Artykuły w czasopismach: „Surface sites”

1

Smirnova, O. S., A. G. Grebenyuk i V. V. Lobanov. "Titanium dioxide defect structures as catalytic sites". Surface 9(24) (30.12.2017): 44–56. http://dx.doi.org/10.15407/surface.2017.09.044.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

2

Filonenko, О. V., E. M. Demianenko i V. V. Lobanov. "Quantum chemical modeling of orthophosphoric acid adsorption sites on hydrated anatase surface". Surface 12(27) (30.12.2020): 20–35. http://dx.doi.org/10.15407/surface.2020.12.020.

Pełny tekst źródła

Streszczenie:

Quantum chemical modeling of orthophosphoric acid adsorption sites on the hydrated surface of anatase was performed by the method of density functional theory (exchange-correlation functional PBE0, basis set 6-31 G(d,p)). The influence of the aqueous medium was taken into account within the framework of the continual solvent model. The work uses a cluster approach. The anatase surface is simulated by a neutral Ti(OH)4(H2O)2 cluster. The results of analysis of the geometry and energy characteristics of all the calculated complexes show that the highest interaction energy is inherent to the intermolecular complex of orthophosphoric acid and hydrated surface of anatase, where the oxygen atom of the phosphoryl group (О=Р≡) forms a hydrogen bond with a hydrogen atom of the coordinated water molecule of Ti(OH)4(H2O)2 cluster and two hydrogen atoms of the hydroxyl groups of the orthophosphoric acid molecule form two hydrogen bonds with two oxygen atoms of the titanol groups. The formation energy effect of this complex is -134.0 kJ/mol. The formation energy effect of the complex with separated charges by the proton transfer from the molecule H3PO4 to the Ti(OH)4(H2O)2 cluster with the formation of dihydrogen phosphate anion and the protonated form of the titanol group (º) is -131.1 kJ/mol, so indicating less thermodynamic probability of such intermolecular interaction. The smallest thermodynamic probability (-123.9 kJ/mol) of complexation between orthophosphoric acid and hydrated anatase surface where a water molecule moves from the coordination sphere of the titanium atom. The calculation results indicate a possible adsorption of the H3PO4 molecule in an aqueous solution on the hydrated anatase surface. Taking into account the effect of the solvent within the polarization continuum insignificantly changes the adsorption energy, which is -44.5 kJ/mol; for vacuum conditions this value is -49.0 kJ/mol.

Style APA, Harvard, Vancouver, ISO itp.

3

DEO, G. "Surface oxide-support interaction (SOSI) for surface redox sites". Journal of Catalysis 129, nr 1 (maj 1991): 307–12. http://dx.doi.org/10.1016/0021-9517(91)90036-4.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

4

SHRESTHA, NRIPENDRA L., YOUHEI KAWAGUCHI i TAKENAO OHKAWA. "SUMOMO: A PROTEIN SURFACE MOTIF MINING MODULE". International Journal of Computational Intelligence and Applications 04, nr 04 (grudzień 2004): 431–49. http://dx.doi.org/10.1142/s1469026804001392.

Pełny tekst źródła

Streszczenie:

Protein surface motifs, which can be defined as commonly appearing patterns of shape and physical properties in protein molecular surfaces, can be considered "possible active sites". We have developed a system for mining surface motifs: SUMOMO which consists of two phases: surface motif extraction and surface motif filtering. In the extraction phase, a given set of protein molecular surface data is divided into small surfaces called unit surfaces. After extracting several common unit surfaces as candidate motifs, they are repetitively merged into surface motifs. However, a large amount of surface motifs is extracted in this phase, making it difficult to distinguish whether the extracted motifs are significant to be considered active sites. Since active sites from proteins with a particular function have similar shape and physical properties, proteins can be classified based on similarity among local surfaces. Thus, in the filtering phase, local surfaces extracted from proteins of the same group are considered significant motifs, and the rest are filtered out. The proposed method was applied to discover surface motifs from 15 proteins belonging to four function groups. Motifs corresponding to all 4 known functional sites were recognised.

Style APA, Harvard, Vancouver, ISO itp.

5

Carl, Nejc, Janez Konc i Dušanka Janežič. "Protein Surface Conservation in Binding Sites". Journal of Chemical Information and Modeling 48, nr 6 (14.05.2008): 1279–86. http://dx.doi.org/10.1021/ci8000315.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

6

Woods, I. T., i B. S. Haynes. "Soot surface growth at active sites". Combustion and Flame 85, nr 3-4 (czerwiec 1991): 523–25. http://dx.doi.org/10.1016/0010-2180(91)90156-6.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

7

Vurdu, Can Doğan. "The Adsorption and Diffusion Manners of Hydrogen Atoms on Pt (100), Pt (110), and Pt (111) Surfaces". Advances in Condensed Matter Physics 2018 (10.09.2018): 1–10. http://dx.doi.org/10.1155/2018/4186968.

