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Wyszukujesz frazę "Jansen, J." wg kryterium: Autor


Wyświetlanie 1-12 z 12
Tytuł:
Structure Prediction for PbS and ZnO at Different Pressures and Visualization of the Energy Landscapes
Autorzy:
Zagorac, D.
Schön, J.
Doll, K.
Jansen, M.
Powiązania:
https://bibliotekanauki.pl/articles/1502980.pdf
Data publikacji:
2011-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.50.Ah
61.66.Fn
61.50.Ks
71.50.Nc
Opis:
An important issue in modern solid state chemistry is the development of a general methodology to predict the possible (meta)-stable modifications of a solid. This requires the global exploration of the energy landscape of the chemical system, since each stable phase corresponds to a locally ergodic region of the landscape. The global search in the lead sulfide system has been performed with simulated annealing on the ab initio level, while zinc oxide was studied with an empirical potential using simulated annealing, both at standard and elevated pressure (up to 100 GPa). The local optimization of the modifications found in the PbS system was performed using various density functionals. Next, the energy E(V) and enthalpy H(p) as function of volume and pressure, respectively, were computed for these modifications and their electronic structure was analyzed. The structures found for ZnO were locally optimized on ab initio level (DFT and Hartree-Fock). In both systems the structures found were in good agreement with the experiment. Furthermore, we employed the threshold algorithm to explore the barrier structure of the landscape of ZnO as function of the number of formula units in the simulation cell. Based on the barrier and minima information 2-D models of the energy landscape were constructed.
Źródło:
Acta Physica Polonica A; 2011, 120, 2; 215-220
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Applications of Scanning Tunneling Microscopy To Solid State Physics
Autorzy:
van Kempen, H.
Boon, E. J. G.
van der Wielen, M. C. M. M.
Wildöer, J. W. G.
Prins, M.
Jansen, R.
Schad, R.
Powiązania:
https://bibliotekanauki.pl/articles/1968742.pdf
Data publikacji:
1998-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.16.Ch
68.35.Dv
71.55.Eq
Opis:
Due to the dependence of the tunnel current to material properties like work function, density of states, and spin polarization the scanning tunneling microscope can be used to study a number of solid state physics problems. This will be illustrated with some examples. The presented examples have in common that also the role of the tip properties have to be taken explicitly into account.
Źródło:
Acta Physica Polonica A; 1998, 93, 2; 323-331
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of PCBs and PAHs levels in European coastal waters using mussels from the Mytilus edulis complex as biomonitors
Autorzy:
Olenycz, M.
Sokolowski, A.
Niewinska, A.
Wolowicz, M.
Namiesnik, J.
Hummel, H.
Jansen, J.
Powiązania:
https://bibliotekanauki.pl/articles/48472.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
polychlorinated biphenyl
polycyclic aromatic hydrocarbon
organic pollutant
biomonitoring
mussel
Mytilus edulis
coastal water
pollution
Źródło:
Oceanologia; 2015, 57, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conceptual processes for zeolite membrane based hydroisomerization of light alkanes
Autorzy:
Maloncy, M. L.
Gora, L.
Jansen, J. C.
Maschmeyer, Th.
Powiązania:
https://bibliotekanauki.pl/articles/347005.pdf
Data publikacji:
2003
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
zeolite membrane
hydroisomerization
separation
conceptual process
hexane
heptane
Opis:
A zeolite membrane reactor concept for the hydroisomerization of n-hexane was applied experimentally. The results indicate separation selectivities with factors close to 20 for n-, mono- and dibranched components in a gas mixture, as well as nhexane conversions up to equilibrium values. The research octane number calculated for the product stream of the different experiments indicates numbers as high as 85. For the hydroisomerization of C7 alkanes, a concept of two reactors and a zeolite membrane was proposed and an industrial scale process was simulated. A high octane number product containing tribranched, and a part of dibranched, C7 isomers is predicted. Although the product yield was calculated to be only 24% of the process feed, there was an improvement in a research octane number from 57 for the feed to 92 for the product. Both processes show that the application of zeolite membranes in the hydroisomerization of light alkanes can results in a octane number higher, than in the "state of the art" processes. The membrane unit, however, is the main cost driver of the processes, thus, the economical feasibility of industrial scale light alkanes hydroisomerization processes using zeolite membranes is restricted to its further commercial development.
Źródło:
Ars Separatoria Acta; 2003, 2; 18-28
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Amsterdam waterfront development - An social-geographical overview
Autorzy:
Jansen, J.
