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1. Space weathering simulations through controlled growth of iron nanoparticles on olivine

Author

Kohout, T., Čuda, J., Filip, J., Britt, D., Bradley, T., Tuček, J., Skála, R., Kletetschka, G., Kašlík, J., Malina, O., Šišková, K., and Zbořil, R.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Airless planetary bodies are directly exposed to space weathering. The main spectral effects of space weathering are darkening, reduction in intensity of silicate mineral absorption bands, and an increase in the spectral slope towards longer wavelengths (reddening). Production of nanophase metallic iron (npFe$^{0}$) during space weathering plays major role in these spectral changes. A laboratory procedure for the controlled production of npFe$^{0}$ in silicate mineral powders has been developed. The method is based on a two-step thermal treatment of low-iron olivine, first in ambient air and then in hydrogen atmosphere. Through this process, a series of olivine powder samples was prepared with varying amounts of npFe$^{0}$ in the 7-20 nm size range. A logarithmic trend is observed between amount of npFe$^{0}$ and darkening, reduction of 1 {\mu}m olivine absorption band, reddening, and 1 {\mu}m band width. Olivine with a population of physically larger npFe$^{0}$ particles follows spectral trends similar to other samples, except for the reddening trend. This is interpreted as the larger, ~40-50 nm sized, npFe$^{0}$ particles do not contribute to the spectral slope change as efficiently as the smaller npFe$^{0}$ fraction. A linear trend is observed between the amount of npFe$^{0}$ and 1 {\mu}m band center position, most likely caused by Fe$^{2+}$ disassociation from olivine structure into npFe$^{0}$ particles.

Published
2014
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2. Adaptation of sea turtles to climate warming: Will phenological responses be sufficient to counteract changes in reproductive output?

Author

Fuentes, Mariana M. P. B., Santos, Armando J. B., Abreu-Grobois, Alberto, Briseño-Dueñas, Raquel, Al-Khayat, Jassim, Hamza, Shafeeq, Saliba, Sally, Anderson, David, Rusenko, Kirt W., Mitchell, N. J., Gammon, Malindi, Bentley, Blair P., Beton, Damla, Booth, David T. B., Broderick, Annette C., Colman, Liliana P., Snape, Robin T. E., Calderón-Campuzano, María Fernanda, Cuevas, Eduardo, López-Castro, Melania Cecilia, Flores-Aguirre, Cynthia Dinorah, Méndez de la