The use of antimicrobials in italian heavy pig fattening farms

Data on antimicrobial use (AMU) in heavy pig production (>150 kg) are limited. The aim of this study was to investigate the AMU in this production. Data from 2015 were collected for 143 fattening farms. The AMU was estimated through a treatment index per 100 days (TI100) using the defined daily dose animal for Italy (DDDAit). When possible, a comparison with the European Medicines Agency’s defined daily doses for animals (DDDvet) was performed. The median TI100 was 10.7 (range, 0.2–49.5). Group treatments represented 94.6% of overall consumption. The AMU calculated using DDDAit and DDDvet were strongly correlated (ρ = 0.976; p < 0.001). The AMU was negatively correlated with injectables use (ρ = −0.46, p < 0.001) and positively correlated with oral products (ρ = 0.21, p = 0.014), premixes (ρ = 0.26, p = 0.002), and mortality (ρ = 0.18; p = 0.027). Farm size was negatively correlated with AMU (ρ = −0.29, p < 0.001). Smaller farms were more frequently above the median TI100 (odds ratio = 2.3, 95% confidence interval = 1.2–4.7), suggesting that they may have lower biosecurity and management standards. The results of this study should provide useful insights for the development of an Italian monitoring system

Optimization study of volumetric receivers for high temperature solar plants

Nowadays, due to the growing green energy demand, one of the most promising renewable source is represented by solar radiation. Concentrated solar power (CSP) could be an excellent choice, also as alternative technology for centralized energy production at large scale. Within CSP technologies, Central Receiver Towers (CRT) are one of the most interesting applications. CRT consists of a solar tower plant, mirroring surfaces (heliostat) that concentrate sunlight on a receiver and an associated thermodynamic cycle. The solar receiver is a key element of the overall technology and converts the solar radiation into heat, delivering it to a forced flow of air. Two different typologies are investigated in this paper: a porous ceramic absorber and a hierarchical receiver patented by FBK, an independent research institute in Trento, Italy. The purpose of this work is to develop an optimization tool that may generate practical guidelines for the receiver design; this task is performed by studying the potential maximum efficiency as a function of geometry (shape and dimensions) and material properties. The core of this tool is a simplified mono-dimensional model, representing both types of receiver considered in local thermal non equilibrium. The S4 discrete-ordinates approximation is employed, requiring less computational effort and ensuring at the same time accurate simulations. Examining the porous receiver, the optimization results indicate that, with a linear variable porosity, the conversion efficiency increases, for a selected pore diameter and a given thermal conductivity. The optimization of the hierarchical receiver combines four layers, each one coupled with the following one in terms of radiative and conductive heat transfer. The results suggest that the performance is substantially influenced by the behaviour of the first layer. The efficiency can be improved by a proper balance, a better optical efficiency and an enhanced convective transport

High efficient Mewar Angithi stove testing in rural Kenya

Three billion people worldwide use biomass daily for cooking, endangering health, climate, forests and biodiversity. Extensive solutions have been proposed in the literature to reduce the wood usage by increasing the efficiency of the cooking stoves. The major challenges faced are: cultural inertia to change, budget limitation and technological sophistication. This document examines if the wood-savings achieved in Rajasthan India through Mewar Angithi (MA) insert can be replicated in rural Kenya. MA local prototype construction and testing in the field was done. Analysis of field data and heat transfer simulations were performed. The achievement of 66% savings in firewood usage indicates the feasibility of this low-cost, low-tech solution to rural areas in Kenya and eventually in the rest of the Sub-Saharan region