagnetic theory to explain the anomalous magnetic shielding in different transition metal clusters. Our results suggest that the nature of magnetic aromaticity/antiaromaticity in transition-metal clusters should be assessed more carefully based on global indices.

  • 93.
    Bahar, Babak
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Odnevall Wallinder, Inger
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Leygraf, Christofer
    KTH, Skolan för kemivetenskap (CHE), Kemi, Korrosionslära.
    Corrosion-induced copper release from rain gutters2008Inngår i: Metall (Berlin. 1947), ISSN 0026-0746, Vol. 62, nr 3, s. 129-135Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    While runoff rates from copper roofs have been extensively studied during the last years, corresponding studies from copper rain gutters have been missing. A laboratory investigation has been undertaken to examine the influence of important runoff water parameters on the copper runoff from rain gutters. At a given rainfall quantity, the release rate of copper increases with decreasing runoff water intensity and decreasing degree of gutter inclination, and with increasing runoff acidity and increasing Cu2+-ion concentration in the runoff water. A comparison of the predicted long-term copper release from the gutter-system compared to the roof on a real building suggests that less than 5% of the total copper runoff originates from the gutter. However, single rain events may result in higher release rates, especially during the initial rain portion.

  • 94.
    Bai, Sai
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten. Univ Oxford, England.
    Da, Peimei
    Univ Oxford, England.
    Li, Cheng
    Univ Bayreuth, Germany; Xiamen Univ, Peoples R China.
    Wang, Zhiping
    Univ Oxford, England.
    Yuan, Zhongcheng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Fu, Fan
    Empa-Swiss Federal Laboratories for Materials Science and Technology, Duebendorf, Switzerland.
    Kawecki, Maciej
    Empa, Switzerland; Univ Basel, Switzerland.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Sakai, Nobuya
    Univ Oxford, England.
    Wang, Jacob Tse-Wei
    CSIRO Energy, Australia.
    Huettner, Sven
    Univ Bayreuth, Germany.
    Buecheler, Stephan
    Empa Swiss Fed Labs Mat Sci and Technol, Switzerland.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten. Univ Oxford, England.
    Snaith, Henry J.
    Univ Oxford, England.
    Planar perovskite solar cells with long-term stability using ionic liquid additives2019Inngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 571, nr 7764, s. 245-250Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Solar cells based on metal halide perovskites are one of the most promising photovoltaic technologies(1-4). Over the past few years, the long-term operational stability of such devices has been greatly improved by tuning the composition of the perovskites(5-9), optimizing the interfaces within the device structures(10-13), and using new encapsulation techniques(14,15). However, further improvements are required in order to deliver a longer-lasting technology. Ion migration in the perovskite active layer-especially under illumination and heat-is arguably the most difficult aspect to mitigate(16-18). Here we incorporate ionic liquids into the perovskite film and thence into positive-intrinsic-negative photovoltaic devices, increasing the device efficiency and markedly improving the long-term device stability. Specifically, we observe a degradation in performance of only around five per cent for the most stable encapsulated device under continuous simulated full-spectrum sunlight for more than 1,800 hours at 70 to 75 degrees Celsius, and estimate that the time required for the device to drop to eighty per cent of its peak performance is about 5,200 hours. Our demonstration of long-term operational, stable solar cells under intense conditions is a key step towards a reliable perovskite photovoltaic technology.

    Fulltekst (pdf)
    fulltext
  • 95. Baias, Maria
    et al.
    Dumez, Jean-Nicolas
    Svensson, Per Henrik
    KTH, Skolan för kemivetenskap (CHE), Kemi, Tillämpad fysikalisk kemi.
    Schantz, Staffan
    Day, Graeme M.
    Emsley, Lyndon
    De Novo Determination of the Crystal Structure of a Large Drug Molecule by Crystal Structure Prediction-Based Powder NMR Crystallography2013Inngår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 135, nr 46, s. 17501-17507Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The crystal structure of form 4 of the drug 4-[4-(2-adamantylcarbamoyl)-5-tert-butyl-pyrazol-1-yl]benzoic acid is determined using a protocol for NMR powder crystallography at natural isotopic abundance combining solid-state H-1 NMR spectroscopy, crystal structure prediction, and density functional theory chemical shift calculations. This is the first example of NMR crystal structure determination for a molecular compound of previously unknown structure, and at 422 g/mol this is the largest compound to which this method has been applied so far.

