Polymorphic systems with arrays : decidability and undecidability

Polymorphic systems with arrays (PSAs) is a general class of nondeterministic reactive systems. A PSA is polymorphic in the sense that it depends on a signature, which consists of a number of type variables, and a number of symbols whose types can be built from the type variables. Some of the state variables of a PSA can be arrays, which are functions from one type to another. We present several new decidability and undecidability results for parameterised control-state reachability problems on subclasses of PSAs

Investigation of activated Al-pillared clay efficiency in vegetable oil purification

This paper represents a contribution to the applicability of natural clays and their derivates as adsorbents in the process of purification of vegetable oil. Investigation of textural properties of raw and purified clay samples reveals that during acid activation and Al-pillaring, BET and micropore surface area increases significantly. However, bleaching capacity of clay and its derivates is not determined by using sample surface area, but rather sample total pore volume. Surface area, especially micropore surface area contributes to removal of smaller molecules. This was confirmed by successful elimination of moisture and volatile materials by samples with an appropriate micropore structure. Used samples of clay and its derivates do not significantly influence acid and peroxide values of raw sunflower oil during its treatment

Approximate square-root-time relaxation in glass-forming liquids

We present data for the dielectric relaxation of 43 glass-forming organic liquids, showing that the primary (alpha) relaxation is often close to square-root-time relaxation. The better an inverse power-law description of the high-frequency loss applies, the more accurately is square-root-time relaxation obeyed. These findings suggest that square-root-time relaxation is generic to the alpha process, once a common view, but since long believed to be incorrect. Only liquids with very large dielectric losses deviate from this picture by having consistently narrower loss peaks. As a further challenge to the prevailing opinion, we find that liquids with accurate square-root-time relaxation cover a wide range of fragilities

Solid-Phase Synthesis and In-Silico Analysis of Iron-Binding Catecholato Chelators

Siderophores are iron-complexing compounds synthesized by bacteria and fungi. They are low molecular weight compounds (500-1500 Daltons) possessing high affinity for iron(III). Since 1970 a large number of siderophores have been characterized, the majority using hydroxamate or catecholate as functional groups. The biosynthesis of siderophores is typically regulated by the iron levels of the environment where the organism is located. Because of their exclusive affinity and specificity for iron(III), natural siderophores and their synthetic derivatives have been exploited in the treatment of human iron-overload diseases, as both diagnostic and therapeutic agents. Here, solid-phase approach for the preparation of hexadentate, peptide-based tricatecholato containing peptides is described. The versatility of the synthetic method allows for the design of a common scaffolding structure whereby diverse ligands can be conjugated. With so many possibilities, a computational approach has been developed which will facilitate the identification of those peptides which are capable of providing a high affinity iron(III) binding site. This study reports an integrated computational/synthetic approach towards a rational development of peptide-based siderophores

Switching Distributions for Perpendicular Spin-Torque Devices within the Macrospin Approximation

We model "soft" error rates for writing (WSER) and for reading (RSER) for perpendicular spin-torque memory devices by solving the Fokker-Planck equation for the probability distribution of the angle that the free layer magnetization makes with the normal to the plane of the film. We obtain: (1) an exact, closed form, analytical expression for the zero-temperature switching time as a function of initial angle; (2) an approximate analytical expression for the exponential decay of the WSER as a function of the time the current is applied; (3) comparison of the approximate analytical expression for the WSER to numerical solutions of the Fokker-Planck equation; (4) an approximate analytical expression for the linear increase in RSER with current applied for reading; (5) comparison of the approximate analytical formula for the RSER to the numerical solution of the Fokker-Planck equation; and (6) confirmation of the accuracy of the Fokker-Planck solutions by comparison with results of direct simulation using the single-macrospin Landau-Lifshitz-Gilbert (LLG) equations with a random fluctuating field in the short-time regime for which the latter is practical