Cruz, Fausto, Segura-García, Y., Ruiz-García, A., Fossette, Sabrina, Gatto, Christopher R., Reina, Richard D., Girondot, Marc, Godfrey, Matthew, Guzmán-Hernández, Vicente, Hart, Catherine Edwina, Kaska, Yakup, Lara, Paulo Hunold, Marcovaldi, Maria Angela A. G. D., LeBlanc, Anne M., Rostal, David, Liles, Michael J., Wyneken, Jeanette, Lolavar, Alexandra, Williamson, Sean A., Manoharakrishnan, Muralidharan, Pusapati, Chandana, Chatting, Mark, Mohd Salleh, Sarahaizad, Patricio, Ana Rita, Regalla, A., Restrepo, Jaime, García, R., Santidrián-Tomillo, Pilar, Sezgin, Çisem, Shanker, Kartik, Tapilatu, Ricardo F., Turkozan, Oguz, Valverde, Roldán A., Williams, Kristina, Yilmaz, Can, Tolen, Nicholas, Nel, Ronel, Tucek, J., Legouvello, Diane, Rivas, Marga L., Gaspar, Cécile, Touron, M., Genet, Q., Salmon, Michael, Araujo, M. R., Freire, Jordana B., Castheloge, Vinicius D., Jesus, Paulo Roberto, Ferreira, Paulo D., Paladino, Frank V., Montero-Flores, D., Sozbilen, Doğan, Monsinjon, Jonathan R., Fuentes, Mariana M. P. B., Santos, Armando J. B., Abreu-Grobois, Alberto, Briseño-Dueñas, Raquel, Al-Khayat, Jassim, Hamza, Shafeeq, Saliba, Sally, Anderson, David, Rusenko, Kirt W., Mitchell, N. J., Gammon, Malindi, Bentley, Blair P., Beton, Damla, Booth, David T. B., Broderick, Annette C., Colman, Liliana P., Snape, Robin T. E., Calderón-Campuzano, María Fernanda, Cuevas, Eduardo, López-Castro, Melania Cecilia, Flores-Aguirre, Cynthia Dinorah, Méndez de la Cruz, Fausto, Segura-García, Y., Ruiz-García, A., Fossette, Sabrina, Gatto, Christopher R., Reina, Richard D., Girondot, Marc, Godfrey, Matthew, Guzmán-Hernández, Vicente, Hart, Catherine Edwina, Kaska, Yakup, Lara, Paulo Hunold, Marcovaldi, Maria Angela A. G. D., LeBlanc, Anne M., Rostal, David, Liles, Michael J., Wyneken, Jeanette, Lolavar, Alexandra, Williamson, Sean A., Manoharakrishnan, Muralidharan, Pusapati, Chandana, Chatting, Mark, Mohd Salleh, Sarahaizad, Patricio, Ana Rita, Regalla, A., Restrepo, Jaime, García, R., Santidrián-Tomillo, Pilar, Sezgin, Çisem, Shanker, Kartik, Tapilatu, Ricardo F., Turkozan, Oguz, Valverde, Roldán A., Williams, Kristina, Yilmaz, Can, Tolen, Nicholas, Nel, Ronel, Tucek, J., Legouvello, Diane, Rivas, Marga L., Gaspar, Cécile, Touron, M., Genet, Q., Salmon, Michael, Araujo, M. R., Freire, Jordana B., Castheloge, Vinicius D., Jesus, Paulo Roberto, Ferreira, Paulo D., Paladino, Frank V., Montero-Flores, D., Sozbilen, Doğan, and Monsinjon, Jonathan R.