  • 96.
    Bamgbopa, Musbaudeen O.
    et al.
    Dubai Elect & Water Author DEWA, U Arab Emirates.
    Fetyan, Abdulmonem
    Dubai Elect & Water Author DEWA, U Arab Emirates.
    Vagin, Mikhail
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Adelodun, Adedeji A.
    Fed Univ Technol Akure, Nigeria.
    Towards eco-friendly redox flow batteries with all bio-sourced cell components2022Inngår i: Journal of Energy Storage, ISSN 2352-152X, E-ISSN 2352-1538, Vol. 50, artikkel-id 104352Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Recent research and few pilot deployments have demonstrated promising aqueous organic redox flow battery (RFB) systems. However, the claim that these organic RFB systems are eco-friendlier energy storage than Lithium-ion batteries and aqueous inorganic metallic RFB counterparts needs reinforcement, primarily if cell components other than redox-active species are still based on unsustainable materials. This thesis of the present work presents the prospects of achieving future eco-friendly RFBs with higher consideration for sustainability by adopting significant amounts of abundant bio-sourced/based materials for all main cell components. As we highlight the promising sources of the energy materials from a review of previous studies, we infer that plant derived quinones and other organic polymers may continue to dominate the organic redox-active species space. Furthermore, a candidate methodology to accomplish porous electrodes and membranes/separators of the eco-friendly RFBs is to apply stand-alone bio-based/sourced fibrils derived from cellulose, lignin, chitin, among other materials. These materials can be combined with (un)carbonised biomass or food wastes & residues to impart conductivity, catalytic activity, and ion selectivity. We explore symmetric chemistry as an ideal system for the eco-friendly RFBs of the discourse, given interplay between the electrolyte, electrode material and membrane dictates energy efficiency and cycling stability. These strategies also need to be coupled with further improvements to achieve reliability.

    Fulltekst (pdf)
    fulltext
  • 97. Banerjee, A.
    et al.
    Araujo, R. B.
    Sjödin, M.
    Ahuja, Rajeev
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Tillämpad materialfysik. Uppsala University, Sweden.
    Identifying the tuning key of disproportionation redox reaction in terephthalate: A Li-based anode for sustainable organic batteries2018Inngår i: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 47, s. 301-308Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The ever-increasing consumption of energy storage devices has pushed the scientific community to realize strategies toward organic electrodes with superior properties. This is owed to advantages such as economic viability and eco-friendliness. In this context, the family of conjugated dicarboxylates has emerged as an interesting candidate for the application as negative electrodes in advanced Li-ion batteries due to the revealed thermal stability, rate capability, high capacity and high cyclability. This work aims to rationalize the effects of small molecular modifications on the electrochemical properties of the terephthalate anode by means of first principles calculations. The crystal structure prediction of the investigated host compounds dilithium terephthalate (Li2TP) and diethyl terephthalate (Et2Li0TP) together with their crystal modification upon battery cycling enable us to calculate the potential profile of these materials. Distinct underlying mechanisms of the redox reactions were obtained where Li2TP comes with a disproportionation reaction while Et2Li0TP displays sequential redox reactions. This effect proved to be strongly correlated to the Li coordination number evolution upon the Li insertion into the host structures. Finally, the calculations of sublimation enthalpy inferred that polymerization techniques could easily be employed in Et2Li0TP as compared to Li2TP. Similar results are observed with methyl, propyl, and vinyl capped groups. That could be a strategy to enhance the properties of this compound placing it into the gallery of the new anode materials for state of art Li-batteries.