Pełny tekst źródła

Streszczenie:

In this study, the interactions between H atoms and the (100), (110), and (111) surfaces of platinum have been investigated by using the London-Eyring-Polanyi-Sato (LEPS) potential function. The adsorption zones (sites) and LEPS energy values of these sites have been determined theoretically. In addition, the potential-energy surfaces for each Pt surface have been obtained in detail. Further, the adsorption sites on the surface, scattering from the surface, diffusion paths on the surface, and transition regions to the subsurface, have been determined and the differences have been examined in detail among the surfaces. From these results, it is found that an H atom has the lowest binding energy at the hollow sites on the Pt (100) and Pt (111) surfaces and that it has the lowest binding energy at the long-bridge sites on the Pt (110) surface. It has also been determined that the hollow sites on the three surfaces are the regions through which H atoms can penetrate into the subsurface. In addition, it has also been found that, for each of the three Pt surfaces, the diffusion of an H atom across the surface may follow a bridge-hollow-bridge pathway. These results are in agreement with previous experimental and theoretical results. Besides, the adsorption and diffusion manners of hydrogen atoms on each of the Pt surfaces have been analyzed deeply.

Style APA, Harvard, Vancouver, ISO itp.

8

Tokarz-Sobieraj, Renata, i Malgorzata Witko. "Electronic Properties of the Active Sites Present at the (011) Surface of MoO2". Adsorption Science & Technology 25, nr 8 (październik 2007): 583–96. http://dx.doi.org/10.1260/0263-6174.25.8.583.

Pełny tekst źródła

Streszczenie:

The DFT method was used to describe the electronic structure of the catalytically interesting (011) surface of molybdenum dioxide, with attention being particularly focused on the properties of the active sites, both molybdenum and oxygen, present at this surface. In addition, a comparison of (011)MoO2 and (100)MoO3 surfaces was undertaken since both surfaces contain not only differently coordinated oxygen sites but also the bare molybdenum centres. The electronic structures of both surfaces were obtained using the cluster method and DFT approach. The local properties of the different surface sites exposed at the (011)MoO2 surface, viz. five- and six-fold coordinated Mo atoms and nucleophilic O sites with different coordination numbers, have been discussed using charge densities, bond-order indices and molecular orbital diagrams.

Style APA, Harvard, Vancouver, ISO itp.

9

Kosmulski, Marek. "The Surface Charging at Low Density of Protonatable Surface Sites". Langmuir 21, nr 16 (sierpień 2005): 7421–26. http://dx.doi.org/10.1021/la051019o.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

10

Bapeer, Suzan B., i Dalshad A. Darwesh. "IMPACTS OF OPEN DUMPSITE LEACHATE ON SOIL ENZYMATIC ACTIVITY IN KANI-QRZHALA OPEN DUMPSITE – ERBIL CITY". Science Journal of University of Zakho 11, nr 2 (28.05.2023): 232–36. http://dx.doi.org/10.25271/sjuoz.2023.11.2.1059.

Pełny tekst źródła

Streszczenie:

The study was carried out to assess the effect of open dump site leachate on soil enzymes activity. Soil samples were collected in Kani-Qrzhala open dump site in Erbil city in four sites (Site1, Site2, Site3 and Site4) for different depths; surface ,30cm,60cm and 90 cm following the edge drainage pathway of leachate. The results of dehydrogenase, urease and catalase show a significant variation at significant levels (P⩽0.01) and (P⩽0.05) respectively. The highest rates of dehydrogenase, urease and catalase (77.69 µg TPF.g-1, 454.50 µg N.g-1, and 1.927µg H2O2.g-1), were recorded at surface point in all sites, while the lowest rates of all enzymes were recorded at 90 cm respectively, this is indicating that the soil depth adversely affected enzymes activity. Using oak tree wood and walnut shell biochar by 10% as a treatment to polluted soil, significantly increased enzymes activity. Walnut shell biochar was more suitable than oak tree wood biochar to catalase and urease activity, where urease was increased by 133.61% and catalase by 63.40%, while dehydrogenase activity was increased by 95.07% after using oak tree wood biochar which was more suitable than walnut shell biochar. This was related to the feedstock and technology production of biochar that affected on biochar structure and activity, however in this study, biochar application generally had a positive effect on enzymes activity and soil depth had an adverse effect.

Style APA, Harvard, Vancouver, ISO itp.

11

Gorelov, B. M., O. V. Mischanchuk i N. V. Sigareva. "Anomalous thermal stability of atomic destruction fragments in polymer nanocomposites". Surface 15(30) (30.12.2023): 135–45. http://dx.doi.org/10.15407/surface.2023.15.135.

