A multivariate method for transesterification of soybean oil to produce biodiesel was performed using calcined Mg–Al layered double hydroxide as catalyst. The conversion reached 95.4 % using the ...optimal conditions. The performance of the catalyst for acid oil and high water content was evaluated. The catalysts were characterized and evaluated for their stability.
Graphical Abstract
Sow Prolificacy Depending on Milking Duration Cornelia Petroman; Ioan Petroman; Diana Marin ...
Lucrări științifice zootehnie şi biotehnologii,
09/2023, Letnik:
47, Številka:
2
Journal Article
Odprti dostop
The moment heat appears after farrowing depending on milking duration also depends on farrowing parity: the longer the milking duration, the shorter the anoestrus is. In females with oestrum during ...lactation, we could see that, in primiparous females heat appeared 14.8±1.2 days post partum; the shortest interval between farrowing and heat appearance in milking females was 8.5±0.2 days in primiparous females, while the longest interval was 26.5±1.7 days in pluriparous females. No matter the age category, the highest prolificacy was in females weaned after 28 days of milking, i.e. a mean value of 11.10±2.11 piglets/farrowing.
Due to the multiculturalism of this region, the rural tourism products most demanded by the tourists are natural and cultural resources, and the traditions and customs of the Banat’s village. The ...history of the people living here and the crafts such as pottery or traditional agricultural produce processing constitute but part the tourism offer of the Banat’s village for those in search of authenticity. Introducing these tourism products among other tourism products can help promoting both tourism products and routes because the interest in the tourism destinations is already known.
Ecotourism Management in Banat’s Protected Areas Ionuţ Mircea Petroman; Ioan Csosz; Cornelia Petroman ...
Lucrări științifice zootehnie şi biotehnologii,
09/2023, Letnik:
47, Številka:
2
Journal Article
Odprti dostop
The strategies developed in the field of ecotourism contribute to the creation of a favourable environment in this sector of activity and to the meeting of tourists’ demands without endangering the ...natural resources in the Banat’s protected areas. Management should take into account the main requirements regarding the ecological exploitation of the areas, the judicious exploitation of the tourist flows and the establishment of support thresholds as well as the implementation of material recycling measures in the area. Cooperation between rural and ecological tourism produces benefits such as diversification of economic activities, development of infrastructure and increase of demand for rural goods and services – all this contributing to the long-term economic stability in areas with such natural resources.
Professor Oldřich Kowalski passed away Abbassi, M. T.K.; Mikeš, J.; Vanžurová, A. ...
Differencialʹnaja geometrija mnogoobrazij figur,
2021
52
Journal Article
Recenzirano
This paper is dedicated to the memory of Professor Kowalski who was one of the leading researchers in the field of differential geometry and especially Riemannian and affine geometry. He ...significantly contributed to raising the level of teaching differential geometry by careful and systematic preparation of lectures for students. Prof. Kowalski is the author or co-author of more than 170 professional articles in internationally recognized journals, two monographs, text books for students. Prof. Kowalski collaborated with many mathematicians from other countries, particularly from Belgium, Italy, Japan, Romania, Russia, Morocco, Spain and others. With the death of Professor Oldřich Kowalský mathematical community are losing a significant personality and an exceptional colleague, a kind and dedicated teacher, a man of high moral qualities.
The synthesis, characterization and spectroscopic properties of lipophilic Eu(III) complexes of 3-aminopicolinic acid derivatives are reported. The stable complexes of Eu(III) with the ligands ...3-dodecanoylaminopicolinic acid (3-NHCORpic) and 3-dodecanoylaminopicolinic acid N-oxide (3-NHCORpicNO) exhibit a remarkably high solubility in most common solvents and have enhanced luminescence and spectroscopic properties when compared with their parent 3-amino complexes. A strong absorption in the UV range, intense emission in the visible range, reasonable quantum yield and a long luminescence lifetime are observed. The results obtained show that these complexes can be used as light-conversion molecular devices either in solid state or in solution.
We study the problem of allocating a bundle of perfectly divisible private goods from an axiomatic point of view, in situations where compensations can be made through monetary transfers. The key ...property we impose on the allocation rule requires that no agent should be able to gain by decomposing the problem into sequences of subproblems. Combined with additional standard properties, it leads to a characterization of the rule that shares the total surplus equally. Hence a traditional welfarist rule emerges as the unique consequence of our axioms phrased in a natural economic environment.
Theoretical studies involving minimization of model 3-propanoylaminopicolinic acids (10d- trans , 10d- cis ), methyl ester (10a), and corresponding -N-oxide derivatives (10b, 10c- trans , 10c- cis ) ...using AM1 gave conformations contrary to both sound chemical intuition and experimental data. RHF ab initio calculations using the 6-31G and 6-31G** basis sets on the other hand corroborated spectroscopic data. 3-Amidopicolinic acid derivatives (7a−9a, 7b−9b, 7c−9c, 9d) were prepared and studied by NMR and IR spectroscopy. The results show that a strong intramolecular hydrogen bond between amide-H and the 2-carboxyl substituent results in a planar molecular conformation. This is particularly profound in the 3-acylaminopicolinic acid N-oxides (c-series). When the 2-substituent is a methyl ester on the other hand, repulsion between N-oxide and ester functions induces twisting of the carbomethoxy group out of the plane of the aromatic ring. The type of method used in molecular modeling can have profound impact on the final theoretical result in the case of the above-mentioned class of compounds. Our results indicate, that it is advisable to employ ab initio methods for modeling these types of compounds, and further, that the choice of basis set used for such calculations should depend on the type of information required. Thus, for most purposes pertaining to molecular conformation the 6-31G basis set provides sufficiently sound data in relatively short CPU time. For data related to electronic properties such as involvement of the N-oxide function or spectroscopic information such as IR frequencies or 1H or 15N NMR chemical shifts, the use of polarization functions as contained in the 6-31G** basis set seems to be a must.
A new class of semi-Riemannian and lightlike manifolds (including globally null) is
constructed by using a hypersurface of an orientable Riemannian manifold, endowed
with the second fundamental form ...instead of a metric induced from the ambient
space. We show the existence (or non-existence) of harmonic tensor fields and
harmonic maps and extend to the semi-Riemannian and lightlike case a result of
Chen-Nagano 4. Then we deal with general lightlike submanifolds immersed in a
semi-Riemannian manifold and propose a definition of minimal lightlike
submanifolds, which generalize the one given in 7 in the Minkowski space
{\bf R}^4_1 . Several examples are given throughout.
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