Environmental assessment of greenhouse gases emission from sheep breeding in Vojvodina region of Serbia

The aim of this work is to show a calculation procedure for obtaining estimations for the carbon footprint of 1 kg of live weight of ewe, ram and lamb at the farm gate, taking into account regional typological features of agricultural production in agroecosystems. The methodology of carbon footprint (CF) calculation is based on the life cycle assessment (LCA) methodology developed for agricultural products. Results revealed that in modern technology of sheep breeding, 21.41 kg CO2 e was emitted on average per kg of body weight of ewe, 19.13 kg CO2 e was emitted on average per kg of body weight of ram, 3.2 kg CO2 e was emitted on average per kg of body weight of lamb. The main distinction of Vojvodina province is the low efficiency of fertiliser application on crop fields and manure management, storage and utilisation, which has as a result high emissions of nitrous oxide. This is the field where the implementation of intensive technologies of precise farming, manure handling, utilisation and management will significantly decrease GHG emission, with preserving yield of crops and quantity and quality of sheep of all categories

CO2 Emission Factors for Coals

Za izračunavanje emisije ugljikova dioksida zbog izgaranja ugljena, emisijski faktor CO2 važan je ulazni parametar. Referentni emisijski faktori prema Uputama Međuvladinog tijela za klimatske promjene iz 2006. godine (engl. Intergovernmental Panel on Climate Change, IPCC) specificirani su prema stupnju pougljenja (coal rank), ali se pri izradi nacionalnog izvješća o stakleničkim plinovima preporučuje primjena nacionalnih emisijskih faktora. Sadržaj ugljika najvažnije je svojstvo ugljena i pokazatelj je stupnja pougljenja (karbonizacije). Međutim mnoga svojstva ugljena vrlo su specifična (npr. sadržaj sumpora, pepela, vlage i macerala) te emisijski faktori CO2 ugljena ne ovise samo o stupnju pougljenja već i o njegovu geografskom porijeklu. U preliminarnom istraživanju, temeljem podataka dobivenih analizom goriva, izračunati su emisijski faktori CO2 za ugljene i treset s područja Livna, BiH: 147,9 t TJ−1 za treset, 109,5 t TJ−1 za lignit i 98,7 t TJ−1 za smeđi ugljen, što odgovara sljedećim donjim ogrjevnim vrijednostima (Hd): 3,6 MJ kg−1, 11,5MJ kg−1 i 20,6 MJ kg−1. Razlika u ogrjevnoj vrijednosti može se djelomično objasniti različitim udjelom ukupne vlage u ispitivanim uzorcima. Usporedba izračunatih emisijskih faktora s referentnim vrijednostima, pokazala je najveća odstupanja kod treseta (39,5 %), potom kod lignita (8,2 %) i smeđeg ugljena (4,3 %).Emission factors are used in greenhouse gas inventories to estimate emissions from coal combustion. In the absence of direct measures, emissions factors are frequently used as a quick, low cost way to estimate emissions values. Coal combustion has been a major contributor to the CO2 flux into the atmosphere. Nearly all of the fuel carbon (99 %) in coal is converted to CO2 during the combustion process. The carbon content is the most important coal parameter which is the measure of the degree of coalification (coal rank). Coalification is the alteration of vegetation to form peat, succeeded by the transformation of peat through lignite, sub-bituminous, bituminous to anthracite coal. During the geochemical or metamorphic stage, the progressive changes that occur within the coal are an increase in the carbon content and a decrease in the hydrogen and oxygen content resulting in a loss of volatiles. Heterogeneous composition of coal causes variation in CO2 emission from different coals. The IPCC (Intergovernmental Panel on Climate Change) has produced guidelines on how to produce emission inventories which includes emission factors. Although 2006 IPCC Guidelines provided the default values specified according to the rank of the coal, the application of country-specific emission factors was recommended when estimating the national greenhouse gas emissions. This paper discusses the differences between country-specific emission factors and default IPCC CO2 emission factors, EF(CO2), for coals. Also, this study estimated EF(CO2) for two different types of coals and peat from B&H, on the basis fuel analyses. Carbon emission factors for coal mainly depend on the carbon content of the fuel and vary with both rank and geographic origin, which supports the idea of provincial variation of carbon emission factors. Also, various other factors, such as content of sulphur, minerals and macerals play an important role and influence EF(CO2) from coal. Carbonate minerals (calcite and siderite) directly contribute CO2 when they decompose during coal combustion. Variations in the maceral content can also influence CO2 emissions; high inertinite contents increase CO2 emissions. Sulphur in coal reduces EF(CO2). Fuel analysis is very important when estimating greenhouse gas emissions and emission factors. In this preliminary study, based on the results of the fuel analysis, CO2 emission factors for coals and peat from Livno, B&H have been calculated. EF(CO2) is defined as the amount of carbon dioxide emission per unit net calorific values of the fuel. Net calorific value (the lower heating value) corresponds to the heat produced by combustion where total water in the combustion products exists as water vapour. The EF(CO2) obtained for sub-bituminous coal, lignite and peat were: 98.7, 109.5, and 147.9 t TJ−1, respectively, which correspond to the following net calorific values: 20.6, 11.5 and 3.6 MJ kg−1. The heating value is generally known to increase with the increase in carbon content (this parameter is connected with the degree of coalification, coal age). The other indispensable parameters are hydrogen, which has a positive effect on the net calorific value, and oxygen and water which impact the net calorific value negatively. The differences in net calorific values can be explained in part by the difference of total moisture content among the different fuel types. The CO2 emission factors calculated in this study were compared with those of IPCC. A significant difference was observed for peat (39.5 %), followed by lignite (8.2 %) and sub-bituminous coal (4.3 %)

