165 research outputs found
NH3 Emissions From Treated Buffalo Manure Application In Mediterranean climate And Comparison To ALFAM Model
Ammonia volatilization is widely recognized as one of the major environmental European problems, due to the increase in livestock farming activities. As a consequence, accurate ammonia assessment is needed in order to control ammonia emissions and to update national emission inventories. Besides some uncertainties still related to the measurement methods, another important issue is the necessity of investigating a different kind of fertilizers. In the last few years, considerable attention has been paid to many manure treatments prior to field application.
This study aims to assess ammonia emissions from the field application of separated buffalo manure digestate in the Mediterranean climate, in order to improve the emission inventory for this animal species, reared mostly in South Italy. Two measuring methods were used: wind tunnel (WT) and Integrated Horizontal flux (IHF). Moreover, ammonia emission measured were compared to those obtained running the statistical regression model ALFAM. This model based on Michaelis-Menten type equation is often used to predict cumulative ammonia loss and since it is based on a significant dataset is useful to discuss the effectiveness of the emission measured. The total ammonia losses measured in 7 days were 26.39 and 49.24 kg N ha-1, for WT and IHF, respectively. Although the predicted total emissions were 40.99 and 36.56 kg N ha-1, for IHF and WT, respectively, it is possible to observe the good accordance of the ALFAM model with the temporal pattern of both methods
Ammonia Emission Assessment After Buffalo Manure And Digestate Application
Quite recently, considerable attention has been paid to the effect of anaerobic digestion on ammonia emissions from digestate spreading in the field, due to the growing interest in NH3 emission monitoring. Unfortunately, there are still some different studies finding about the effect of anaerobic digestion on ammonia emissions. Thus, more research into this topic is still necessary before obtaining a definitive answer to the increment or not in emission. For this purpose, this paper proposes comparison study between ammonia emissions from buffalo raw (Farmyard) manure and digestate on bare soil under Mediterranean climate, using the wind tunnel equipped with acid traps, to assess the ammonia emission fluxes. The sampling campaign, in three replicates, lasted each time, for 6 days to ensure that most of the ammonia has been emitted before the end of each campaign. The results obtained indicate that a diurnal correlation between emission and external temperature occurs, especially during the first days. Specifically for both fertilizers, ammonia volatilization increased with air temperature raising. Overall, the total digestate cumulative NH3 emission is 54% higher than raw manure emission. This is certainly due to the Total NH4+-N rate, which was 55,8kg ha-1 for the raw manure and 107 kg ha-1 for the digestate, around 1,9 times higher for the digestate TAN content. Finding suggests the need for adjusting digestate application rate based on TAN content, in order to reduce the impact on the environment
Predicting land use change on a broad area: Dyna-CLUE model application to the Litorale Domizio-Agro Aversano (Campania, South Italy)
The long-standing awareness of the environmental impact of land-use change (LUC) has led scientific community to develop tools able to predict their amount and to evaluate their effect on environment, with the aim supporting policy makers in their planning activities. This paper proposes an implementation of the Dyna-CLUE (Dynamic Conversion of Land Use and its Effects) model applied to the Litorale Domizio-Agro Aversano, an area of Campania region, which needs interventions for environmental remediation. Future land use changes were simulated in two different scenarios developed under alternative strategies of land management: scenario 1 is a simple projection of the recent LUC trend, while scenario 2 hypothesises the introduction of no-food crops, such as poplar (Populus nigra L.) and giant reed (Arundo donax L.), in addition to a less impactful urban sprawl, which is one of the main issues in the study area. The overall duration of simulations was 13 years, subdivided into yearly time steps. CORINE land cover map of 2006 was used as baseline for land use change detection in the study area. Competition between different land use types is taken into account by setting the conversion elasticity, a parameter ranging from 0 to 1, according to their capital investment level. Location suitability for each land use type is based on logit model. Since no actual land use already exists for the alternative crops investigated in scenario 2, a suitability map realised through a spatial multicriteria decision analysis was used as a proxy for its land use pattern. The comparison of the land use in 2012 and scenario 1, evaluated through the application of Kappa statistics, showed a general tendency to expansion of built-up areas, with an increase of about 2400 ha (1.5% of the total surface), at the expense of agricultural land and those covered by natural vegetation. The comparison of the land use in 2012 and scenario 2 showed a less significant spread of built-up areas, affecting approximately 750 ha (0.5% of the total surface). Moreover, the introduction of alternative crops on about 10,000 ha, that is 6.8% of the total surface, would result in a significant decrease of arable land and a lower decrease of permanent crops, respectively equal to 6800 ha and 2900 ha. This work highlighted the importance and the potential of predicting land-use change models as valid tools supporting decisions, especially in those regions needing interventions aimed to environmental remediation, as in the case study examined in this paper
Comparison of Bioengineered Scaffolds for the Induction of Osteochondrogenic Differentiation of Human Adipose-Derived Stem Cells
