Characterizing the Environmental Availability of Trace Metals in Savannah River Site Soils

An eight step sequential extraction technique was used to characterize the environmental availability of trace metals from background and waste site soil samples collected from the US Department of Energy's Savannah River Site (SRS)

Cell Imaging with Fluorescent Bi-Metallic Nanoparticles

Last decades various imaging techniques have been applied in biological and biomedical research, such as magnetic resonance imaging, different types of tomography, fluorescence/bioluminescence, ultrasound, as well as multimodality approaches. Fluorescence imaging, especially in combination with nanoscale materials, is a very prospective tool for experiments in vivo and clinical applications due to its high temporal and spatial resolutions. Fluorescent nanoparticles (NPs), having ability to interact with biomolecules both on the surface of and inside the cells, may revolutionize the cell imaging approaches for diagnostics and therapy. In our investigation we report about new method of cell imaging with fluorescent bi-metallic NPs synthesized by chemical reduction of the relevant ions. As the model of living organism, the cells of yeast Hansenula polymorpha were used. All NPs in minimal concentration (up to 0.05 mM) was proved to be non-toxic for yeast cells. The NPs and NPs-modified cells were characterized with the methods of UV-VIS spectroscopy, scanning electron microscopy, atom force microscopy, transmission electron microscopy and fluorescence microscopy. The bimetallic NPs, possessing the stable fluorescence in solution and inside the cells, allow to observe the phenomenon of NPs transferring from parental to daughter cells through at least three generations followed by releasing from the modified cells. The fluorescent NPs synthesized being small, non-toxic and fluorescent was shown to be perspective tool for cell imaging

'Cold' crystallization in nanostructurized 80GeSe 2 -20Ga 2 Se 3 glass

International audience'Cold' crystallization in 80GeSe 2-20Ga 2 Se 3 chalcogenide glass nanostructurized due to thermal annealing at 380°C for 10, 25, 50, 80, and 100 h are probed with X-ray diffraction, atomic force, and scanning electron microscopy, as well as positron annihilation spectroscopy performed in positron annihilation lifetime and Doppler broadening of annihilation line modes. It is shown that changes in defect-related component in the fit of experimental positron lifetime spectra for nanocrystallized glasses testify in favor of structural fragmentation of larger free-volume entities into smaller ones. Nanocrystallites of Ga 2 Se 3 and/or GeGa 4 Se 8 phases and prevalent GeSe 2 phase extracted mainly at the surface of thermally treated samples with preceding nucleation and void agglomeration in the initial stage of annealing are characteristic features of cold crystallization

In-Situ Kd Values nad Geochemical Behavior for Inorganic and Organic Constituents of Concern at the TNX Outfall Delta REC.EIVED

in the bulk utter unncaling in forming gas but not after high tempemture ( 1100"C) anneaIs in Ar. The presence of hydrogen dmmatical[y incrcascs the broad PL band centered in the near-infmred after tinncaling Lit1100"C but htis almost no effect on the PL spectral distribution. Hydrogen is found to sclccti~cly trap in the region where Si nanocrystais are formed, consistent with a model of H ptissivatin: surfucc states tit the Si/SiO: interface that leads to enhanced PL. The thermal stabiIity of the tmppul H and the PL yield observed ufter a high temperature anneal have been studied. The hydrogen concentration and PL yield are unchanged for subsequent anneals up to 400"C. However, ubovc -IO(YCthe PL decreases tind a more complicated H chemistry is evident. Similar concentmtions of H or D ure tmpped after annealing in HJ or Dj forming gas; however, no differences in the PL yield or spcctrtil distribution tire observed, indicating that the electronic transitions resulting in luminescence are not dependent on the moss of the hydrogen species

Superhydrophobic/superhydrophilic switching on the surface of ZnO microstructures caused by UV irradiation and argon ion etching process

ZnO microstructures of different morphology were investigated using the water contact angle (WCA) analysis. The as-grown ZnO microstructures were found to exhibit pure hydrophobic behavior, which is enhanced with the increase of their surface area. The most hydrophobic structures (WCA = 157°) were found to be the complex microoctapods, containing both the macro-and nanoscale features.Микроструктуры ZnO различной морфологии были исследованы с помощью анализа угла контакта воды (УКВ). Было установлено, что выращенные непосредственно перед измерением микроструктуры ZnO проявляют гидрофобные свойства, которые усиливаются с увеличением площади их поверхности. Наилучшими гидрофобными свойствами (УКВ = 157°) владели микрооктаподы с микро- и наноразмерными составляющими структуры.Мікроструктури ZnO різної морфології були досліджені за допомогою аналізу кута контакту води (ККВ). Було встановлено, що вирощені безпосередньо перед вимірюванням мікроструктури ZnO проявляють гідрофобні властивості, які посилюються зі збільшенням площі їхньої поверхні. Найкращими гідрофобними властивостями (ККВ = 157°) володіли мікрооктаподи з мікро- і нанорозмірними складовими структури

