Vitamin E as Adjuvant in Emulsified Vaccine for Chicks

Abstract Mineral oil was partially replaced with D, L-α-tocopheryl acetate (vitamin E) in bacterial and viral inactivated emulsified vaccines. Vitamin E increased the immune response to the viral antigen (Newcastle disease virus) used but not to the bacterial antigen (Escherichia coli) when its presence in the oil phase did not exceed 30%. Inoculated vitamin E may have enhanced the immune response by interacting with the immune-competent cells involved in the inflammatory reaction that followed inoculation of emulsified vaccines

Investigation on intestinal bacterial flora and Salmonella spp. presence in organic and conventional chickens

The aim of this study was to evaluate the possible differences in the intestinal microflora composition among the different rearing systems (conventional vs organic) and the Salmonella diffusion using bacteriological techniques. The results showed that the differences between the two groups at the same age, expressed by the bacterial count, are not conclusive in showing an influence of the rearing systems. Salmonella Hadar was isolated once in caeca of conventional and once in caeca of organic ones. Though the results are preliminary and referred to a well defined geographic area in Central Italy, Salmonella detection does not seem to be common in conventional and organic chicken farms

Empirical investigation to explore potential gains from the amalgamation of Phase Changing Materials (PCMs) and wood shavings

The reduction of gained heat, heat peak shifting and the mitigation of air temperature fluctuations are some desirable properties that are sought after in any thermal insulation system. It cannot be overstated that these factors, in addition to others, govern the performance of such systems thus their effect on indoor ambient conditions. The effect of such systems extends also to Heating, Ventilation and Air-conditioning (HVAC) systems that are set up to operate optimally in certain conditions. Where literature shows that PCMs and natural materials such as wood-shavings can provide efficient passive insulation for buildings, it is evident that such approaches utilise methods that are of a degree of intricacy which requires specialist knowledge and complex techniques, such as micro-encapsulation for instance. With technical and economic aspects in mind, an amalgam of PCM and wood-shavings has been created for the purpose of being utilised as a feasible thermal insulation. The amalgamation was performed in the simplest of methods, through submerging the wood shavings in PCM. An experimental procedure was devised to test the thermal performance of the amalgam and compare this to the performance of the same un-amalgamated materials. Comparative analysis revealed that no significant thermal gains would be expected from such amalgamation. However, significant reduction in the total weight of the insulation system would be achieved that, in this case, shown to be up to 20.94%. Thus, further reducing possible strains on structural elements due to the application of insulation on buildings. This can be especially beneficial in vernacular architectural approaches where considerably large amounts and thicknesses of insulations are used. In addition, cost reduction could be attained as wood shavings are significantly cheaper compared to the cost of PCMs

“Studio teorico-sperimentale delle proprietà acustiche di pannelli fonoassorbenti trasparenti microforati

Nella correzione acustica degli ambienti confinati si può verificare l'esigenza di co-niugare buone prestazioni di fonoassorbimento con altre proprietà di carattere estetico o funzionale, quali trasparenza alla luce, durabilità nel tempo, resistenza strutturale. Una possibile soluzione si può ottenere con tecniche di microperforazione di lastre di materiale plastico trasparente, evitando quindi il ricorso a materiali porosi. Dal punto di vista acustico, i pannelli microforati si comportano come array di risonatori, caratte-rizzati, in virtù del piccolo diametro dei fori, da buone prestazioni anche in assenza di materiali fonoassorbenti nell’intercapedine: ciò è dovuto alle elevate dissipazioni visco-se e termiche che si realizzano nello strato limite all’interno dei fori. Le prestazioni fonoassorbenti dei pannelli microforati sono note, sia a livello teorico che sperimentale, da vari decenni [1]. Applicazioni integrate di pannelli trasparenti mi-croforati sono state proposte più di recente, sia in ambiente confinato [2], sia in barriere antirumore per infrastrutture di trasporto [3]. Oggi sono commercialmente disponibili rivestimenti di pareti, in alternativa ai tradizionali materiali porosi, realizzati con pan-nelli e membrane microforati. Tali soluzioni, in virtù degli spessori richiesti per ottenere prestazioni fonoassorbenti elevate (inferiori ad 1 mm), richiedono strutture portanti e hanno scarsa resistenza strutturale. Inoltre, le dimensioni (diametri dell'ordine di 0,1 mm) e il numero dei fori richiesti richiedono processi di foratura relativamente com-plessi e costosi. Nel lavoro si sono studiate, sia a livello sperimentale sia numericamente, soluzioni fonoassorbenti per ambienti confinati, ricorrendo all’impiego di configurazioni a più lastre, in grado di coniugare buone proprietà di resistenza strutturale (spessori di 1-2 mm) e semplicità di foratura (fori di diametro non inferiore ad 1 mm)

Influence of air thermohygrometric properties on mechanical draft evaporative towers: a calculation method to predict effects in power plants and refrigerating absorption machines

The paper describes a simulation model for the evaluation of heat exchanges occurring to a flow of water falling down in counterflow with humid air, during its path through a mechanical draft cooling tower. The contemporary heat transfer by evaporation and forced convection are separately taken into account, assuming simplified hypotheses such as water flow divided into spherical drops, constant relative speed between air and water and constant thermodynamic conditions of water and air through the tower. The model has been calibrated and validated through two existing evaporative towers: a small-size one serving a refrigerating absorption machine and a medium-size one connected with the condenser of a coal-fired power plant; the comparison with the well-known Merkel and Poppe models showed only slight differences on thermodynamic parameters involved in the process. The simulation predicts water outlet conditions starting from the air inlet temperature and relative humidity, once the power to be drained is fixed. The knowledge of outlet air thermohygrometric conditions allows the definition of water outlet temperature minimum value and the evaluation of the mass flow to be reintegrated for the evaporated water replacement. Since the outlet water temperature level affects the performances of plants connected with the evaporative towers, it is interesting to vary the air external conditions, investigating the repercussions on plants’characteristics. While the influence on power plants remains circumscribed to a light variation on the produced electric power, refrigerating absorption machines result more sensitive, showing considerable fluctuations of chilling power and Coefficient Of Performance (COP)

Small size absorption refrigerators: a comparison among different solutions in solar feeding applications

Absorption refrigerating machines represent an interesting alternative to compression machines, especially when waste heat or heat produced by solar energy is available; the market is beginning to propose small-size absorption machines especially designed for air conditioning in residential buildings. A recognition of small size absorption refrigerators is reported, with particular emphasis on their performances in the case that the thermal source is constituted by solar energy. The examined machines cover different chilling powers (from 4 to 15 kW) and have different working principles. The study is conducted through the data supplied by manufacturers and collected in the experimental set-up available at the Labs of the University of Perugia; different refrigerators are compared taking into account the most significant parameters such as hot source and chilled water temperature, cooling circuit characteristics, coefficient of performance, weight and dimensions. Energy and environmental advantages deriving from the solar supply are also evaluated