osteochondral lesions may be due to trauma or congenital conditions. In both cases, therapy is limited because of the difficulty of tissue repair. tissue engineering is a promising approach that relies on designed scaffolds with variable mechanical attributes to favor cell attachment and differentiation. human adipose-derived stem cells (hASCs) are a very promising cell source in regenerative medicine with osteochondrogenic potential. based on the assumption that stiffness influences cell commitment, we investigated three different scaffolds: a semisynthetic animal-derived GelMA hydrogel, a combined scaffold made of rigid PEGDA coated with a thin GelMA layer and a decellularized plant-based scaffold. we investigated the role of different biomechanical stimulations in the scaffold-induced osteochondral differentiation of hASCs. we demonstrated that all scaffolds support cell viability and spontaneous osteochondral differentiation without any exogenous factors. In particular, we observed mainly osteogenic commitment in higher stiffness microenvironments, as in the plant-based one, whereas in a dense and softer matrix, such as in GelMA hydrogel or GelMA-coated-PEGDA scaffold, chondrogenesis prevailed. we can induce a specific cell commitment by combining hASCs and scaffolds with particular mechanical attributes. however, in vivo studies are needed to fully elucidate the regenerative process and to eventually suggest it as a potential approach for regenerative medicine
Search for Higgs and Z Boson Decays to J/ψγ and Υ(nS)γ with the ATLAS Detector
A search for the decays of the Higgs and Z bosons to J/ψγ and Υ(nS)γ (n=1,2,3 ) is performed with pp collision data samples corresponding to integrated luminosities of up to 20.3fb¯¹ collected at √s =8TeV with the ATLAS detector at the CERN Large Hadron Collider. No significant excess of events is observed above expected backgrounds and 95\% CL upper limits are placed on the branching fractions. In the J/ψγ final state the limits are 1.5×10¯³ and 2.6×10¯⁶ for the Higgs and Z boson decays, respectively, while in the Υ(1S,2S,3S)γ final states the limits are (1.3,1.9,1.3)×10¯³ and (3.4,6.5,5.4)×10¯⁶, respectively
A search for high-mass resonances decaying to τ + τ − in pp collisions at √s =8 TeV with the ATLAS detector
A search for high-mass resonances decaying into τ + τ − final states using proton-proton collisions at s √ =8 TeV produced by the Large Hadron Collider is presented. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 19.5-20.3 fb −1 . No statistically significant excess above the Standard Model expectation is observed; 95% credibility upper limits are set on the cross section times branching fraction of Z ′ resonances decaying into τ + τ − pairs as a function of the resonance mass. As a result, Z ′ bosons of the Sequential Standard Model with masses less than 2.02 TeV are excluded at 95% credibility. The impact of the fermionic couplings on the Z ′ acceptance is investigated and limits are also placed on a Z ′ model that exhibits enhanced couplings to third-generation fermions
Search for anomalous production of prompt same-sign lepton pairs and pair-produced doubly charged Higgs bosons with √s=8 TeV pp collisions using the ATLAS detector
A low-background inclusive search for new physics in events with same-sign dileptons is presented. The search uses proton-proton collisions corresponding to 20.3 fb⁻¹ of integrated luminosity taken in 2012 at a centre-of-mass energy of 8 TeV with the ATLAS detector at the LHC. Pairs of isolated leptons with the same electric charge and large transverse momenta of the type e ± e ± ,e ± μ ± , and μ ± μ ± are selected and their invariant mass distribution is examined. No excess of events above the expected level of Standard Model background is found. The results are used to set upper limits on the cross-sections for processes beyond the Standard Model. Limits are placed as a function of the dilepton invariant mass within a fiducial region corresponding to the signal event selection criteria. Exclusion limits are also derived for a specific model of doubly charged Higgs boson production
Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s=8 TeV with the ATLAS detector
A search for pair production of vector-like quarks, both up-type (T ) and down-type (B ), as well as for four-top-quark production, is presented. The search is based on pp collisions at √s=8 TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 20.3 fb⁻¹. Data are analysed in the lepton-plus-jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets. Dedicated analyses are performed targeting three cases: a T quark with significant branching ratio to a W boson and a b -quark (TT ¯ →Wb +X), and both a T quark and a B quark with significant branching ratio to a Higgs boson and a third-generation quark (TT ¯ →Ht +X and BB ¯ →Hb +X respectively). No significant excess of events above the Standard Model expectation is observed, and 95% CL lower limits are derived on the masses of the vector-like T and B quarks under several branching ratio hypotheses assuming contributions from T→Wb , Zt , Ht and B→Wt , Zb , Hb decays. The 95% CL observed lower limits on the T quark mass range between 715 GeV and 950 GeV for all possible values of the branching ratios into the three decay modes, and are the most stringent constraints to date. Additionally, the most restrictive upper bounds on four-top-quark production are set in a number of new physics scenarios
Search for the Standard Model Higgs boson produced in association with top quarks and decaying into bb ¯ in pp collisions at √s = 8 TeV with the ATLAS detector
A search for the Standard Model Higgs boson produced in association with a pair of top quarks, tt ¯ H , is presented. The analysis uses 20.3 fb¯¹ of pp collision data at √s = 8 TeV, collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H to bb ¯ decay mode and uses events containing one or two electrons or muons. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities. A neural network is used to discriminate between signal and background events, the latter being dominated by tt ¯ +jets production. In the single-lepton channel, variables calculated using a matrix element method are included as inputs to the neural network to improve discrimination of the irreducible tt ¯ +bb ¯ background. No significant excess of events above the background expectation is found and an observed (expected) limit of 3.4 (2.2) times the Standard Model cross section is obtained at 95% confidence level. The ratio of the measured tt ¯ H signal cross section to the Standard Model expectation is found to be μ = 1.5 ± 1.1 assuming a Higgs boson mass of 125 GeV
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