Abstract

Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a “middle of the road” scenario (SSP2-4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26–43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present-day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from −20 to −191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.

Published
2024

3. Adaptation of sea turtles to climate warming: Will phenological responses be sufficient to counteract changes in reproductive output?

Author

Fuentes, M. M. P. B., Santos, A. J. B., Abreu‐grobois, A., Briseño‐dueñas, R., Al‐khayat, J., Hamza, Samir, Saliba, S., Anderson, D., Rusenko, K. W., Mitchell, N. J., Gammon, M., Bentley, B. P., Beton, D., Booth, D. T. B., Broderick, A. C., Colman, L. P., Snape, R. T. E., Calderon‐campuzano, M. F., Cuevas, E., Lopez‐castro, M. C., Flores‐aguirre, C. D., Mendez de la cruz, F., Segura‐garcia, Y., Ruiz‐garcia, A., Fossette, S., Gatto, C. R., Reina, R. D., Girondot, M., Godfrey, M., Guzman‐hernandez, V., Hart, C. E., Kaska, Y., Lara, P. H., Marcovaldi, M. A. G. D., Leblanc, A. M., Rostal, D., Liles, M. J., Wyneken, J., Lolavar, A., Williamson, S. A., Manoharakrishnan, M., Pusapati, C., Chatting, M., Mohd salleh, S., Patricio, A. R., Regalla, A., Restrepo, J., Garcia, R., Santidrián tomillo, P., Sezgin, C., Shanker, K., Tapilatu, F., Turkozan, O., Valverde, R. A., Williams, K., Yilmaz, C., Tolen, N., Nel, R., Tucek, J., Legouvello, D., Rivas, M. L., Gaspar, C., Touron, M., Genet, Q., Salmon, M., Araujo, M. R., Freire, J. B., Castheloge, V. D., Jesus, P. R., Ferreira, P. D., Paladino, F. V., Montero‐flores, D., Sozbilen, D., Monsinjon, Jonathan, Fuentes, M. M. P. B., Santos, A. J. B., Abreu‐grobois, A., Briseño‐dueñas, R., Al‐khayat, J., Hamza, Samir, Saliba, S., Anderson, D., Rusenko, K. W., Mitchell, N. J., Gammon, M., Bentley, B. P., Beton, D., Booth, D. T. B., Broderick, A. C., Colman, L. P., Snape, R. T. E., Calderon‐campuzano, M. F., Cuevas, E., Lopez‐castro, M. C., Flores‐aguirre, C. D., Mendez de la cruz, F., Segura‐garcia, Y., Ruiz‐garcia, A., Fossette, S., Gatto, C. R., Reina, R. D., Girondot, M., Godfrey, M., Guzman‐hernandez, V., Hart, C. E., Kaska, Y., Lara, P. H., Marcovaldi, M. A. G. D., Leblanc, A. M., Rostal, D., Liles, M. J., Wyneken, J., Lolavar, A., Williamson, S. A., Manoharakrishnan, M., Pusapati, C., Chatting, M., Mohd salleh, S., Patricio, A. R., Regalla, A., Restrepo, J., Garcia, R., Santidrián tomillo, P., Sezgin, C., Shanker, K., Tapilatu, F., Turkozan, O., Valverde, R. A., Williams, K., Yilmaz, C., Tolen, N., Nel, R., Tucek, J., Legouvello, D., Rivas, M. L., Gaspar, C., Touron, M., Genet, Q., Salmon, M., Araujo, M. R., Freire, J. B., Castheloge, V. D., Jesus, P. R., Ferreira, P. D., Paladino, F. V., Montero‐flores, D., Sozbilen, D., and Monsinjon, Jonathan

Abstract

Sea turtles are vulnerable to climate change since their reproductive output is influenced by incubating temperatures, with warmer temperatures causing lower hatching success and increased feminization of embryos. Their ability to cope with projected increases in ambient temperatures will depend on their capacity to adapt to shifts in climatic regimes. Here, we assessed the extent to which phenological shifts could mitigate impacts from increases in ambient temperatures (from 1.5 to 3°C in air temperatures and from 1.4 to 2.3°C in sea surface temperatures by 2100 at our sites) on four species of sea turtles, under a “middle of the road” scenario (SSP2‐4.5). Sand temperatures at sea turtle nesting sites are projected to increase from 0.58 to 4.17°C by 2100 and expected shifts in nesting of 26–43 days earlier will not be sufficient to maintain current incubation temperatures at 7 (29%) of our sites, hatching success rates at 10 (42%) of our sites, with current trends in hatchling sex ratio being able to be maintained at half of the sites. We also calculated the phenological shifts that would be required (both backward for an earlier shift in nesting and forward for a later shift) to keep up with present‐day incubation temperatures, hatching success rates, and sex ratios. The required shifts backward in nesting for incubation temperatures ranged from −20 to −191 days, whereas the required shifts forward ranged from +54 to +180 days. However, for half of the sites, no matter the shift the median incubation temperature will always be warmer than the 75th percentile of current ranges. Given that phenological shifts will not be able to ameliorate predicted changes in temperature, hatching success and sex ratio at most sites, turtles may need to use other adaptive responses and/or there is the need to enhance sea turtle resilience to climate warming.