Powiązania:
https://bibliotekanauki.pl/articles/2078334.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Warszawski. Wydział Geografii i Studiów Regionalnych
Opis:
Development of the city of Amsterdam, capital of the Netherlands, has always been related to waterfront activities. The port of Amsterdam is still the 4th transshipment port of Europe and the city authorities see both the port and the waterfront as important components of economic base for the city development. Amsterdam has experienced similar development trends as many other European cities of this size. Among them were suburbanization and urban sprawl. These problems were addressed by national spatial policy, which led to identifying regional 'growth cities ' and suburban new towos that were supposed to accommodate those who wanted to move to suburbs. This policy called 'concentrated de-concentration ' further stimulated the suburbanization and Amsterdam's central districts became dominated by empty houses. The remaining population of the city mainly consisted of poor and often unemployed elderly Amsterdam born people and low-skilled immigrants. Other parts of the city also experienced degradation. Because of the deindustrialization of the city 's economy the Eastern Docklands, central waterfront and north bank former industrial areas became deserted wastelands in the 80's, occupied by squatters, boat dwellers and city nomads. Some of them looked like 'no-go' areas. Development paths of the Amsterdam waterfront have been shaped by industrial development of the city and changing role of the port. The open waterfront of the historical city center of Amsterdam was closed by the construction of the railway and Central Station in the 19th century. A discussion about a location of the central railway station at the south or north part of the historical city center was ended by the decision of the national govemment for a construction at the north part in the waterfront. lndustrialized harbor activities shifted to the east part of the city, where man-made islands were built. In the 20th century, the harbor moved to the western edge of the city. The regeneration of the waterfront has been related to evolution of the city's economy and transition from mercantile center to metropolitan city - center of services offered at the global scale and characterized by well-developed knowledge-based economy. The transition experienced by the Amsterdam is closely connected with the shift from the concept of a city government, which provides services and provisions for the benefit of its inhabitants, towards a city govemment, which competes with other cities to attract businesses and well qualified and creative people. Amsterdam sees its waterfront as a component that might help to build its attractiveness. City authorities use the transformation of abandoned former industrial sites to attract creative and knowledge based firms. In recent Amsterdam urban development the waterfront is being developed as a mixed area of housing, cultural and business functions. The planning approach is also an important factor that has impact on transformation of the waterfront. Since the 90's the national planning approach became more market oriented. Densification of housing and economy in urban cores became an objective of national spatial policy. The city's planners were forced to cooperate with private parties under Private Public Partnership framework. The master-plan for the Eastern Docklands had to be revised and phased, because parts of the area were not yet ready to be redeveloped. There are some other obstacles in transformation of the waterfront. In the west part of the waterfront heavy industries are located. The City Authorities are discussing with the Port authority about the gradual relocations of heavy industries towards the more western parts of the harbor area. Also plans are discussed with the national government for investments in a metro connection to the east polders, crossing the water towards the new town of Almere. Thus the future strategies for waterfront developments are becoming more and more regional. Development of the Amsterdam waterfront has brought some important lessons. The process of development (which is still going on) has been a process of trial and error. The planning process started 30 years ago. For the most complex south bank development, a series of plans were made. The municipality had a steering role all the time, but the planning approach shifted from a big master-plan and PPP-constructions towards a more modest but strategic approach with targeted municipal investments in separate areas, bounded by an overall vision of seducement of private investments, 'anchoring' cultural functions and an overall high-quality public-space plan. Future transformation plans are more gradually implemented, in an ongoing communicative approach towards different stakeholders. Experience from Amsterdam also proved efficiency and attractiveness of an integrated landscape design. Not only for residential functions, which are situated at the waterfront, but also smaller and bigger business and creative industry functions. The open space of the water made it possible to mix high density attractive housing with working areas. The now ongoing transformation process of the north bank has a less massive approach in comparison with the south bank waterfront development. Cultural functions that originated from spontaneous occupations of deserted harbor sites, now turn out to be an attractive element for creative business firms. Amsterdam waterfront developments were successful in giving the city an economic boost and gave residents the possibility for housing careers in attractive living environments within their own city. Housing prices in the waterfront residential areas are among the highest in the city, but still a relatively mixed neighborhoods were possible through a substantial amount of public housing. Amsterdam political tradition is not in favor of socially segregated areas and the concept of the 'undivided' city stili holds strong. Amsterdam waterfront developments turned out to be successful after a long period of looking for the right planning approach. The transformations and debates are stili going on. Finding a way, which fits the path dependency of a city's development, is one of the key issues in successful urban revital ization.
Źródło:
Prace i Studia Geograficzne; 2015, 60; 107-126
0208-4589
Pojawia się w:
Prace i Studia Geograficzne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acceleration of gelation and promotion of mineralization of chitosan hydrogels by alkaline phosphatase
Autorzy:
Douglas, T. E. L.
Skwarczyńska, A.
Modrzejewska, Z.
Balcaen, L.
Schaubroeck, D.
Lycke, S.
Vanhaecke, F.
Vandenabeele, P.
