249 research outputs found

    Genetic Variability in Different Lucerne (\u3cem\u3eMedicago Sativa\u3c/em\u3e) Genotypes

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    One of the basic goals of modern lucerne breeding programmes is creation of new cultivars with a great potential for high quality and stable yields of both forage and hay (Riday & Brummer, 2002). Such cultivars meet increased needs of animal husbandry and must contribute to diverse farming systems (Luki , 2000). Our trial was aimed at determining genetic variability of yield components in 7 lucerne genotypes, as well as at evaluation of their breeding potential as gene donors to new lucerne cultivar

    Single spin-polarised Fermi surface in SrTiO3_3 thin films

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    The 2D electron gas (2DEG) formed at the surface of SrTiO3_3(001) has attracted great interest because of its fascinating physical properties and potential as a novel electronic platform, but up to now has eluded a comprehensible way to tune its properties. Using angle-resolved photoemission spectroscopy with and without spin detection we here show that the band filling can be controlled by growing thin SrTiO3_3 films on Nb doped SrTiO3_3(001) substrates. This results in a single spin-polarised 2D Fermi surface, which bears potential as platform for Majorana physics. Based on our results it can furthermore be concluded that the 2DEG does not extend more than 2 unit cells into the film and that its properties depend on the amount of SrOx_x at the surface and possibly the dielectric response of the system

    Legislative framework of nuclear security in the Republic of Serbia

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    The paper presents the concept and characteristics of nuclear security, the elements of the nu- clear safety strategy, the legislative framework and the most important solutions from the Law on Radiation and Nuclear Safety and Security. At the international level, the most important entity in this field is the International Atomic Energy Agency, while at the national level, most important is the Directorate for Radiation and Nuclear Safety and Security of Serbia. An important role is played by the Vinča Institute of Nuclear Sciences as the most referential scientific institution in this field, as well as the operational bodies - Nuclear Facilities of Serbia, the Ministry of Internal Affairs, Ministry of Defence, and the Serbian Armed Forces. Engagement of these bodies is carried out in regular peacetime circumstances, emergency situations and wartime. The most important challenges, risks and threats to nuclear security of Serbia were pointed out as well as the need to harmonize norms, procedures and processes in purpose of the strengthening institutional mechanisms in the field of nuclear security

    A novel route for identifying starch diagenetic products in the archaeological record

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    This work introduces a novel analytical chemistry method potentially applicable to the study of archaeological starch residues. The investigation involved the laboratory synthesis of model Maillard reaction mixtures and their analysis through Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS). Thus, starch from sixteen plant species were matured while reacting it with the amino acid glycine. The FTICR-MS analysis revealed > 5,300 molecular compounds, with numerous unique heteroatom rich compound classes, ranging from 20 (Zea mays) to 50 (Sorghum bicolor). These classes were investigated as repositories of chemical structure retaining source and process-specific character, linked back to botanical provenance. We discussed the Maillard reaction products thus generated, a possible pathway for the preservation of degraded starch, while also assessing diagenetic recalcitrance and adsorption potential to mineral surfaces. In some cases, hydrothermal experimentation on starches without glycine reveals that the chemical complexity of the starch itself is sufficient to produce some Maillard reaction products. The article concludes that FTICR-MS offers a new analytical window to characterize starchy residue and its diagenetic products, and is able to recognize taxonomic signals with the potential to persist in fossil contexts.Introduction Materials and methods - Sample preparation and characterization - FTICR-MS analysis Results - Characterization of Maillard reaction products based on atomic ratios (H/C, O/C, N/C, N/O) and compound class distribution - Variations in molecular distribution Discussion - The Maillard reaction products - Preservation pathway - Diagenetic recalcitrance of Maillard reaction products Conclusion

    Momentum-Resolved Electronic Structure of the High-TcT_{c} Superconductor Parent Compound BaBiO3_{3}

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    We investigate the band structure of BaBiO3_{3}, an insulating parent compound of doped high-TcT_{c} superconductors, using \emph{in situ} angle-resolved photoemission spectroscopy on thin films. The data compare favorably overall with density functional theory calculations within the local density approximation, demonstrating that electron correlations are weak. The bands exhibit Brillouin zone folding consistent with known BiO6_{6} breathing distortions. Though the distortions are often thought to coincide with Bi3+^{3+}/Bi5+^{5+} charge ordering, core level spectra show that bismuth is monovalent. We further demonstrate that the bands closest to the Fermi level are primarily oxygen derived, while the bismuth 6s6s states mostly contribute to dispersive bands at deeper binding energy. The results support a model of Bi-O charge transfer in which hole pairs are localized on combinations of the O 2p2p orbitals.Comment: minor changes to text and other figures; includes link to online Supplemental Material; accepted to Phys. Rev. Let