Pełny tekst źródła

Streszczenie:

Thermal destruction of composites of ureaformaldehyde (UPR) and polyester resins (PER) with silicon dioxide nanoparticles having a specific surface area of 280 m2/g, titanium dioxide and titanosilicate with a specific surface area of 40 and 48 m2/g, respectively, when a filler content is no more than 5.0 wt% have been studied. The investigations were performed using The thermally programmed mass spectrometry method with registration of the masses of desorbed atomic fragments in the 10 ‒ 200 m/z range. It was established that during the main polymer mass destruction at 150 ‒ 350 oC, along with low temperature decomposition products, anomalously high thermal resistance of a number of atomic fragments of polymer chains and cross-links are recorded. The atomic composition of destruction fragments and their desorption temperature in the range 400 ‒ 700 oС were determined. It was established that in composites of ureaformaldehyde resin with SiO2 and TiO2 nanoparticles the high temperature resistance of fragments with m/z 27 exhibits due to the formation of strong bonds among the Si and Ti surface sites and the nitrogen atoms of the polymer. Such thermal stability is not realized in resin loading with (Si/Ti)O2 nanoparticles. In composites of polyester resin with silica a high-temperature destruction of oxygen atoms from polyester chains realizes at temperatures of 290 ‒ 400 oC and a low-intensity wide destruction band takes place in the temperature range 400 ‒ 700 oC. In addition, in the temperature range of 400-700 oC cross-links are destroyed with the release of benzene rings and styrene molecules. It was established that anomalously high-temperature desorption is typical for atomic fragments of the polymer structure attached to surface Si and Ti sites through nitrogen or carbon atoms from the polymer structure. Thus, in UPR composites with silicon and titanium oxides, strong chemical nitride bonds of the form Si-N≡C-H and Ti-N≡C-H are formed, which demonstrate anomalously high heat resistance. It is shown that in composites of polyester resin with silicon dioxide nanoparticles, the high-temperature destruction of fragments is due to their desorption from the surface of silicon dioxide particles when breaking their bonds with silicon atoms. Thus, polymer matrices have been determined, in which atomic fragments of the macromolecule, binding to the surface centers of fillers, significantly weaken the thermal destruction of composites due to the formation of strong chemical and coordination bonds.

Style APA, Harvard, Vancouver, ISO itp.

12

Santos, M., i W. Figueiredo. "Growth surface model with non active sites". Brazilian Journal of Physics 34, nr 2a (czerwiec 2004): 429–32. http://dx.doi.org/10.1590/s0103-97332004000300020.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

13

Brierley, Martin, John Knowles, Neil Montgomery i Michael Preuss. "Microstructure of surface cerium hydride growth sites". Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films 32, nr 3 (maj 2014): 031402. http://dx.doi.org/10.1116/1.4867475.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

14

Mitchell, S. R. "Analysis of Some Australian Aboriginal Surface Sites". Mankind 5, nr 11 (10.02.2009): 466–70. http://dx.doi.org/10.1111/j.1835-9310.1962.tb00276.x.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

15

Berruyer, Pierrick, Moreno Lelli, Matthew P. Conley, Daniel L. Silverio, Cory M. Widdifield, Georges Siddiqi, David Gajan, Anne Lesage, Christophe Copéret i Lyndon Emsley. "Three-Dimensional Structure Determination of Surface Sites". Journal of the American Chemical Society 139, nr 2 (5.01.2017): 849–55. http://dx.doi.org/10.1021/jacs.6b10894.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

16

Coluccia, Salvatore, i Leonardo Marchese. "Surface sites of microcrystals: Coordination and reactivity". Catalysis Today 41, nr 1-3 (maj 1998): 229–38. http://dx.doi.org/10.1016/s0920-5861(98)00052-2.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

17

Yates, John T. "Surface chemistry at metallic step defect sites". Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films 13, nr 3 (maj 1995): 1359–67. http://dx.doi.org/10.1116/1.579564.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

18

Holmblad, P. M., J. Hvolb�k Larsen, I. Chorkendorff, L. Pleth Nielsen, F. Besenbacher, I. Stensgaard, E. L�gsgaard, P. Kratzer, B. Hammer i J. K. N�rskov. "Designing surface alloys with specific active sites". Catalysis Letters 40, nr 3-4 (1996): 131–35. http://dx.doi.org/10.1007/bf00815272.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

19

Gun'ko, V. M., J. Skubiszewska i B. Charmas. "Hybrid composites prepared by carbonization of acetylacetone and metal acetylacetonates on a surface of silica gel". SURFACE 14(29) (30.12.2022): 159–75. http://dx.doi.org/10.15407/surface.2022.14.159.