Nonleptonic Ω−\Omega^{-} decays and the Skyrme model

Nonleptonic $\Omega^{-}$ decay branching ratios are estimated by means of the QCD enhanced effective weak Hamiltonian supplemented by the SU(3) Skyrme model used to estimate the nonperturbative matrix elements. The model has only one free parameter, namely the Skyrme charge $e$, which is fixed through the experimental values of the octet-decuplet mass splitting $\Delta$ and the axial coupling constant $g_{A}$. The whole scheme is equivalent to that which works well for the nonleptonic hyperon decays. The ratios of calculated amplitudes are in agreement with experiment. However, the absolute values are about twice too large if short-distance corrections and only ground intermediate states are included.Comment: 4 pages, 1 figure, 1 table, version to appear in Phys.Rev.

Assessment of computed tomography simulators used in radiotherapy treatment planning in Serbia, Croatia, and Bosnia and Herzegovina

The purpose of this work was to evaluate computed tomography simulators used in radio-therapy treatment planning in Serbia, Croatia, and Bosnia and Herzegovina. A survey of quality assurance programmes of 24 computed tomography simulators in 16 facilities was conducted. A dedicated CT-to-ED phantom was scanned at 120 kV and 140 kV, to obtain CT-to-ED conversion curves as well as CTDIvol. Thoracal phantoms were scanned in the standard and extended field of view to evaluate the dosimetric effect on treatment planning and delivery. The mean age of the measured scanners was 5.5 years. The mean water HU value was –6.5 (all scanners, all voltages) and air HU value was –997. Extended field of view computed tomography data differ from the standard field of view and differences between conversion curves have significant dosimetric impact. The CTDI data showed a large range of values between centers. Better quality assurance of computed tomography simulators in all countries is recommended. The CT-to-ED curve could be used as default at one voltage and per manufacturer. Extended field of view imaging can be used, but treatment planning should be avoided in the regions out of the standard field of view

Utjecaj hijaluronske kiseline, kalcijeva hidroksida i dentinskih adheziva na odontoblaste i fibroblaste štakora

The aim of this study was to investigate the effects and efficiency of pulp capping preparations based on hyaluronic acid, calcium hydroxide, and dentin adhesive on the pulp tissue of Sprague-Dawley rats. The rats were killed and extracted teeth sectioned transversely through the pulp. The slices were placed in a RPMI 1640 cell culture medium supplemented with 10 % foetal calf serum. During 14 days of cultivation cultures were treated with preparations that contained hyaluronic acid (Gengigel Prof®), and calcium hydroxide (ApexCal®), or with dentin adhesive (Excite®). Cellularity and viability of fibroblasts and odontoblasts was analysed using a haemocytometer. Hyaluronic acid proved most efficient and the least toxic for direct pulp capping. Even though calcium hydroxide and dentin adhesive demonstrated a higher degree of cytotoxicity, their effects were still acceptable in terms of biocompatibility.Cilj ovog rada bio je istražiti djelovanje preparata na bazi hijaluronske kiseline i kalcijeva hidroksida te dentinskog adheziva na pulpno tkivo Sprague-Dawley štakora u svrhu procjene učinkovitosti navedenih materijala kod direktnog prekrivanja pulpe. Izvađeni zubi transverzalno su podijeljeni kroz pulpu. Naresci su uzgajani u RPMI 1640 staničnom mediju obogaćenom s 10 % fetalnoga telećeg seruma u plastičnim bočicama za staničnu kulturu. Kulture su tijekom 14 dana tretirane preparatima s hijaluronskom kiselinom (Gengigel Prof®), kalcijevim hidroksidom (ApexCal®) i dentinskim adhezivom (Excite®). Nakon 14 dana pristupilo se analizi staničnosti i vijabilnosti s pomoću hemocitometra. Iako su preparati na bazi kalcijeva hidroksida i dentinski adheziv pokazali nešto viši stupanj citotoksičnosti, dobiveni su rezultati u granicama biokompatibilnosti. Primjena preparata na bazi hijaluronske kiseline postigla je najbolje rezultate te se ovaj materijal pokazao najboljim za direktno prekrivanje pulpe između tri ispitivana preparata

a multi-ethnic study sample

info:eu-repo/semantics/publishedVersio