Published
2023
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8. Forest Fire Vulnerability Analysis

Author

Tuček, J., Majlingová, A., Střelcová, Katarína, editor, Mátyás, Csaba, editor, Kleidon, Axel, editor, Lapin, Milan, editor, Matejka, František, editor, Blaženec, Miroslav, editor, Škvarenina, Jaroslav, editor, and Holécy, Ján, editor

Published
2009
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16. world

Author

Monsinjon, JR, Wyneken, J, Rusenko, K, Lopez-Mendilaharsu, M, Lara, P, Santos, A, dei Marcovaldi, MAG, Fuentes, MMPB, Kaska, Y, Tucek, J, Nel, R, William, KL, LeBlanc, AM, Rostal, D, Guillon, JM, and Girondot, M

Subjects
Climate change, Phenotypic plasticity, Phenology, Hatching success, Sex, Caretta caretta, ratio, Embryonic development, Incubation, Thermal tolerance, Reptile
Abstract

Phenological shifts, by initiating reproductive events earlier, in response to advanced seasonal warming is one of the most striking effects currently observed in wild populations. For sea turtles, phenological adjustment to warming conditions could be the most effective short-term adaptation option against climate change. We calculated future phenological changes required in seven important loggerhead (Caretta caretta) nesting populations to continue achieving a high hatching success and a sex ratio that lies within current ranges. Considering temperature-mediated phenological changes, we found that most populations (six out of seven) will not be able to keep pace with a warming climate. Under an optimistic climate warming scenario (RCP4.5), these populations will face a climatic debt, that is, a difference between required and expected phenological changes, and warming will substantially reduce hatching success and induce a feminization of hatchlings, which may jeopardize their reproductive sustainability. Our approach offers the possibility to quantify the efficiency of phenological shifts in oviparous reptiles by considering physiological, developmental and phenological processes. C1 [Monsinjon, Jonathan R.; Guillon, Jean-Michel; Girondot, Marc] Univ Paris Saclay, Univ Paris Sud, Lab Ecol Systemat Evolut, CNRS,AgroParisTech, F-91405 Orsay, France. [Wyneken, Jeanette] Florida Atlantic Univ, Dept Biol Sci, Boca Raton, FL 33431 USA. [Rusenko, Kirt] Gumbo Limbo Nat Ctr, 1801 N Ocean Blvd, Boca Raton, FL 33432 USA. [Lopez-Mendilaharsu, Milagros; Lara, Paulo; Santos, Alexsandro; dei Marcovaldi, Maria A. G.] Fundacao Pro Tamar, Rua Rubens Guelli,134 Sala 307, Salvador, BA, Brazil. [Fuentes, Mariana M. P. B.] Florida State Univ, Dept Earth Ocean & Atmospher Sci, Marine Turtle Res Ecol & Conservat Grp, North Woodward Ave, Tallahassee, FL 32306 USA. [Kaska, Yakup] Pamukkale Univ, Sea Turtle Res Ctr DEKAMER, Denizli, Turkey. [Tucek, Jenny; Nel, Ronel] Nelson Mandela Univ, Dept Zool, ZA-6031 Port Elizabeth, South Africa. [William, Kristina L.] Caretta Res Project, POB 9841, Savannah, GA 31412 USA. [LeBlanc, Anne-Marie; Rostal, David] Georgia Southern Univ, Dept Biol, Statesboro, GA 30460 USA.

Published
2019

18. Forest decision support systems for the analysis of ecosystem services provisioning at the landscape scale under global climate and market change scenarios

Author

Nordström, E.-M., Nieuwenhuis, M., Başkent, E., Biber, P., Black, K., Borges, J.G., Bugalho, M., Corradini, G., Corrigan, E., Eriksson, L., Felton, A., Forsell, N., Hengeveld, G., Hoogstra-Klein, M., Korosuo, A., Lindbladh, M., Lodin, I., Lundholm, A., Marto, M., Masiero, M., Mozgeris, G., Pettenella, D., Poschenrieder, W., Sedmak, R., Tucek, J., Zoccatelli, D., Nordström, E.-M., Nieuwenhuis, M., Başkent, E., Biber, P., Black, K., Borges, J.G., Bugalho, M., Corradini, G., Corrigan, E., Eriksson, L., Felton, A., Forsell, N., Hengeveld, G., Hoogstra-Klein, M., Korosuo, A., Lindbladh, M., Lodin, I., Lundholm, A., Marto, M., Masiero, M., Mozgeris, G., Pettenella, D., Poschenrieder, W., Sedmak, R., Tucek, J., and Zoccatelli, D.