Pełny tekst źródła

Streszczenie:

Hybrid adsorbents with carbon/silica, carbon/metal oxide/silica, and carbon/metal/silica could be of interest from a practical point of view since they can effectively adsorb both polar and nonpolar compounds. Therefore, mesoporous silica gel Si–60 modified by carbonization acetylacetone or Ti, Zn, Ni, Co, Cr, Zr acetylacetonates has been studied using nitrogen and water adsorption–desorption, thermogravimetry, transmission electron microscopy, X–ray diffraction, and X–ray fluorescence methods. Grafted C/X phases consist of metal compounds (X denotes metal oxide or silicate or/and metal) and char, whose characteristics can be varied changing metal in the precursors and their amounts. The morphological, structural, and textural characteristics of C/X/SiO2, such as composition and particle size distributions of deposits, a number and kind of polar and non polar surface sites, specific surface area, pore volume, and pore size distributions depend on the type, content, and distribution of the C/X deposits. The changes in the grafted matters occur with increasing precursor and C/X concentrations and a possible catalytic effect of the X phases on the carbonization reactions. Appropriate selection of precursor structure and amounts allows one to vary and control the characteristics of whole hybrid adsorbents that is of importance from a practical point of view.

Style APA, Harvard, Vancouver, ISO itp.

20

Andrić, Stevan, Ivana Jokić, Jelena Stevanović, Marko Spasenović i Miloš Frantlović. "Noise Spectrum as a Source of Information in Gas Sensors Based on Liquid-Phase Exfoliated Graphene". Chemosensors 10, nr 6 (14.06.2022): 224. http://dx.doi.org/10.3390/chemosensors10060224.

Pełny tekst źródła

Streszczenie:

Surfaces of adsorption-based gas sensors are often heterogeneous, with adsorption sites that differ in their affinities for gas particle binding. Knowing adsorption/desorption energies, surface densities and the relative abundance of sites of different types is important, because these parameters impact sensor sensitivity and selectivity, and are relevant for revealing the response-generating mechanisms. We show that the analysis of the noise of adsorption-based sensors can be used to study gas adsorption on heterogeneous sensing surfaces, which is applicable to industrially important liquid-phase exfoliated (LPE) graphene. Our results for CO2 adsorption on an LPE graphene surface, with different types of adsorption sites on graphene flake edges and basal planes, show that the noise spectrum data can be used to characterize such surfaces in terms of parameters that determine the sensing properties of the adsorbing material. Notably, the spectrum characteristic frequencies are an unambiguous indicator of the relative abundance of different types of adsorption sites on the sensing surface and their surface densities. We also demonstrate that spectrum features indicate the fraction of the binding sites that are already occupied by another gas species. The presented study can be applied to the design and production of graphene and other sensing surfaces with an optimal sensing performance.

Style APA, Harvard, Vancouver, ISO itp.

21

Wang, Kun, Kunlun Li i Fuqing Wang. "Study on the Adsorption Properties and Mechanisms of CO on Nickel Surfaces Based on Density Functional Theory". Energies 16, nr 1 (3.01.2023): 525. http://dx.doi.org/10.3390/en16010525.

Pełny tekst źródła

Streszczenie:

In this work, the adsorption of CO onto the surface of the transition metal Ni at different coverage levels was explored based on the density functional theory (DFT). The corresponding periodic slab plate models were established, and the adsorption parameters and CO electronic states on different nickel surfaces under different coverage (0.11 mL, 0.25 mL and 0.5 mL) were calculated. The results showed that the most stable adsorption sites on Ni (111) and Ni (100) crystal surfaces were valley sites, while the most stable adsorption sites on a Ni (110) surface was a short bridge site. By comparing the energy of the same adsorption sites, it was found that the adsorption of CO on a Ni (100) crystal surface was superior to the other two surfaces. Furtherly, from the perspective of the electronic structure, the density of states (DOSs) of Ni atoms and CO molecules were calculated before and after adsorption. The density of states showed that the main factor of surface adsorption generation originates from hybridization among the orbitals. This article provides insight into the mechanisms of the nickel adsorption of CO.

Style APA, Harvard, Vancouver, ISO itp.

22

Estes, Deven P., Georges Siddiqi, Florian Allouche, Kirill V. Kovtunov, Olga V. Safonova, Alexander L. Trigub, Igor V. Koptyug i Christophe Copéret. "C–H Activation on Co,O Sites: Isolated Surface Sites versus Molecular Analogs". Journal of the American Chemical Society 138, nr 45 (7.11.2016): 14987–97. http://dx.doi.org/10.1021/jacs.6b08705.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

23

Ruan, Ting, Binjun Wang, Chun Xu i Yunqiang Jiang. "Shear Deformation Helps Phase Transition in Pure Iron Thin Films with “Inactive” Surfaces: A Molecular Dynamics Study". Crystals 10, nr 10 (23.09.2020): 855. http://dx.doi.org/10.3390/cryst10100855.