    Trendovi u siliranju leguminoza

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    Modern trends in legumes ensilaging technology are based on the knowledge of biomass from the aspect of suitability for ensilaging, wilting, addition of carbohydrate feed, use of biological additives, etc. Today, the experiments are conducted, worldwide, with inoculates, which, in addition to homofermentative, also contain heterofermentative lactic acid bacteria. Products of such inoculants contribute to the increase of aerobic stability of silages so their implementation is good for all types of silage. In addition to the usage of those additions, modern technology of silage is based on the maximum mechanization of the ensilaging process, as well as preparing the silage in the form of roto-bales and silo tubes (most inexpensive way of conservation) as well as permanent facilities.Savremeni trendovi u tehnologiji siliranja leguminoza zasnivaju se na poznavanju biomasa sa aspekta pogodnosti za siliranje, provenjavanju, dodavanju ugljenohidratnih hraniva, upotrebi bioloÅ”kih dodataka, i dr. Trenutno se u svetu eksperimentiÅ”e sa inokulantima, koji pored homofermentativnih, sadrže i heterofermentativne bakterije mlečne kiseline. Produkti ovakvih inokulanata doprinose povećanju aerobne stabilnosti silaža, pa su navedeni dodaci aktuelni za sve vrste silaža. Osim koriŔćenja navedenih dodataka, savremena tehnologija siliranja se bazira na maksimalnoj mehanizovanosti celokupnog procesa siliranja, kao i pripremanja silaže u formi roto-bala i silokobasica (najeftiniji vid konzervisanja) kao i stalnih objekata

    ViŔegodiŔnje leguminoze i trave - stabilan izvor kvalitetne kabaste stočne hrane

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    Perennial legumes, alfalfa, red clover, bird's foot trefoil, white clover, sainfoin and grasses, cock's foot, meadow fescue, tall fescue, Italian ryegrass, English ryegrass, French ryegrass, red fescue and Timothy grass can be grown successfully in pure crops and in legume-grass mixtures, on different soil types. Their importance in livestock development is based primarily on the great potential for yield of dry matter of over 20 t ha-1 if adequate agro-technical measures have been applied. Also, perennial legumes are characterized with high content of nutritive substances, especially protein and represent the most important protein source in livestock nutrition. Depending on the species and pheno stage of utilization, the content of crude proteins in grasses varies from 100 to 174,6 g kg-1 of DM, and in perennial legumes from 190,0 to 228,8 g kg-1 of DM. Livestock feed obtained from these plant species can be used in several ways, from grazing as most efficient and economical way, to preparation of hay and high quality silages and haylages. Stated forage species are very important in sustainable agriculture and organic production, considering that they carry out the process of biological fixation of nitrogen, but also from the ecological aspect. By using diverse selection/breeding material numerous domestic cultivars of perennial legumes and grasses have been created which are characterized with high potential for main agronomical traits.ViÅ”egodiÅ”nje leguminoze, lucerka, crvena detelina, žuti zvezdan, bela detelina, esparzeta i trave ježevica, livadski vijuk, visoki vijuk, italijanski ljulj, engleski ljulj, francuski ljulj, crveni vijuk i mačiji rep, mogu se uspeÅ”no gajiti u čistom usevu ili u leguminozno-travnim smeÅ”ama, na različitim tipovima zemljiÅ”ta. Njihov značaj u razvoju stočarstva, pre svega, se zasniva na visokom potencijalu za prinos suve materije, koji se uz primenu savremenih agrotehničkih mera kreće i preko 20 t ha-1. Pored toga, viÅ”egodiÅ”nje leguminoze se odlikuju visokim sadržajem hranljivih materija, posebno proteina i predstavljaju najvažniji izvor proteina u ishrani domaćih životinja. U zavisnosti od vrste i fenofaze iskoriŔćavanja sadržaj sirovih proteina kod trava se kreće od 100 do 174,6 g kg-1 SM, a kod viÅ”egodiÅ”njih leguminoza od 190,0 do 228,8 g kg-1 SM. Stočna hrana dobijena od ovih biljnih vrsta može se koristiti na viÅ”e načina, od ispaÅ”e kao najefikasnijeg i najekonomičnijeg načina, preko pripreme sena, do spravljanja kvalitetnih senaža i silaža. Navedene krmne vrste imaju veoma značajno mesto u održivoj poljoprivredi i organskoj proizvodnji, obzirom da obavljaju proces bioloÅ”ke fiksacije azota, veoma su značajne i sa ekoloÅ”kog aspekta. KoriŔćenjem divergentnog selekcionog materijala stvoren je veliki broj domaćih sorti viÅ”egodiÅ”njih leguminoza i trava koje se odlikuju visokim potencijalom za osnovna agronomska svojstva