Abstract

Sustainable forest management is driving the development of forest decision support systems (DSSs) to include models and methods concerned with climate change, biodiversity and various ecosystem services (ESs). The future development of forest landscapes is very much dependent on how forest owners act and what goes on in the wider world; thus, models are needed that incorporate these aspects. The objective of this study is to assess how nine European state-of-the-art forest DSSs cope with these issues. The assessment focuses on the ability of these DSSs to generate landscape-level scenarios to explore the output of current and alternative forest management models (FMMs) in terms of a range of ESs and the robustness of these FMMs in the face of increased risks and uncertainty. Results show that all DSSs assessed in this study can be used to quantify the impacts of both stand- and landscape-level FMMs on the provision of a range of ESs over a typical planning horizon. DSSs can be used to assess how timber price trends may impact that provision over time. The inclusion of forest owner behavior as reflected by the adoption of specific FMMs seems to be also in the reach of all DSSs. Nevertheless, some DSSs need more data and development of models to estimate the impacts of climate change on biomass production and other ESs. Spatial analysis functionality needs to be further developed for a more accurate assessment of the landscape-level output of ESs from both current and alternative FMMs.

Published
2019

21. Substitution effects of barium and calcium on magnetic properties of AxSr1-x(Fe0.5Ru0.5)O3 double perovskites (x=0.05, A=Ba,Ca).

Author

Nomura, K., Zboril, R., Tucek, J., Kosaka, W., Ohkoshi, S., and Felner, I.

Subjects
TRANSMISSION electron microscopy, PEROVSKITE, MAGNETIC measurements, HYSTERESIS loop, SCANNING electron microscopy, MAGNETIC fields, CRYSTAL growth, CRYSTAL grain boundaries
Abstract

AxSr1-x(Fe0.5Ru0.5)O3 double perovskites (x=0.05 and A=Ba,Ca) were prepared by a sol-gel method and an effect of the cation substitution at the A site of the crystal structure of SrFe0.5Ru0.5O3 on their magnetic properties was monitored by x-ray diffraction (XRD), magnetic measurements, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and temperature-dependent and in-field 57Fe Mössbauer spectroscopy. Both Ca- and Ba-substituted samples reveal the orthorhombic structure similar to the undoped perovskite; however, the cell volume changes with the substituting ion radius. TEM and SEM micrographs manifest agglomerated nanocrystalline samples with particle sizes of about 20–60, 15–50, and 40–70 nm for the undoped, Ba-doped, and Ca-doped perovskites, respectively. Generally, the magnetic regime of both substituted and undoped perovskites can be described by a spin-glass behavior caused by a spin frustration. Among other factors, this is manifested by a nonsaturation of the hysteresis loops even at a high field of 50 kOe, by a low-temperature divergence of the zero-field-cooled and field-cooled magnetization curves, and by a cusp in the zero-field-cooled magnetization curve. The low-temperature spin-glass state is also supported by the in-field Mössbauer spectra, recorded on these systems. The isomer shift parameters, extracted from the Mössbauer spectra, confirm a high-spin iron(III) state with S=5/2. In contrast to the undoped and Ba-doped samples, the narrower distribution of the hyperfine magnetic fields, observed in the Ca-doped perovskite can be ascribed to the larger particles. Compared to the undoped sample, the field of maximum probability is higher in the Ca-substituted perovskite while it is reduced in the Ba-doped sample because of the effects of the chemical compression and expansion, respectively. In addition, the Ca-doped sample exhibits more negative Weiss temperature (Θ=-105 K) than that found for the Ba-substituted perovskite (Θ=-49 K), implying that doping with Ca at Sr sites of SrFe0.5Ru0.5O3 perovskite structure provokes strengthening of antiferromagnetic interactions at the expense of the other ones. Furthermore, both substituted samples reveal significantly reduced coercive fields in the hysteresis loops recorded at 5 K, probably as a result of decreasing magnetocrystalline anisotropy. This is an indirect evidence of the essential influence of the substitution on the crystal growth of the synthesized particles. The role of SrRuO3 and SrFeO3 compounds, which have been detected in magnetic and Mössbauer measurements as admixtures, is discussed. [ABSTRACT FROM AUTHOR]

