1,178 research outputs found
Flusso tridimensionale e viscoso nei ventilatori assiali: confronto fra risultati sperimentali e numerici
La conoscenza del flusso tridimensionale a valle della girante dei ventilatori assiali è di
fondamentale importanza per valutare la distribuzione delle perdite fluidodinamiche nella
macchina e per intervenire con proposte di modifiche della conformazione dei condotti palari in
fase di progettazione. Per raggiungere questo obiettivo è particolarmente utile poter affiancare
ai metodi di indagine sperimentale codici di calcolo evoluti ed affidabili.
Per verificare la validità di tale impostazione nel presente lavoro si è effettuato il confronto
fra i risultati dell’indagine sperimentale condotta con sonde ad alta risposta in frequenza e
quelli derivanti dalla simulazione del flusso con un codice di calcolo su un ventilatore assiale di
tipo industriale.The knowledge of detailed 3-D flow field downstream of rotor blade in industrial axial flow fan
is important both to evaluate the aerodynamic losses and to improve the aerodynamic design of
these machines.
To achieve these goals it is very important to use a reliable fluid dynamic computational code.
In this paper a comparison between experimental and numerical results downstream an axial
fan are presented
Simulation of Land Use and Investment Behaviour under Different Policy Scenarios: Results of the extended farm/household model. Factor Markets Working Paper No. 27, July 2012
Factor markets are a central issue in analyses of farm development and of agricultural sector vitality. Among the different production factors, land is one of the most studied. Several studies seek to estimate the effect of government policy payments on land value or land rental prices. The studies mostly agree that government payments and other types of policy support are significant in explaining land prices and account for a large share of them. In October 2011, the European Commission published a new policy proposal for the common agricultural policy (CAP) up to 2020. The proposed regulation includes a shift from historical to regional payments. The objective of this paper is to provide an ex ante analysis of the impact of the new CAP policy instruments on the land market. In particular, the effect of the regionalisation of payments in Italy is examined. The analysis is based on the use of a mathematical programming model to simulate the changes in land demand for a farm in Emilia Romagna. The results highlight the relevance of the new policy mechanism in determining a change in land demand. Yet the effect is highly dependent on initial ownership of entitlements under the historical payment scheme
Simulation of Land Use and Investment Behaviour under Different Policy Scenarios Results of the extended farm/household model
Factor markets are a central issue in analyses of farm development and of agricultural sector
vitality. Among the different production factors, land is one of the most studied. Several studies
seek to estimate the effect of government policy payments on land value or land rental prices. The
studies mostly agree that government payments and other types of policy support are significant
in explaining land prices and account for a large share of them. In October 2011, the European
Commission published a new policy proposal for the common agricultural policy (CAP) up to
2020. The proposed regulation includes a shift from historical to regional payments. The
objective of this paper is to provide an ex ante analysis of the impact of the new CAP policy
instruments on the land market. In particular, the effect of the regionalisation of payments in
Italy is examined. The analysis is based on the use of a mathematical programming model to
simulate the changes in land demand for a farm in Emilia Romagna. The results highlight the
relevance of the new policy mechanism in determining a change in land demand. Yet the effect is
highly dependent on initial ownership of entitlements under the historical payment scheme
Farm/Household-Level Simulation: Results of Testing Policy and Other Scenarios. Factor Markets Working Document No. 54, June 2013
Among the different production factors, land is the one that most often limits farm development and one of the most studied. The connection between policy and other context variables and land markets is at the core of the policy debate, including the present reform of the Common Agricultural Policy. The proposal of the latter has been published in October 2011 and in Italy it will include the switch of the payment regime from an historical to a regional basis. The authors’ objective is to simulate the impact of the proposed policy reform on the land market, particularly on land values and propensity to transaction. They combine insights and data from a farm household investment model revised and extended in order to simulate the demand curve for land in different policy scenarios and a survey of farmers stated intention carried out in the province of Bologna (Italy) in 2012. Based on these results, the authors calibrate a mathematical programming model of land market exchanges for the province of Bologna and use this model form simulation. The results of the model largely corroborate the results from the survey and both hint at a relevant reaction of the land demand and supply to the shift from the historical to the regionalised payments. As effect, the regionalisation would result in increased rental prices and in a tendency to the re-allocation of land
Effects of 2013 Cap reform on land market: regionalized farm payments and changes in farmers’ intended behaviour
The CAP reform process has been a central issue for agricultural economics research in recent years, and is gaining further attention in view of the post-2013 perspectives (Viaggi et al., 2010; Bartolini et al., 2011). Today the CAP is in the middle of a new reform process. Through the debate generated by the official proposals, published in October 2011 (COM(2011)625/3), the European Union (EU) engaged in a revision of the CAP ended on 26 June 2013 when a political agreement has been reached (IP/13/613, MEMO-13-621 and IP/13/864). In particular, in Italy the switch of the payment regime from historical to regional bases will take place. The underlying assumption is that the shift to regionalized payments changes the remuneration of inputs and has an impact on farmers’ allocation of fixed resources. In this context, farmers are expected to adjust their plans to the new policy environment as the regionalization of support is meant to create a change in incentives faced by farmers. The objective of this thesis is to provide an ex-ante analysis of the potential impact of the introduction of regionalized payments, within the post-2013 CAP reform, on the land market. Regionalized payments seem to produce differentiated effects and contribute to a general (slight) increase of land exchanges. The individual reaction to the new payments introduction would be different depending on location and specialization. These effects seem to be also strongly influenced by the difference in historical payments endowment and value, i.e. by the previous historical system of distribution of payments