    ZnTiO3 Ceramic Nanopowder Microstructure Changes During Compaction

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    ZnTiO3 nanopowder as a constitutive component in compact production was primarily characterised. Scanning electron micrographs of as received powder were recorded. Mercury porosimetry and nitrogen adsorption were also performed on loose powder. Particle size distribution in a water powder suspension was determined with a laser particle size analyser. Compaction was performed on different pressures in a range from 100 to 400 MPa using the uniaxial double sided compaction technique without binder and lubricant. Micrographs of compacted specimens were obtained using scanning electron microscopy and atomic force microscopy. Pore size distribution was also determined by mercury porosimetry and nitrogen adsorption. Results revealed that with increasing pressure during compaction interagglomerate pores diminish in size until they reach some critical diameter related to the intra-agglomerate pore size

    Uticaj bakterijskog inokulanta mlečne kiseline sa dodatkom enzima i gnječenog ječma na kemijski sastav i degradaciju proteina u silaži lucerke

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    In the experiment, forage (dry matter 216.3 g.kg-1) from the 1st cut of alfalfa (Medicago, sativa L.) cv, Radius, mown at the early flowering stage, was ensiled. Alfalfa was ensiled without inoculants; with lactic acid bacteria and enzyme inoculants; with rolled barley; or with rolled barley and lactic acid bacteria and enzyme inoculants. Rolled barley was added in amounts of 50,100, 150 and 200 g.kg-1 of alfalfa forage, The bacterial acid enzyme inoculants (Bactozym) contained cultures of Lacto bacillus casein, Enterococcus faecium M74 and Pediococcus sp. (a total of 1 5 x 109 CPU in Ig of friable preparation) in the powdered part and the cellulase-hemicellulase complex (25000 n cat. in 1ml) and glucose-oxidase (4000 n cat. in 1ml) in the liquid part. The inoculants was used in a water solution in the amount of 10mg bacterial component and 0,2 ml enzymatic component / kg-1 alfalfa forage. The supplement of only rolled barley to alfalfa forage was found to have no significant effect on improving the processes of proteolysis and deamination in this type of silages, compared to alfalfa silages made with bacterial and enzyme inoculants. Significantly lower crude protein and WSC losses in the fermentation process, increased intensity of lactic acid fermentation, the lack of propionic and butyric acid fermentation, and significantly reduced processes of protein degradation were found in alfalfa-rolled barley silages made with the addition of lactic acid bacteria and enzyme inoculants.U ovom ogledu, silirana je stočna hrana (suva materija 216.3 g.kg-1) koja potiče od 1. otkosa lucerke (Medicago, sativa L.) cv, Radius, koÅ”ene u ranom stadijumu cvetanja. Lucerka je silirana bez inokulanata; sa bakterijama mlečne kiseline i enzimskim inokulantom; sa gnječenim ječmom; ili sa gnječenim ječmom i bakterijom mlečne kiseline i enzimskim inokulantom. Gnječeni ječam je dodavan u količinama od 50, 100, 150 200 g.kg-1 stočne hrane od lucerke. Bakterijski enzimski inokulant (Bactozym) koji je sadržavao sledeće kulture Lacto bacillus casei ,Enterococcus faecium M74 i Pediococcus sp. ( ukupno 15 x IO9 CFU u Ig preparat koji se lako pretvara u prah) u prahu i kompleks celulaza-hemicelulaza (25000 n cat. u l ml) i glukoza-oksidaza (4000 n cat u Iml) u tečnom delu. Inokulant je koriŔćen u vodenom rastvoru u količini od 10mg bakterijske komponente i 0.2ml enzimske komponente / kg-1 lucerke. Dodavanje samo gnječenog ječma lucerkinom krmivu nije imalo značajnog efekta na poboljÅ”anje procesa proteoloze i deaminacije u ovoj vrsti silaže, u poređenju sa silažama od lucerke koje su pravljene uz pomoć bakterijskih i enzimskih inokulanata. Signifikantno manje sirovog proteina kao i gubici WSC-a u procesu fermentacije, povećan intenzitet fermentacije mlečne kiseline, nedostatak fermentacije propionske i buterne kiseline, i znatno redukovani proces degradacije proteina su pronađeni u silaži od lucerke i gnječenog ječma uz dodatak bakterije mlečne kiseline i enzimskog inokulanta
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