Published
2007
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22. Substitution effects of barium and calcium on magnetic properties of [A.sub.x][Sr.sub.1-x]([Fe.sub.0.5][Ru.sub.0.5])[O.sub.3] double perovskites (x=0.05, A=Ba, Ca)

Author

Nomura, K., Zboril, R., Tucek, J., Kosaka, W., Ohkoshi, S., and Felner, I.

Subjects
Perovskite -- Structure, Perovskite -- Chemical properties, Barium compounds -- Structure, Barium compounds -- Chemical properties, Crystals -- Structure, Crystals -- Research, Physics
Abstract

[A.sub.x][Sr.sub.1-x]([Fe.sub.0.5][Ru.sub.0.5])[O.sub.3] double perovskites (x = 0.05, A = Ba, Ca) are prepared by a sol-gel method and the effect of cation substitution at the A site of the crystal structure of Sr[Fe.sub.0.5][Ru.sub.0.5][O.sub.3] on their magnetic properties are examined. The magnetic properties of these systems are described, where the general spin-glass behavior is affected by the chemical pressure and finite-size effects due to cation substitution and sample nanocrystallinity.

Published
2007

24. Low energy, ion-induced electron and ion emission from stainless steel: The effect of oxygen...

Author

Walton, S. G. and Tucek, J. C.

Subjects
*ELECTRON emission, *IONS, *STAINLESS steel
Abstract

Presents information on a study which determined the absolute yields of electrons and negative ions resulting from positive ions compacting stainless steel as a function of impact energy for clean and oxygen-covered surfaces. Experimental method; Results and discussion; Conclusions.

Published
1999
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25. Electrostatically stabilized hybrids of carbon and maghemite nanoparticles: electrochemical study and application

Author

Baratella, D., primary, Magro, M., additional, Jakubec, P., additional, Bonaiuto, E., additional, de Almeida Roger, J., additional, Gerotto, E., additional, Zoppellaro, G., additional, Tucek, J., additional, Safarova, K. C., additional, Zbořil, R., additional, Cecconello, A., additional, Willner, I., additional, Santagata, S., additional, Sambo, P., additional, and Vianello, F., additional

Published
2017
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28. Synthesis and Characterization of gamma-Fe2O3/Carbon Hybrids and Their Application in Removal of Hexavalent Chromium Ions from Aqueous Solutions

Author

Baikousi, M., Bourlinos, A. B., Douvalis, A., Bakas, T., Anagnostopoulos, D. F., Tucek, J., Safarova, K., Zboril, R., and Karakassides, M. A.

Subjects
magnetic nanoparticles, waste-water, adsorption, maghemite nanoparticles, mcm-48 silica, iron-oxide, surface, activated carbon, ordered mesoporous carbon, transition-metal
Abstract