Farm/Household-Level Simulation Results of Testing Policy and Other Scenarios
Among the different production factors, land is the one that most often limits farm development and one of the most studied. The connection between policy and other context variables and land markets is at the core of the policy debate, including the present reform of the Common Agricultural Policy. The proposal of the latter has been published in October 2011 and in Italy it will include the switch of the payment regime from an historical to a regional basis. The authors’ objective is to simulate the impact of the proposed policy reform on the land market, particularly on land values and propensity to transaction. They combine insights and data from a farm household investment model revised and extended in order to simulate the demand curve for land in different policy scenarios and a survey of
farmers stated intention carried out in the province of Bologna (Italy) in 2012. Based on these results,
the authors calibrate a mathematical programming model of land market exchanges for the province of Bologna and use this model form simulation. The results of the model largely corroborate the results from the survey and both hint at a relevant reaction of the land demand and supply to the shift from the historical to the regionalised payments. As effect, the regionalisation would result in increased rental prices and in a tendency to the re-allocation of land
The Impact of the 2013 CAP Reform on Land Markets in Italy
The connection between policy and other context variables and land markets is at the core of the policy debate, including the present reform of the Common Agricultural Policy (CAP). The current proposals for the post- 2013 CAP will include the switch of the payment regime from an historical to a regional basis. This component, as well as the greening and other ‘microprovisions’ can have an effect on the land markets. The objective of this chapter is to assess the potential impact of the proposed policy reform (in particularconcerning the regionalisation of payments) on the land market. Attention will focus on changes in propensity to rent-in and out and in transactions due to the proposed provisions for the post-2013 CAP. To achieve this goal, the authors jointly use: a) a survey of farmers stated intention, and b) a mathematical programming model simulating the land markets in different policy scenarios. Both are applied to a case study at the scale of the province of Bologna, Italy (NUTS 3).
The results of the model corroborate the results from the survey, though the model is much more reactive to policy changes, while the survey has a larger share of “no changes”. Both hint at a relevant reaction of the land demand and supply to the shift from the historical to the regionalised payments, due to the differentiated and opposite effects that the reform would have on different farm types and sub-regions.
The payment would be more capitalised into the land value, at the margin, as long as it is less constrained by the ownership of entitlements. As an effect, the regionalisation would potentially result in increased rental prices and in a tendency to re-allocate land
The Impact of the SFP System on Italian Farmland Prices and Tenure Contracts. Factor Markets Working Document No. 65, August 2013
EDITED VERSION TO BE PUBLISHED SOON.
The aim of this paper is to contribute to the estimation of the potential effects of the CAP reform on propensity to transaction, particularly comparing the effect of different new instruments/policy settings with the current policy (CAP health check) used as a baseline. The work is focused on three of new policy instruments within the post 2013 CAP reform proposal: regionalization, greening and capping. The first and second are analysed in more detail.
The analysis will be based on a survey of farmers in the Province of Bologna, Emilia Romagna, Italy. The questionnaire focuses on mechanism of access to land and related incentives towards different land use/economic behaviour. The survey includes information about respondent characteristics (farm, farmer, household and payments received) and stated intention about potential changes in land operated under alternative agricultural policy scenarios (particularly the post-2013 reform proposals)
Prognostic significance of diabetes and stress hyperglycemia in acute stroke patients
Background Hyperglycemic non-diabetic stroke patients have a worse prognosis than both normoglycemic and diabetic patients. Aim of this study was to assess whether hyperglycemia is an aggravating factor or just an epiphenomenon of most severe strokes. Methods In this retrospective study, 1219 ischemic or hemorrhagic stroke patients (73.7 +/- 13.1 years) were divided into 4 groups: 0 = non-hyperglycemic non-diabetic, 1 = hyperglycemic non-diabetic, 2 = non-hyperglycemic diabetic and 3 = hyperglycemic diabetic. Hyperglycemia was defined as fasting blood glucose >= 126 mg/dl (>= 7 mmol/l) measured the morning after admission, while the diagnosis of diabetes was based on a history of diabetes mellitus or on a glycated hemoglobin >= 6.5% (>= 48 mmol/mol), independently of blood glucose levels. All diabetic patients, except 3, had Type 2 diabetes. The 4 groups were compared according to clinical history, stroke severity indicators, acute phase markers and main short term stroke outcomes (modified Rankin scale >= 3, death, cerebral edema, hemorrhagic transformation of ischemic lesions, fever, oxygen administration, pneumonia, sepsis, urinary infection and heart failure). Results Group 1 patients had more severe strokes, with larger cerebral lesions and higher inflammatory markers, compared to the other groups. They also had a high prevalence of atrial fibrillation, prediabetes, previous stroke and previous arterial revascularizations. In this group, the highest frequencies of cerebral edema, hemorrhagic transformation, pneumonia and oxygen administration were obtained. The prevalence of dependency at discharge and in-hospital mortality were equally high in Group 1 and Group 3. However, in multivariate analyses including stroke severity, cerebral lesion diameter, leukocytes and C-reactive protein, Group 1 was only independently associated with hemorrhagic transformation (OR 2.01, 95% CI 0.99-4.07), while Group 3 was independently associated with mortality (OR 2.19, 95% CI 1.32-3.64) and disability (OR 1.70, 95% CI 1.01-2.88). Conclusions Hyperglycemic non-diabetic stroke patients had a worse prognosis than non-hyperglycemic or diabetic patients, but this group was not independently associated with mortality or disability when size, severity and inflammatory component of the stroke were accounted for
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