The photoperiodic control of growth and development of Chenopodium Rubrum L. plants in vitro

Influence of the photoperiod on growth, flowering, and seed development in vitro of Chenopodium rubrum L., a short day annual, was examined. Chenopodium rubrum plants modify their growth and reproductive development in accordance with the photoperiod. With an increase of day length, growth was stimulated, flowering was delayed, seed development occurred earlier, and the plants produced more seeds. By altering photoperiods during induction and evocation of flowering, it is shown that the photoperiod experienced by seedlings during early reproductive development determines the pattern of plant growth to the end of ontogenesis, the time to flowering, and the course of seed development. It is therefore concluded that growth and reproductive development of C. rubrum are photoperiod-sensitive to during a precise short part of its life cycle

Anisotropy in the magnetic and electrical transport properties of Fe1-xCrxSb2

We have investigated anisotropy in magnetic and electrical transport properties of Fe1-xCrxSb2 (0<= x <=1) single crystals. The magnetic ground state of the system evolves from paramagnetic to antiferromagnetic with gradual substitution of Fe with Cr. Anisotropy in electrical transport diminishes with increased Cr substitution and fades away by x=0.5. We find that the variable range hopping (VRH) conduction mechanism dominates at low temperatures for 0.4<= x <=0.75.Comment: 5 pages, 6 figure

Anisotropy in magnetic and transport properties of Fe1-xCoxSb2

Anisotropic magnetic and electronic transport measurements were carried out on large single crystals of Fe1-xCoxSb2 (0<= x <=1). The semiconducting state of FeSb2 evolves into metallic and weakly ferromagnetic by substitution of Fe with Co for x<0.5. Further doping induces structural transformation from orthorhombic Pnnm structure of FeSb2 to monoclinic P21/c structure of CoSb2 where semiconducting and diamagnetic ground state is restored again. Large magnetoresistance and anisotropy in electronic transport were observed.Comment: 7 pages, 6 figure

Metod konfigurisanјa upravljačkog sistema otvorene arhitekture rekonfigurabilnog robota za obradu

U radu je prikazan jedan metod konfigurisanja/rekonfigurisanja upravlјačkog sistema otvorene arhitekture rekonfigurabilnih robota za obradu. Na primeru EMC2 upravlјačkog softvera otvorene arhitekture su posredstvom dijagrama za modelovanje dinamičkih procesa definisane aktivnosti sistemintegratora/korisnika u procesu konfigurisanja/rekonfigurisanja upravlјačkog sistema, i uspostavlјene su relacije između softverskih i hardverskih komponenata upravlјanja

REMARKS ON BEST APPROXIMATIONS IN GENERALIZED CONVEX SPACES

Abstract. In this paper, we prove a best approximation theorem in generalized convex spaces. As an application, we derive a result on the existence of a maximal element and a coincidence point theorem in generalized convex spaces. The results of this paper generalize some known results in the literature

Radionuclides and heavy metals in soil, vegetables, and medicinal plants in suburban areas of the cities of Belgrade and Pancevo, Serbia

The content of radionuclides (K-40 , U-238 , Ra-226 , Th-232, and Cs-137) and heavy metals (As, Cd, Cu, and Pb) was determined in samples of soil, vegetables and medicinal plants collected in the period 2007-2017, from two suburban areas of Belgrade - the municipalities of Palilula and Surcin, and Pancevo - the Dr Josif Pancic Institute for the Study of Medicinal Herbs. During the research period, activity concentration of Cs-137 in soil decreased from 16 Bqkg(-1) to 3.9 Bqkg(-1) (Palilula, Belgrade) and from 18 Bqkg(-1) to 12 Bqkg(-1) (Surcin, Belgrade). Mean activity concentrations of natural radionuclides in the soil were higher than the global average. lkend for heavy metal levels, according to the average concentrations found in the soil, were as follows: Cu >Pb >As >Cd for Palilula, Pb >Cu >As >Cd for Surcin and Dr Josif Pancic Institute, Pancevo. The obtained results indicate that the industrial pollution has no impact on food production in the study area and that the main anthropogenic source of radionuclides and heavy metals in soil are mineral phosphorous fertilizers, often used in agricultural fields

An open architecture control system for multi‐axis wood CNC machining center

Abstract: This paper presents an open architecture control system for multi‐axis wood computer numerical control (CNC) milling machining centre, based on LinuxCNC. The wood CNC machining system is supported by an equivalent virtual machine in a CAD/CAM environment, as well as in the control system. Simulation within virtual environment is essential for multi‐axis machining, and the developed virtual machines are used for program verification and monitoring of the machining process. The virtual machine in the programming system allows the verification of the program before it’s sent to the actual machine, while the virtual machine in the control system represents the final verification of the program, as well as the process monitoring system. Configuration of the control system and implementation of virtual machines will be shown, along with the conducted machining experiments that ensued after the successful simulation on developed virtual machines

Bloggers Behavior and Emergent Communities in Blog Space

Interactions between users in cyberspace may lead to phenomena different from those observed in common social networks. Here we analyse large data sets about users and Blogs which they write and comment, mapped onto a bipartite graph. In such enlarged Blog space we trace user activity over time, which results in robust temporal patterns of user--Blog behavior and the emergence of communities. With the spectral methods applied to the projection on weighted user network we detect clusters of users related to their common interests and habits. Our results suggest that different mechanisms may play the role in the case of very popular Blogs. Our analysis makes a suitable basis for theoretical modeling of the evolution of cyber communities and for practical study of the data, in particular for an efficient search of interesting Blog clusters and further retrieval of their contents by text analysis

On the Particles Size Distributions of Diatomaceous Earth and Perlite Granulations

When filtering products with a high level of non-soluble solids and containing filtration-inhibiting substances, a variety of different filter aids can be used. Among others, kieselguhr and perlite are possible materials for this purpose. The selection of the granulation that should be applied depends on the filtered liquid medium and the desired retention level. While perlite is most commonly used for rough filtration, kieselguhr is also suitable for more subtile filtration. In the paper, particle size distributions of three kieselguhr granulations and a perlite granulation are analysed. Particle sizes are measured by the morphometric method commonly used in the microbiology. Basic statistic parameters are calculated for all considered samples and compared. The applicability of hyperbolic and log-hyperbolic functions, in describing the particles size distributions of these granulations is verified. Depending on the imposed filtration requirements, this approach enables simple modelling and composition of a wide variety of different granulations characterised by appropriate particle size distributions from a few available granulations