Magnetic Fe2O3/carbon hybrids were prepared in a two-step process. First, acetic acid vapor interacted with iron cations dispersed on the surface of a nanocasted ordered mesoporous carbon (CMK-3). In the second step, the primarily created iron acetate species underwent pyrolysis and transformed to magnetic iron oxide nanoparticles. X-ray diffraction, Fourier-transform infrared, and Raman spectroscopies were used for the chemical and structural characterization of the hybrids, while surface area measurements, thermal analysis, and transmission electron microscopy were employed to determine their physical, surface, and textural properties. These results revealed the preservation of the host carbon structure, which was homogenously and controllably loaded (up to 27 wt %) with nanosized (ca. 20 nm) iron oxides inside the mesoporous system. Mossbauer spectroscopy and magnetic measurements at low temperatures confirmed the formation of gamma-Fe2O3 nanoparticles exhibiting superparamagnetic behavior. The kinetic studies showed a rapid removal of Cr(VI) ions from the aqueous solutions in the presence of these magnetic mesoporous hybrids and a considerably increased adsorption capacity per unit mass of sorbent in comparison to that of pristine CMK-3 carbon. The results also indicate highly pH-dependent sorption efficiency of the hybrids, whereas their kinetics was described by a pseudo-second-order kinetic model. Taking into account the simplicity of the synthetic procedure and possibility of magnetic separation of hybrids with immobilized pollutant, the developed mesoporous nanomaterials have quite real potential for applications in water treatment technologies. Langmuir

Published
2012

29. A facile synthetic route toward air-stable magnetic nanoalloys with Fe-Ni/Fe-Co core and iron oxide shell

Author

Douvalis, A. P., Zboril, R., Bourlinos, A. B., Tucek, J., Spyridi, S., and Bakas, T.

Subjects
Borohydride, ferric hydroxide, iron oxide, synthesis, oxidation, Iron, Mossbauer spectroscopy, magnetic nanoparticle, magnetic field, reduction, Borohydrides, Iron oxides, Magnetization, nickel, X ray fluorescence, alloy, Magnetization measurements, Iron alloys, Ferrihydrites, Ferrihydrite, chemical composition, Shells (structures), Nanomagnetics, degradation, Core-shell, Molybdenum, X ray powder diffraction, article, Superparamagnetism, particle size, cobalt, Organic solvents, priority journal, substitution reaction, Magnetic fields, Synthesis (chemical), Magnetic nanoparticles, sodium derivative, chemical structure, Nanoparticles, room temperature, Transmission electron microscopy, Chemical modification
Abstract

Air-stable bimetallic spherically shaped Fe-Ni and Fe-Co magnetic nanoparticles (MNPs), having an average size of 15 nm and core-shell structure, were synthesized by a simple wet chemical method under ambient conditions. For the first time, sodium borohydride reduction method, commonly applied for the syntheses of metal nanoparticles, was used for the preparation of well-defined Fe-Ni and Fe- Co nanoalloys, avoiding exploitation of any organic solvent. This approach allows a large scale production of nanoparticles specifically stabilized by an iron oxyhydroxide shell without a need of secondary functionalization. Transmission electron microscopy, X-ray powder diffraction, X-ray fluorescence, magnetization, and M?ssbauer data demonstrate a core- shell nature of the as-synthesized nanoparticles. The nanoparticle core is of metallic origin and is inhomogeneous at the atomic level, consisting of iron-rich and iron-poor alloy phases. The composition of the shell is close to the ferrihydrite and its role lies in prevention of oxidation-induced degradation of nanoparticle properties. The core is ferromagnetic at and below room temperature, experiencing superparamagnetic relaxation effects due to a reduced size of nanoparticles, whereas the shell is completely superparamagnetic at 300 K and magnetically orders below?25 K. Both developed types of magnetic nanoalloys exhibit a strong magnetic response under applied magnetic fields with a high magnetization values achievable at relatively low applied magnetic fields. Beside this, the highly biocompatible chemical composition of the nanoparticle shell and ability of its chemical modification by substitution or addition of other ions or molecules further empower the application potential of these MNPs, especially in the field of biomedicine. © Springer Science+Business Media B.V. 2012. Journal of Nanoparticle Research

Published
2012

30. Micro–mesoporous iron oxides with record efficiency for the decomposition of hydrogen peroxide: morphology driven catalysis for the degradation of organic contaminants

Author

Datta, K. J., primary, Gawande, M. B., additional, Datta, K. K. R., additional, Ranc, V., additional, Pechousek, J., additional, Krizek, M., additional, Tucek, J., additional, Kale, R., additional, Pospisil, P., additional, Varma, R. S., additional, Asefa, T., additional, Zoppellaro, G., additional, and Zboril, R., additional

Published
2016
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31. How Sensitive Are Ecosystem Services in European Forest Landscapes to Silvicultural Treatment?