Superhydrophobic/superhydrophilic switching on the surface of ZnO microstructures caused by UV irradiation and argon ion etching process

The superhydrophobic materials can be used in manufacturing of the devices and things with the self-cleaning properties (such as solar panels, textiles and building materials, such as glass, tile etc.), coatings with a low friction (such as vehicles), anti-corrosion, anti-icing and antisticking coatings, lab-on-chip devices, drug delivery etc

Потрійні системи Lu-V-{Ge, Sn}

The isothermal sections of the phase diagrams of the Lu–V–Ge and Lu-V-Sn ternary systems were constructed at 870 K over the whole concentration range using X-ray diffraction and EPM analyses. In the Lu-V-Ge system a formation of the substitutional solid solution Lu5Ge3-xVx based on the Lu5Ge3binary compound (Mn5Si3 structure type) was found up to 6 at. % V. Insertion of the V atoms in the structure of the LuGe2 binary germanide (ZrSi2structure type, up to 5 aт. % V) results in the formation of the LuV0,15Ge2 ternary phase (CeNiSi2 structure type, space group Cmcm, a=0.40210(4),b=1.5661(1), c=0.38876(3) nm), which corresponds to the limit composition of the interstitial solid solution LuVxGe2. The interaction between the elements in the Lu-V-Sn system results in the formation of one ternary compound LuV6Sn6 (SmMn6Sn6-type, space group P6/mmm, a=0.5503(2), c=0.9171(4) nm) at investigated temperature.Ізотермічні перерізи діаграм стану потрійних систем Lu–V–Ge і Lu-V-Sn побудовані за температури 870 K в повному концентраційному інтервалі методами рентгенофазового, рентгеноструктурного і мікроструктурного аналізів. В системі Lu-V-Ge на основі бінарної сполуки Lu5Ge3(структурний тип Mn5Si3) встановлено утворення твердого розчину заміщення Lu5Ge3-xVx до вмісту 6 aт. % V. Включення атомів V в структуру бінарного германіду LuGe2 (структурний тип ZrSi2, до вмісту 5 aт. % V) приводить до утворення тернарної фази LuV0,15Ge2 (структурний тип CeNiSi2, просторова група Cmcm, a=0,40210(4), b=1,5661(1), c=0,38876(3) нм), яка відповідає граничному складу твердого розчину включення LuVxGe2. Взаємодія компонентів у системі Lu-V-Sn за температури дослідження характеризується утворенням тернарної сполуки LuV6Sn6(структурний тип SmMn6Sn6, просторова група P6/mmm, a=0,5503(2), c=0,9171(4) нм)

Tuning a sign of magnetoelectric coupling in paramagnetic NH2(CH3)2Al1-xCrx(SO4)*6H2O crystals by metal ion substitution

Hybrid organometallic systems offer a wide range of functionalities, including magnetoelectric interactions. However, the ability to design on-demand ME coupling remains challenging despite a variety of host-guest configurations and ME phases coexistence possibilities. Here, we report the effect of metal-ion substitution on the magnetic and electric properties in the paramagnetic ferroelectric DMAAS crystals. Doing so we are able to induce and even tune a sign of the ME interactions in the paramagnetic ferroelectric state. Both studied samples with 6.5% and 20% of Cr become paramagnetic, contrary to the initial diamagnetic compound. Due to the isomorphous substitution with Cr the ferroelectric phase transition temperature increases nonlinearly, with the shift being larger for the sample with Cr content of 6.5%. A magnetic field applied along the polar c axis increases ferroelectricity for this sample and shifts Tc to higher values, while inverse effects are observed for sample containing 20% of Cr. The ME coupling coefficient of 1.7ns/m found for a crystal with 20% of Cr is among the highest reported up to now. The observed sign change of ME coupling coefficient with a small change in Cr content paves the way for ME coupling engineering.Comment: 7 pages, 6 figures. New Organometallic Magnetoelectric and Ferroelectric compoun