Pełny tekst źródła

Streszczenie:

In a previous study, it was shown that the (111)fcc, (110)fcc and (111)bcc free surfaces do not assist the phase transitions as nucleation sites upon heating/cooling in iron (Fe) thin slabs. In the present work, the three surfaces are denoted as “inactive” free surfaces. The phase transitions in Fe thin films with these “inactive” free surfaces have been studied using a classical molecular dynamics simulation and the Meyer–Entel potential. Our results show that shear deformation helps to activate the free surface as nucleation sites. The transition mechanisms are different in dependence on the surface orientation. In film with the (111)fcc free surface, two body-centered cubic (bcc) phases with different crystalline orientations nucleate at the free surface. In film with the (110)fcc surface, the nucleation sites are the intersections between the surfaces and stacking faults. In film with the (111)bcc surface, both heterogeneous nucleation at the free surface and homogeneous nucleation in the bulk material are observed. In addition, the transition pathways are analyzed. In all cases studied, the unstrained system is stable and no phase transition takes place. This work may be helpful to understand the mechanism of phase transition in nanoscale systems under external deformation.

Style APA, Harvard, Vancouver, ISO itp.

24

Downey, Jordan T. "The Reliability of Using Surface Data for Seriation". Advances in Archaeological Practice 5, nr 1 (luty 2017): 26–43. http://dx.doi.org/10.1017/aap.2016.2.

Pełny tekst źródła

Streszczenie:

ABSTRACTArchaeological sites are often dated through seriation analysis of artifacts found on the site's surface. This relative dating method remains common despite the widespread availability of absolute dating methods because it is fast and cost-effective compared to scientific dating methods such as radiocarbon dating. Surface seriation is especially important for regional survey studies that involve a large number of sites and little to no excavation. In this context it is important to ask: are surface assemblages as reliable an indicator of the age of a site as determined through excavation? This unique study addresses this question using data from seven sites in the Virú Valley on the north coast of Peru. Surface assemblages are compared with excavated ones using the G-test statistic. It is found that surface assemblages do not closely resemble excavated ones in a statistically significant sense. Nevertheless, the relative date of surface assemblages typically resembles the relative date of excavated assemblages. Caution is urged when dating surface assemblages purely through seriation because the surface may not actually be representative of excavated assemblages.

Style APA, Harvard, Vancouver, ISO itp.

25

Vice, Sue, i Dominic Williams. "“Non-sites of memory”". Alphaville: Journal of Film and Screen Media, nr 21 (5.08.2021): 35–54. http://dx.doi.org/10.33178/alpha.21.02.

Pełny tekst źródła

Streszczenie:

This article analyses some of the 30 hours of location footage excluded from Claude Lanzmann’s 1985 Holocaust documentary Shoah. Although there has been some analysis of the outtake material in Lanzmann’s archive which consists of eyewitness interviews, very little attention has been paid to the footage of landscape, urban and camp settings, from which we have drawn these examples of Polish sites. We argue that it is possible to discern the presence of a specifically spatial memory by considering this excluded material in a way that draws on its outtake status, that is, its form of 11-minute reels unaccompanied by eyewitness presence or voiceover. The filmic construction of spaces to suit Lanzmann’s concerns is revealed if we attend to this material in its unedited state, with its constituent repetitions and exclusions, as a spatial version of the director’s customary interest in the reincarnation of the past in the present.

Style APA, Harvard, Vancouver, ISO itp.

26

Qiao, Liang, Shu Jie Liu, Xiao Ying Hu, Li Li Wang i Dong Mei Bi. "Theoretical Investigation of Carbon Atom Adsorption and Diffusion on the Surfaces of Cu". Advanced Materials Research 1082 (grudzień 2014): 475–79. http://dx.doi.org/10.4028/www.scientific.net/amr.1082.475.

Pełny tekst źródła

Streszczenie:

The adsorption and diffusion of carbon atom on Cu (111) and (100) surfaces have been investigated based on first-principles density-functional theory. For Cu (111) surface, the hexagonal close-packed and face-centered cubic sites are the most stable sites with little energy difference in the adsorption energy. For Cu (100) surface, the hollow site is the most stable. There is charge transfer from Cu surface to the adsorbed carbon atom. Moreover, the diffusions of carbon atom on Cu surfaces have been investigated, and the results show that the diffusion of carbon atom prefers to happen on Cu (111) surface.

Style APA, Harvard, Vancouver, ISO itp.