Author

Biber, P., Borges, J.G., Moshammer, R., Barreiro, S., Botequim, B., Brodrechtová, Y., Brukas, V., Chirici, G., Cordero-Debets, R., Corrigan, E., Eriksson, L.O., Favero, M., Galev, E., Garcia-Gonzalo, J., Hengeveld, G.M., Kavaliauskas, M., Marchetti, M., Marques, S., Mozgeris, G., Navrátil, R., Nieuwenhuis, M., Orazio, C., Paligorov, I., Pettenella, D., Sedmák, R., Smrecek, R., Stanislovaitis, A., Tomé, M., Trubins, R., Tucek, J., Vizzarri, M., Wallin, I., Pretzsch, H., Sallnäs, O., Biber, P., Borges, J.G., Moshammer, R., Barreiro, S., Botequim, B., Brodrechtová, Y., Brukas, V., Chirici, G., Cordero-Debets, R., Corrigan, E., Eriksson, L.O., Favero, M., Galev, E., Garcia-Gonzalo, J., Hengeveld, G.M., Kavaliauskas, M., Marchetti, M., Marques, S., Mozgeris, G., Navrátil, R., Nieuwenhuis, M., Orazio, C., Paligorov, I., Pettenella, D., Sedmák, R., Smrecek, R., Stanislovaitis, A., Tomé, M., Trubins, R., Tucek, J., Vizzarri, M., Wallin, I., Pretzsch, H., and Sallnäs, O.

Abstract

While sustainable forestry in Europe is characterized by the provision of a multitude of forest ecosystem services, there exists no comprehensive study that scrutinizes their sensitivity to forest management on a pan-European scale, so far. We compile scenario runs from regionally tailored forest growth models and Decision Support Systems (DSS) from 20 case studies throughout Europe and analyze whether the ecosystem service provision depends on management intensity and other co-variables, comprising regional affiliation, social environment, and tree species composition. The simulation runs provide information about the case-specifically most important ecosystem services in terms of appropriate indicators. We found a strong positive correlation between management intensity and wood production, but only weak correlation with protective and socioeconomic forest functions. Interestingly, depending on the forest region, we found that biodiversity can react in both ways, positively and negatively, to increased management intensity. Thus, it may be in tradeoff or in synergy with wood production and forest resource maintenance. The covariables species composition and social environment are of punctual interest only, while the affiliation to a certain region often makes an important difference in terms of an ecosystem service’s treatment sensitivity.

Published
2015

35. Synthesis and properties of core-shell fluorescent hybrids with distinct morphologies based on carbon dots

Author

Markova, Z., Bourlinos, A. B., Safarova, K., Polakova, K., Tucek, J., Medrik, I., Siskova, K., Petr, J., Krysmann, Marta, Giannelis, E. P., Zboril, R., Markova, Z., Bourlinos, A. B., Safarova, K., Polakova, K., Tucek, J., Medrik, I., Siskova, K., Petr, J., Krysmann, Marta, Giannelis, E. P., and Zboril, R.

Abstract

top Fluorescent core–shell nanohybrids with the shells derived from carbon dots and cores differing in the chemical nature and morphology were synthesized. Hybrid nanoparticles combine fluorescence with other functionalities such as magnetic response on a single platform. These hybrids can be used in various bioapplications as demonstrated with labeling of stem cells.

Published
2012

44. Vacuum tube amplifiers

Author

Qiu, J.X., primary, Levush, B., additional, Pasour, J., additional, Katz, A., additional, Armstrong, C.M., additional, Whaley, D.R., additional, Tucek, J., additional, Kreischer, K., additional, and Gallagher, D., additional

Published
2009
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