Dubruel, P.
Jansen, J. A.
Leeuwenburgh, S. C. G.
Powiązania:
https://bibliotekanauki.pl/articles/284363.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
chitosan
thermosensitivity
composite
mineralization
Opis:
Thermosensitive chitosan hydrogels containing sodium beta-glycerophosphate (ß-GP), whose gelation is induced by increasing temperature to body temperature, were functionalized by incorporation of Alkaline Phosphatase (ALP), an enzyme involved in mineralization of bone. ALP incorporation led to acceleration of gelation upon increase of temperature for four different chitosan preparations of differing molecular weight, as demonstrated by rheometric time sweeps at 37°C. Hydrogels containing ALP were subsequently incubated in calcium glycerophosphate (Ca-GP) solution to induce their mineralization with calcium phosphate (CaP) in order to improve their suitability as materials for bone replacement. Incorporated ALP retained its bioactivity and induced formation of CaP mineral, as confirmed by SEM, FTIR, Raman spectroscopy, XRD, ICP-OES, and increases in dry mass percentage, which rose with increasing ALP concentration and incubation time in Ca-GP solution. The results demonstrate that ALP accelerates formation of thermosensitive chitosan/ß-GP hydrogels and induces their mineralization with CaP, which paves the way for applications as injectable bone replacement materials.
Źródło:
Engineering of Biomaterials; 2012, 15, no. 116-117 spec. iss.; 135-136
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Composite collagen-calcium phosphate hydrogels for bone substitution
Autorzy:
Douglas, T. E. L.
Gkioni, C.
Jansen, J. A.
Leeuwenburgh, S. C. G.
Powiązania:
https://bibliotekanauki.pl/articles/283747.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
hydrogels
bone substitution
collagen
Źródło:
Engineering of Biomaterials; 2009, 12, no. 89-91; 28-29
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enzymatyczna mineralizacja hydrożelów glikolu katecholopolyetylenowego (cPEG) w zastosowaniach jako kostny materiał zastępczy
Enzymatic mineralization of catechol-polyethylene glycol (cPEG) hydrogels for bone replacement applications
Autorzy:
Douglas, T. E. L.
Messersmith, P. B.
Jansen, J. A.
Leeuwenburgh, S. C. G.
Powiązania:
https://bibliotekanauki.pl/articles/285192.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Tematy:
hydrożele
mineralizacja kości
fosfataza alkaliczna
hydrogels
bone mineralization
alkaline phosphatase
Opis:
Fosfataza alkaliczna (ALP), enzym odgrywający rolę w mineralizacji kości, został związany wewnątrz kleistego hydrożelu chemicznie zbliżonego do białek omulków, składającego się z glikolu katecholo-polyetylenowego (cPEG). Następnie, przygotowane hydrożele zostaly zanurzone w roztworze glycerofosforanu wapniowego (CaGP) w celu ich zmineralizowania i poprzez to polepszenia ich przydatności jako materiał zastępczy kości. Związany ALP zachował swoją bioaktywność i przyczynił się do tworzenia materialu podobnego do apatytu wewnątrz cPEG-żelów. Ilość tego materiału oraz wytrzymałość mechaniczna wzrastały zarówno wraz ze zwiększeniem okresu inkubacyjnego jak i stężenia fosfatazy. Wyniki pokazują zasadę dzialania mineralizacji za pośrednictwem fosfatazy ALP.
Alkaline Phosphatase (ALP), an enzyme involved in mineralization of bone, was incorporated into mussel protein-inspired adhesive hydrogels consisting of catechol-polyethylene glycol (cPEG) and incubated in calcium glycerophosphate (CaGP) solution to induce their mineralization with a view to improving their suitability as materials for bone replacement. Incorporated ALP retained its bioactivity and induced formation of apatite-like material within cPEG gels which rose with increasing incubation time and ALP concentration, as well as an increase in mechanical strength. The results prove the principle of ALP-mediated enzymatic mineralization.
Źródło:
Engineering of Biomaterials; 2010, 13, no. 99-101; 105-106
1429-7248
Pojawia się w:
Engineering of Biomaterials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and comparison of superconducting linear actuators for highly dynamic motion
Autorzy:
de Bruyn, B. J. H.
Jansen, J. W.
Lomonova, E. A.
Powiązania:
https://bibliotekanauki.pl/articles/141560.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
linear motors
loss calculation
high-temperature superconductors
HTS
Opis:
This paper presents a numerical modeling method for AC losses in highly dynamic linear actuators with high temperature superconducting (HTS) tapes. The AC losses and generated force of two actuators, with different placement of the cryostats, are compared. In these actuators, the main loss component in the superconducting tapes are hysteresis losses, which result from both the non-sinusoidal phase currents and movement of the permanent magnets. The modeling method, based on the H-formulation of the magnetic fields, takes into account permanent magnetization and movement of permanent magnets. Calculated losses as function of the peak phase current of both superconducting actuators are compared to those of an equivalent non-cryogenic actuator.
Źródło:
Archives of Electrical Engineering; 2015, 64, 4; 559-570
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of electric field control methods for foil coils in high-voltage linear actuators
Autorzy:
Beek, T. A. van
Jansen, J. W.
Lomonova, E. A.
Powiązania:
https://bibliotekanauki.pl/articles/141173.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric field control methods
high voltage
linear actuators sensitivity analysis
stress grading
Opis:
This paper describes multiple electric field control methods for foil coils in high-voltage coreless linear actuators and their sensitivity to misalignment. The investigated field control methods consist of resistive, refractive, capacitive and geometrical solutions for mitigating electric stress at edges and corners of foil coils. These field control methods are evaluated using 2-D boundary element and finite element methods. A comparison is presented between the field control methods and their ability to mitigate electric stress in coreless linear actuators. Furthermore, the sensitivity to misalignment of the field control methods is investigated.
Źródło:
Archives of Electrical Engineering; 2015, 64, 4; 629-640
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Field Dependent Effective Mass in the Organic Superconductor κ-(BEDT-TTF)$\text{}_{2}$I$\text{}_{3}$
Autorzy:
Balthes, E.
Schweitzer, D.
Heinen, I.
Keller, H. J.
Biberacher, W.
Jansen, A. G. M.
Steep, E.
Powiązania:
https://bibliotekanauki.pl/articles/1933336.pdf
Data publikacji:
1995-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.Kn
71.25.Hc
71.25.Jd
Opis:
κ-(BEDT-TTF)$\text{}_{2}$I$\text{}_{3}$ is an electronically extreme two-dimensional organic metal with a superconducting transition at around 4 K. In magnetic fields above 12 T the effective mass, as obtained from the temperature dependence of the amplitudes of Shubnikov-de Haas oscillations, is magnetic field dependent as long as the magnetic field is arranged perpendicular to the conducting planes. In contrast to this, by turning the magnetic field by 27° or even only 9° the observed effective mass (as obtained from Shubnikov-de Haas and de Haas-van Alphen measurements) is field independent. We suppose that the occurrence of anyons at temperatures below 1 K in fields above 12 T is the reason for the observed field dependence of the effective mass.
Źródło:
Acta Physica Polonica A; 1995, 87, 4-5; 767-772
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occurrence of trace metals of toxicological potential in common grass African foxtail (Cenchrus ciliaris)
Autorzy:
Awofolu, O.R.
Iikela, H.
Jansen, C.
Hidinwa, J.
Powiązania:
https://bibliotekanauki.pl/articles/9995.pdf
Data publikacji:
2017
Wydawca:
Fundacja na Rzecz Młodych Naukowców
Tematy:
environment contamination
pollution
trace metal
occurrence
toxicological property
grass
African foxtail zob.African foxtail grass
buffel-grass zob.African foxtail grass
African foxtail grass
Cenchrus ciliaris
Namibia
Opis:
Anthropogenic activities often result in the introduction of noxious contaminants into the environment with resultant distribution and transfer across the food chain. This study reports on the level of trace metals (Cd, Pb, Cu and Zn) in African foxtail (Cenchrus ciliaris) plant; widely referred to as “common grass” and possible implication across the food chain. Plant samples were collected from stratified study area, processed and analysed using validated acid leaching protocols. Instrumental analysis of the metallic content was by ICP-OES. Quality assurance of the analytical protocol revealed its’ applicability to the environmental samples through metallic recoveries (n=3) in the range of 85.6 – 91 %. The overall mean concentration of analysed metals in samples ranged from 9.34 mg/kg – 38.6 mg/kg; 64.2 mg/kg – 105.2 mg/kg; 0.28 mg/kg – 0.73 mg/kg and 0.54 mg/kg – 16.3 mg/kg for Cu, Zn, Cd and Pb respectively across SCP1-SCP4. Incremental order of analysed trace metals across the SCPs were Cu: SCP1>SCP2>SCP3>SCP4; Zn: SCP1>SCP2>SCP3> SCP4; Cd: SCP1>SCP2>SCP3 = SCP4 and Pb: SCP1>SCP2> SCP3>SCP4. Strong correlation (r > 0.99) was obtained between all the analysed trace metals. Significant difference at (p < 0.05) was found between the analysed metals and SCP 1 while those between the metals and SCPs 2- 4 were non-significant. Accumulation of these metals in ruminants and transfer across the food chain is most probable.
Źródło:
Environment, Earth and Ecology; 2017, 1, 2
2543-9774
2451-4225
Pojawia się w:
Environment, Earth and Ecology
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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