27

Murashov, Vladimir V., i Eugene Demchuk. "Surface sites and unrelaxed surface energies of tetrahedral silica polymorphs and silicate". Surface Science 595, nr 1-3 (grudzień 2005): 6–19. http://dx.doi.org/10.1016/j.susc.2005.07.030.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

28

Coluccia, S., S. Lavagnino i L. Marchese. "The hydroxylated surface of MgO powders and the formation of surface sites". Materials Chemistry and Physics 18, nr 5-6 (styczeń 1988): 445–64. http://dx.doi.org/10.1016/0254-0584(88)90016-8.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

29

Bessason, Bjarni, i Sigurður Erlingsson. "Shear wave velocity in surface sediments". Jökull 61, nr 1 (15.12.2011): 51–64. http://dx.doi.org/10.33799/jokull2011.61.051.

Pełny tekst źródła

Streszczenie:

Surface sediments of different nature are common in Iceland. Natural soil sites and man-made fillings commonly serve as foundations for different types of structures. In Civil engineering work it is fundamental to know the geotechnical properties of these materials in the upper 20–30 m. A seismic method called Spectral Analysis of Surface Waves (SASW) has been used in recent decades in Iceland to measure and evaluate shear wave velocity at different natural sites as well as in man-made fillings. The method is fast and involves low cost equipment. It gives reliable results down to 20 m depth by using sledge as a seismic source and copes with both soft and stiff soil sites. Furthermore, the technique can be applied at coarse grained gravelly sites where it can be difficult to use borehole and penetration methods. We describe the methodology used in these projects and review all SASW measurements carried out in Iceland. The soil strata at all test sites are classified based on sieve analysis when possible. Natural sites and man-made fillings are kept separated. A database and an open web site are introduced where all the SASW results can be viewed and shear wave profiles for different soil types and unlike sites can be compared. The main aim with the database and the webpage is to give scientists and engineers access to this data and enable them to compare stiffness at different sites.

Style APA, Harvard, Vancouver, ISO itp.

30

Birang, Reza, Mohammad Tavakoli, Mohammad Shahabouei, Alireza Torabi, Ali Dargahi i Ahmad Soolari. "Investigation of Peri-Implant Bone Healing Using Autologous Plasma Rich in Growth Factors in the Canine Mandible After 12 Weeks: A Pilot Study". Open Dentistry Journal 5, nr 1 (4.11.2011): 168–73. http://dx.doi.org/10.2174/1874210601105010168.

Pełny tekst źródła

Streszczenie:

Introduction: Faster reconstruction of patients’ masticatory systems is the aim of modern dentistry. A number of studies have indicated that application of growth factors to the surface of a dental implant leads to accelerated and enhanced osseointegration. The objective of the present study was to investigate the effect of plasma rich in growth factors on peri-implant bone healing. Materials and Methods: For the purpose of this study, two healthy, mixed-breed canines were selected, and the premolars were extracted from both sides of the mandible. Three months after premolar removal, 12 implants, each 5 mm in diameter and 10 mm in length, were placed in osteotomy sites on both sides of the mandible. Prior to placement, plasma rich in growth factors was applied to the surfaces of six implants, while the other six were used without plasma rich in growth factors. The implants were removed after 12 weeks along with the bone surrounding the sites using a trephine bur. One mesiodistal section containing the surrounding bone from each implant block, 50 µm in diameter, was prepared for histologic and histomorphometric investigation with an optical microscope. Results: The sites with implants treated with plasma rich in growth factors showed more bone-to-implant contact compared to control sites. Also, higher values for bone trabecular thickness and bone maturity were recorded for the PRGF-treated sites than for the control sites. Conclusion: Application of plasma rich in growth factors to the surface of an implant may enhance the bone healing process as well as bone-to-implant contact, thereby helping to achieve faster osseointegration.

Style APA, Harvard, Vancouver, ISO itp.

31

Tsukahara, N., i J. Yoshinobu. "Potential Energy Surface of NO on Pt(997): Adsorbed States and Surface Diffusion". Advances in Physical Chemistry 2012 (26.10.2012): 1–9. http://dx.doi.org/10.1155/2012/571657.

Pełny tekst źródła

Streszczenie:

The potential energy surface (PES) of NO on Pt(997) has been elucidated: the adsorption states and diffusion processes of NO on Pt(997) at low coverage were investigated by using infrared reflection absorption spectroscopy (IRAS) and scanning tunneling microscopy (STM). When NO molecules adsorb on a surface at a low temperature (11 K), each molecule transiently migrates on the surface from the first impact point to a possible adsorption site. We found that there are four stable adsorption sites for NO on Pt(997): a bridge site of the upper step, an fcc- (or hcp-) hollow site of the terrace, an on-top site of the terrace, and an fcc-hollow site of the lower step. At higher temperatures above 45 K, NO molecules start to migrate thermally to more stable adsorption sites on a terrace, and they are finally trapped at the bridge sites of the step, which are the most stable among the four sites.