Rezultati ispitivanja mašina za obradu zemljišta i setvu heljde i raži

The paper presents an analysis and comparison of the results of exploitation testing the different machines for soil tillage under conventional and reduced tillage, as well as evaluating the quality of the two types of sowing in the production of buckwheat and winter rye, in the conditions of northern Kosovo and Metohia. The previous crop was mercantile maize. The aim of this study was to determine the effects of the aggregate labor indicators for tillage and seeding, in the production of winter rye and buckwheat, and the results will enable proper selection of appropriate technological and technical systems and pointing out the advantages and disadvantages of the applied systems for tillage and seeding. In a variant of conventional tillage in relation to reduced tillage fuel consumption was higher by 27.41 up to 27.73%, while the yields of buckwheat was lower by 22.02%, and winter rye up to 20.18%. Measured values of longitudinal and lateral distances, and depths of buckwheat and rye seeds, are numerically processed using inverse distance interpolation method. Consequently, an appropriate contour maps that present distributions of relative frequencies with respect to longitudinal and lateral seeding distances, as well as seeding depths, are drawn. These maps clearly illustrate accuracy quality of work and operational stability of two analyzed seeding machines having quire different designs of seeding apparatus, in the working conditions of buckwheat and rye seeding.Rad predstavlja analizu i upoređenje rezultata eksploatacionih ispitivanja različitih mašina za obradu zemljišta u okviru konvencionale i redukovane obrade, kao i ocenu kvaliteta rada dva tipa sejalica u proizvodnji heljde i ozime raži u uslovima severnog Kosova i Metohije. Predkultura je bila merkantilni kukuruz. Cilj istraživanja je bio da se utvrde pokazatelji efekata rada agregata za obradu zemljišta i setvu u proizvodnji heljde i ozime raži, a dobijeni rezultati omogućiće pravilan izbor odgovarajućeg tehnološko-tehničkog sistema i ukazati na prednosti i nedostatke primenjenih sistema za obradu zemljišta i setvu. U varijanti konvencionalne obrade u odnosu na redukovanu obradu potrošnja goriva je bila veća za 27,41-27,73%, pri čemu su ostvareni prinosi heljde bili manji za 22,02%, a ozime raži za 20,18%. Kvalitet rada sejalica obuhvatio je određivanje uzdužnog, poprečnog i rasporeda zrna po dubini setvenog sloja. Izmerene vrednosti uzdužnih i poprečnih rastojanja kao i dubine setve heljde i raži, su numerički obrađene metodom interpolacije inverzne udaljenosti. Na osnovu toga, urađene su odgovarajuće konturne mape koje predstavljaju distribucije relativne učestalosti u odnosu na uzdužna i bočna rastojanja semena pri setvi, kao i dubinu setve. Ove mape jasno pokazuju kvalitet rada i radnu stabilnost dveju analiziranih sejalica sa različitom konstrukcijom setvenog aparata, u uslovima rada pri setvi heljde i raži

Assessment of soil erosion rates in Southeastern Serbia using nuclear techniques

Erozija zemljišta vodom predstavlja vaţan problem zaštite ţivotne sredine u Srbiji. Posledica erozije je degradacija zemljišnih resursa, smanjenje plodnosti zemljišta i redukcija poljoprivredne proizvodnje. Najveši intenzitet erozije uoţen je na obradivom zemljištu na strmim padinama. Pretvaranje pašnjaka u obradivo zemljište uticalo je na povešanje prostora zahvašenih procesom erozije. U ovom radu prikazani su preli-minarni rezultati projekta tehniţke saradnje sa MeŤunarodnom agencijom za atomsku energiju ̳Jaţanje kapaciteta za procenu intenziteta erozije zemljišta koriššenjem nuklearnih tehnika u cilju podrške odrţivom upravljanju zemljištem‘ (SRB5003) ţiji je cilj procena intenziteta erozije zemljišta 137Cs-metodom. Istraţivanja sprovedena u basenima Pţinje i Juţne Morave ukazala su na intenzivnu eroziju na ovom prostoru. Istraţivanja še biti nastavljena na nekoliko drugih lokacija, a rezultati še biti upotrebljeni za podršku nacionalnim programima konzervacije zemljišta.Soil erosion by water presents an important environmental problem in Serbia resulting in degradation of the soil resources, reducing soil fertility and agricultural production. The highest intensity of erosion was observed at cultivated land occupying steep slopes. The conversion of pastures to arable land enhances this problem. This study presents the preliminary results of Technical Cooperation Project of International Atomic Energy Agency ̳Strengthening the Capacities for Soil Erosion Assessment Using Nuclear Techniques to Support Implementation of Sustainable Land Management Practices‘(SRB5003) aimed at estimation of soil erosion rates using the 137Cs-method. The investigation of Pčinja and South Morava River Basins in southeastern Serbia revealed intensive erosion in the area. The investigation will continue at several other sites and the results will be used to support national soil conservation policy.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј