As(V) adsorption using MFe2O4 (M=Cd2+, Ni2+) ferrite nanoparticles

The paper present the possibilities of arsenic removal from aqueous solutions using as adsorbent MFe2O4 (M=Cd2+, Ni2+) ferrite nanoparticles due to the affinity of arsenic towards iron ions. The ferrites were obtained after a heating treatment of the cadmium respectively nickel ferrioxalate coordination compounds, as precursors, at 500oC. From the two studied adsorbent material the nickel ferrite developed a higher maximum adsorption capacity (132 µg As(V)/g of ferrite) than the cadmium ferrite (109 µg As(V)/g of ferrite) in the removal process of As(V) from aqueous solutions. In both cases the equilibrium between the adsorbent and adsorbate was achieved in 60 minutes

Electrical Properties of Epitaxial Ferroelectric Heterostructures

In the context of miniaturization of devices, ferroelectric materials are used as multifunctional materials for their well-known intrinsic properties, especially for the switching of polarization in an applied electric field. The high-quality epitaxial thin film structures are used for the possibility to study different effects as low dimensions, interface, strain and strain gradients on ferroelectric materials and other electric characteristics, also representing a possibility to obtain new phenomena and properties that can be used for development of new devices with different functionalities. This chapter is a summary of the ferroelectric and dielectric behaviour of epitaxial thin films of Pb(Zr,Ti)O3 (PZT) and BaTiO3 (BTO) obtained by pulsed laser deposition and the correlation with structural quality of the layers and with different electrostatic conditions induced either by electrodes or by the different interlayers. For this purpose in the first part, studies regarding the influence of the substrates and of different top electrodes are performed for Pb(Zr,Ti)O3 (PZT) 52/48. In the second part, we focused on artificial multiferroic structures from alternating layers of PZT 20/80 or BaTiO3 (BTO) as ferroelectric phase and CoFe2O4 (CFO) as magnetic material. We found that interface configuration and strain engineering could control ferroelectric hysteresis, the capacitance or the leakage current magnitude

Yield at 75 european soybean varieties from different maturity groups in the climatic conditions of the Transylvanian Plain

Soybean being the most important legume plant for grains, the high protein and oil content determines many uses, which leads to expansion of soybean crop areas. The experiment was conducted at Agricultural Research and Development Station Turda (ARDS Turda) in the climatic conditions of the 2018 and 2019. Biological material included 75 Romanian varieties (12) and foreign genotypes (63), from different maturity groups (000 - II). The rainfall and temperature varied in the two-year study which determined differences on average yield obtained for each maturity group. The highest average yield for the maturity groups 00, 0, I, II was obtained in the climatic conditions of the year 2019, instead the behavior of the very early genotypes (000) was different, the year 2018 being more favorable. The maturity group recommended till now for the Transylvanian Plain was very early (000) and early (00), but from the data presented the highest yields were obtained by the maturity groups 0 (2719 kg/ha), I (2895 kg/ha) and I + II (2732 kg/ha). A continuation of the study is required, to establish the suitable maturity group for the new conditions of Transylvanian Plain

Unveiling the double-well energy landscape in a ferroelectric layer

The properties of ferroelectric materials, which were discovered almost a century ago¹ , have led to a huge range of applications, such as digital information storage² , pyroelectric energy conversion³ and neuromorphic computing⁴⁻⁵ . Recently, it was shown that ferroelectrics can have negative capacitance⁶⁻¹¹, which could improve the energy efficiency of conventional electronics beyond fundamental limits¹²⁻¹⁴. In Landau–Ginzburg–Devonshire theory¹⁵⁻¹⁷, this negative capacitance is directly related to the doublewell shape of the ferroelectric polarization–energy landscape, which was thought for more than 70 years to be inaccessible to experiments¹⁸. Here we report electrical measurements of the intrinsic double-well energy landscape in a thin layer of ferroelectric Hf₀.₅Zr₀.₅O₂. To achieve this, we integrated the ferroelectric into a heterostructure capacitor with a second dielectric layer to prevent immediate screening of polarization charges during switching. These results show that negative capacitance has its origin in the energy barrier in a double-well landscape. Furthermore, we demonstrate that ferroelectric negative capacitance can be fast and hysteresis-free, which is important for prospective applications¹⁹. In addition, the Hf₀.₅Zr₀.₅O₂ used in this work is currently the most industry-relevant ferroelectric material, because both HfO₂ and ZrO₂ thin films are already used in everyday electronics²⁰. This could lead to fast adoption of negative capacitance effects in future products with markedly improved energy efficiency

Effects of complex fertilizer on yield components and yield of some soybean genotypes

Fertilization is one of the main economic and health-promoting factors in crop cultivation. Field trials were carried out in 2019, in the experimental field of Soybean Breeding Laboratory from Agricultural Research and Development Station in Turda (ARDS Turda), based on a subdivided parcel design with two replications, using plots of 5 m2 . The biological material used in this study was created at ARDS Turda, 13 semi-early, early and very early soybean genotypes being evaluated: 7 varieties (Perla, Onix, Felix, Carla, Caro TD, Ada TD, Raluca TD) and 6 perspective lines (T-161, T- 295, T-165, T-6126, T-6117 and T-166). Fertilization was carried out with NPK 16:16:16 complex fertilizer applying the following doses: 150 kg/ha, 200 kg/ha, 250 kg/ha and unfertilized (Control). At the end of the growing season the genotypes were characterized by: plant height (cm), number of pods/plant, number of seeds/plant, seeds weight/plant (g), TKW (g), yield (kg/ha). The reported data is the average of 10 measurements. Statistical calculations were accomplished in Excel 2013 (Microsoft, USA) highlighting differences between studied genotypes and applied doses. The average of the seed/plant had small variations, in this year's conditions; the grain size varied between 122 g and 162 g and the maximum yield was about 3 to/ha at the dose of 200 kg/ha complex fertilizer

Tungsten Nanoparticles Produced by Magnetron Sputtering Gas Aggregation: Process Characterization and Particle Properties

Tungsten and tungsten nanoparticles are involved in a series of processes, in nanotechnology, metallurgy, and fusion technology. Apart from chemical methods, nanoparticle synthesis by plasma offers advantages as good control of size, shape, and surface chemistry. The plasma methods are also environmentally friendly. In this chapter, we present aspects related to the magnetron sputtering gas aggregation (MSGA) process applied to synthesis of tungsten nanoparticles, with size in the range of tens to hundreds of nanometers. We present the MSGA process and its peculiarities in the case of tungsten nanoparticle synthesis. The properties of the obtained particles with a focus on the influence of the process parameters over the particle production rate, their size, morphology, and structure are discussed. To the end, we emphasize the utility of such particles for assessing the environmental and biological impacts in case of using tungsten as wall material in thermonuclear fusion reactors