Style APA, Harvard, Vancouver, ISO itp.

32

Voitko, K. V., O. M. Bakalinska, Yu V. Goshovska, Yu I. Sementsov i M. T. Kartel. "Catalase-like properties of multilayer graphene oxides and their modified forms". Surface 12(27) (30.12.2020): 251–62. http://dx.doi.org/10.15407/surface.2020.12.251.

Pełny tekst źródła

Streszczenie:

The catalytic system, that mimets catalase enzyme such as “multilayer graphene oxide /peroxide molecule” in aqueous media was investigated. The main factors that influence on catalyst’s effectiveness were determining. The catalytic activity of as-synthesized multilayered graphene oxides, and their modified forms (oxidized and nitrogen doped) were investigated in the decomposition of hydrogen peroxides at room temperature and physiological pHs by measuring the volume of released gases. A phosphate buffer with a pH of 5 to 8 was chosen as the reaction medium. The original and modified samples were characterized using XPS, TPD-MS, Boehm titration analyses. The effect of surface chemistry on the catalytic reaction proceeding has been studied. It was found that catalysis on the graphene plane is determined by the presence of heteroatoms in their structure. The catalytic process takes place in the kinetic zone over the entire accessible surface of the samples. The active sites of the catalysts contain a large amount of both nitrogen and oxygen-containing functional groups. In addition, the surface of graphene oxide is hydrophilic, which enhances the catalytic reaction in an aqueous medium. It has been established that the rate of hydrogen peroxide decomposition by reduced graphene oxide samples is lower than for samples modified with oxygen and nitrogen. The catalase-like activity of graphene increases in alkaline pH up to 7.8. Studies have shown that samples of multilayer graphenes with a high content of functional groups can be an alternative to the catalase enzyme as a catalyst for the decomposition of hydrogen peroxide in physiological solutions.

Style APA, Harvard, Vancouver, ISO itp.

33

Bertinetti, Luca, Anna Tampieri, Elena Landi, V. Bolis, C. Busco i Gianmario Martra. "Surface Structure, Hydration and Cationic Sites of Nanohydroxyapatite". Key Engineering Materials 361-363 (listopad 2007): 87–90. http://dx.doi.org/10.4028/www.scientific.net/kem.361-363.87.

Pełny tekst źródła

Streszczenie:

In this work, we studied the surface/water interaction properties of a pure calcium hydroxyapatite (HA) and their modifications as a consequence of the partial Ca2+/Mg2+ (MHA) substitution by means of IR spectroscopy and microcalorimetry of adsorbed water. IR data indicated that water molecules in direct contact with the surface of HA are coordinated to surface cations and experience H-bond significantly stronger than in liquid water. The heats of adsorption associated to such interactions are very high, being twice-triple the heat of liquefaction of water. Interestingly, water experiences H-bond higher than in its bulk liquid state also in the second layer. Finally the entering in the material of Mg2+ ions was shown to significantly affect the affinity of the material toward water and the properties of its hydration layers.

Style APA, Harvard, Vancouver, ISO itp.

34

M. KUMAR, B.R.D. GUPTA, A.M. SHEKH, V. PANDEY i H. R. PATEL. "Assessment of surface radiation components at LASPEX sites". Journal of Agrometeorology 3, nr 1-2 (1.09.2001): 79–87. http://dx.doi.org/10.54386/jam.v3i1-2.392.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

35

Haegeman, W., i W. F. Van Impe. "Characterization of Disposal Sites from Surface Wave Measurements". Journal of Environmental and Engineering Geophysics 4, nr 1 (marzec 1999): 27–33. http://dx.doi.org/10.4133/jeeg4.1.27.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

36

Furukawa, Shinya. "Design of Surface Reaction Sites Using Intermetallic Compounds". Materia Japan 59, nr 7 (1.07.2020): 366–71. http://dx.doi.org/10.2320/materia.59.366.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

37

Zaheer, Farah, Serge H. Roy i Carlo J. De Luca. "Preferred sensor sites for surface EMG signal decomposition". Physiological Measurement 33, nr 2 (20.01.2012): 195–206. http://dx.doi.org/10.1088/0967-3334/33/2/195.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

38

Deskins, N. Aaron, Roger Rousseau i Michel Dupuis. "Distribution of Ti3+ Surface Sites in Reduced TiO2". Journal of Physical Chemistry C 115, nr 15 (25.03.2011): 7562–72. http://dx.doi.org/10.1021/jp2001139.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