  • 98.
    Bao, Qinye
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten. East China Normal Univ, Peoples R China; Soochow Univ, Peoples R China.
    Liu, Xianjie
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Braun, Slawomir
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    Yang, Jianming
    East China Normal Univ, Peoples R China.
    Li, Yanqing
    Soochow Univ, Peoples R China.
    Tang, Jianxin
    Soochow Univ, Peoples R China.
    Duan, Chungang
    East China Normal Univ, Peoples R China.
    Fahlman, Mats
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ytors Fysik och Kemi. Linköpings universitet, Tekniska fakulteten.
    The Effect of Oxygen Uptake on Charge Injection Barriers in Conjugated Polymer Films2018Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 7, s. 6491-6497Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The energy offset between the electrode Fermi level and organic semiconductor transport levels is a key parameter controlling the charge injection barrier and hence efficiency of organic electronic devices. Here, we systematically explore the effect of in situ oxygen exposure on energetics in n-type conjugated polymer P(NDI2OD-T2) films. The analysis reveals that an interfacial potential step is introduced for a series of P(NDI2OD-T2) electrode contacts, causing a nearly constant downshift of the vacuum level, while the ionization energies versus vacuum level remain constant. These findings are attributed to the establishment of a so-called double-dipole step via motion of charged molecules and will modify the charge injection barriers at electrode contact. We further demonstrate that the same behavior occurs when oxygen interacts with p-type polymer TQ1 films, indicating it is possible to be a universal effect for organic semiconductOrs.

    Fulltekst (pdf)
    fulltext
  • 99. Barišić, Antun
    et al.
    Lützenkirchen, Johannes
    Bebić, Nikol
    Li, Qinzhi
    Hanna, Khalil
    Shchukarev, Andrey
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Begović, Tajana
    Experimental Data Contributing to the Elusive Surface Charge of Inert Materials in Contact with Aqueous Media2021Inngår i: Colloids and interfaces, E-ISSN 2504-5377, Vol. 5, nr 1, artikkel-id 6Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    We studied the charging of inert surfaces (polytetrafluoroethylene, i.e., PTFE; graphite; graphene; and hydrophobic silica) using classical colloid chemistry approaches. Potentiometric titrations showed that these surfaces acquired less charge from proton-related reactions than oxide minerals. The data from batch-type titrations for PTFE powder did not show an effect of ionic strength, which was also in contrast with results for classical colloids. In agreement with classical colloids, the electrokinetic results for inert surfaces showed the typical salt level dependence. In some cases, the point of zero net proton charge as determined from mass and tentatively from acid–base titration differed from isoelectric points, which has also been previously observed, for example by Chibowski and co-workers for ice electrolyte interfaces. Finally, we found no evidence for surface contaminations of our PTFE particles before and after immersion in aqueous solutions. Only in the presence of NaCl-containing solutions did cryo-XPS detect oxygen from water. We believe that our low isoelectric points for PTFE were not due to impurities. Moreover, the measured buffering at pH 3 could not be explained by sub-micromolar concentrations of contaminants. The most comprehensive explanation for the various sets of data is that hydroxide ion accumulation occurred at the interfaces between inert surfaces and aqueous solutions.

    Fulltekst (pdf)
    fulltext
  • 100.
    Barragan, Ana
    et al.
    IMDEA Nanosci Inst, Spain.
    Nicolas-Garcia, Tomas
    IMDEA Nanosci Inst, Spain.
    Lauwaet, Koen
    IMDEA Nanosci Inst, Spain.
    Sanchez-Grande, Ana
    IMDEA Nanosci Inst, Spain; Czech Acad Sci, Czech Republic.
    Urgel, Jose I
    IMDEA Nanosci Inst, Spain.
    Björk, Jonas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Materialdesign. Linköpings universitet, Tekniska fakulteten.
    Perez, Emilio M.
    IMDEA Nanosci Inst, Spain.
    Ecija, David
    IMDEA Nanosci Inst, Spain.
    Design and Manipulation of a Minimalistic Hydrocarbon Nanocar on Au(111)2023Inngår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 62, nr 6, artikkel-id e202212395Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Nanocars are carbon-based single-molecules with a precise design that facilitates their atomic-scale control on a surface. The rational design of these molecules is important in atomic and molecular-scale manipulation to advance the development of molecular machines, as well as for a better understanding of self-assembly, diffusion and desorption processes. Here, we introduce the molecular design and construction of a collection of minimalistic nanocars. They feature an anthracene chassis and four benzene derivatives as wheels. After sublimation and adsorption on an Au(111) surface, we show controlled and fast manipulation of the nanocars along the surface using the tip of a scanning tunneling microscope (STM). The mechanism behind the successful displacement is the induced dipole created over the nanocar by the STM tip. We utilized carbon monoxide functionalized tips both to avoid decomposition and accidentally picking the nanocars up during the manipulation. This strategy allowed thousands of maneuvers to successfully win the Nanocar Race II championship.

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