39

Pfisterer, Jonas H. K., Yunchang Liang, Oliver Schneider i Aliaksandr S. Bandarenka. "Direct instrumental identification of catalytically active surface sites". Nature 549, nr 7670 (wrzesień 2017): 74–77. http://dx.doi.org/10.1038/nature23661.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

40

Martra, Gianmario, Elena Chiardola, Salvatore Coluccia, Leonardo Marchese, Maura Tomatis i Bice Fubini. "Reactive Sites at the Surface of Crocidolite Asbestos†". Langmuir 15, nr 18 (sierpień 1999): 5742–52. http://dx.doi.org/10.1021/la9814541.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

41

Medvedev, Dmitrii A., Alexandra A. Rybinskaya, Roman M. Kenzhin, Alexander M. Volodin i Alexander F. Bedilo. "Characterization of electron donor sites on Al2O3 surface". Physical Chemistry Chemical Physics 14, nr 8 (2012): 2587. http://dx.doi.org/10.1039/c2cp20863f.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

42

Wagenbach, D., M. Legrand, H. Fischer, F. Pichlmayer i E. W. Wolff. "Atmospheric near-surface nitrate at coastal Antarctic sites". Journal of Geophysical Research: Atmospheres 103, nr D9 (1.05.1998): 11007–20. http://dx.doi.org/10.1029/97jd03364.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

43

Gellman, Andrew J. "Heterocyclization sites on the sulfided palladium(111) surface". Journal of Physical Chemistry 96, nr 2 (styczeń 1992): 790–95. http://dx.doi.org/10.1021/j100181a049.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

44

Murashov, Vladimir. "Ab initio cluster calculations of silica surface sites". Journal of Molecular Structure 650, nr 1-3 (maj 2003): 141–57. http://dx.doi.org/10.1016/s0022-2860(03)00098-x.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

45

Rubio, F., J. Rubio i J. L. Oteo. "Distribution of active sites on E-glass surface". Journal of Materials Science Letters 11, nr 22 (1992): 1501–3. http://dx.doi.org/10.1007/bf00729272.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

46

Chandra, Anand, Kanayathu Koshy i Matakite Maata. "Surface ozone profiles at selected South Pacific sites". South Pacific Journal of Natural and Applied Sciences 32, nr 2 (2014): 47. http://dx.doi.org/10.1071/sp14008.

Pełny tekst źródła

Streszczenie:

Surface ozone profiles were studied at Fiji (18.1oS, 178.2oE), Samoa (14.3oS, 170.6oW), Tahiti (18.0oS, 149.0oW), and San Cristobal, Galapagos (0.9oS, 89.6oW) from 1997-2003. Surface ozone levels at these Pacific sites showed a wintertime maximum and a summertime minimum with the lowest mixing ratios occurring at Tahiti and Galapagos, while the highest mixing ratios occurred at Fiji. The seasonal trends at each site were found to be dependent on the varying photochemical sink strength and the changing transport regimes in each season. It was established that the reduced photochemical sink strength in winter was one of the major reasons for the observed increase in surface ozone levels at each site in that season. The presence of the South Pacific Convergence Zone particularly for the Western Pacific (Fiji, Samoa and Tahiti) is the other factor contributing to the observed seasonality and variability in surface ozone levels. The changing frequency of transport from the southern mid-latitude (from high altitudes) is the only transport regime at the boundary layer having the most significant influence on the surface ozone levels at these Pacific sites.

Style APA, Harvard, Vancouver, ISO itp.

47

Ibraheem, Farheen, Malik Zawwar Hussain i Akhlaq Ahmad Bhatti. "C¹ Positive Surface over Positive Scattered Data Sites". PLOS ONE 10, nr 6 (9.06.2015): e0120658. http://dx.doi.org/10.1371/journal.pone.0120658.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

48

Lee, J., M. Natarajan, V. C. Nashine, M. Socolich, T. Vo, W. P. Russ, S. J. Benkovic i R. Ranganathan. "Surface Sites for Engineering Allosteric Control in Proteins". Science 322, nr 5900 (17.10.2008): 438–42. http://dx.doi.org/10.1126/science.1159052.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

49

Pires, J. C. M., M. C. M. Alvim-Ferraz i F. G. Martins. "Surface ozone behaviour at rural sites in Portugal". Atmospheric Research 104-105 (luty 2012): 164–71. http://dx.doi.org/10.1016/j.atmosres.2011.10.001.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

50

Groszek, A. J. "Graphitic and polar surface sites in carbonaceous solids". Carbon 25, nr 6 (1987): 717–22. http://dx.doi.org/10.1016/0008-6223(87)90140-0.

Pełny tekst źródła

Style APA, Harvard, Vancouver, ISO itp.

Artykuły w czasopismach na temat „Surface sites”

Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych