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In the context of “testing laboratory” one of the most important aspect to deal with is the measurement result. Whenever decisions are based on measurement results, it is important to have some indication of the quality of the results. In every area concerning with noise measurement many standards are available but without an expression of uncertainty, it is impossible to judge whether two results are in compliance or not. ISO/IEC 17025 is an international standard related with the competence of calibration and testing laboratories. It contains the requirements that testing and calibration laboratories have to meet if they wish to demonstrate that they operate to a quality system, are technically competent and are able to generate technically valid results. ISO/IEC 17025 deals specifically with the requirements for the competence of laboratories performing testing and calibration and for the reporting of the results, which may or may not contain opinions and interpretations of the results. The standard requires appropriate methods of analysis to be used for estimating uncertainty of measurement. In this point of view, for a testing laboratory performing sound power measurement according to specific ISO standards and European Directives, the measurement of uncertainties is the most important factor to deal with. Sound power level measurement, according to ISO 3744:1994 , performed with a limited number of microphones distributed over a surface enveloping a source is affected by a certain systematic error and a related standard deviation. Making a comparison of measurement carried out with different microphone arrays is difficult because results are affected by systematic errors and standard deviation that are peculiarities of the number of microphones disposed on the surface, their spatial position and the complexity of the sound field. A statistical approach could give an overview of the difference between sound power level evaluated with different microphone arrays and an evaluation of errors that afflict this kind of measurement. Despite the classical approach that tend to follow the ISO GUM this thesis present a different point of view of the problem related to the comparison of result obtained from different microphone arrays.

Leaf rust caused by Puccinia triticina is a serious disease of durum wheat (Triticum durum) worldwide. However, genetic and molecular mapping studies aimed at characterizing leaf rust resistance genes in durum wheat have been only recently undertaken. The Italian durum wheat cv. Creso shows a high level of resistance to P. triticina that has been considered durable and that appears to be due to a combination of a single dominant gene and one or more additional factors conferring partial resistance. In this study, the genetic basis of leaf rust resistance carried by Creso was investigated using 176 recombinant inbred lines (RILs) from the cross between the cv. Colosseo (C, leaf rust resistance donor) and Lloyd (L, susceptible parent). Colosseo is a cv. directly related to Creso with the leaf rust resistance phenotype inherited from Creso, and was considered as resistance donor because of its better adaptation to local (Emilia Romagna, Italy) cultivation environment. RILs have been artificially inoculated with a mixture of 16 Italian P. triticina isolates that were characterized for virulence to seedlings of 22 common wheat cv. Thatcher isolines each carrying a different leaf rust resistance gene, and for molecular genotypes at 15 simple sequence repeat (SSR) loci, in order to determine their specialization with regard to the host species. The characterization of the leaf rust isolates was conducted at the Cereal Disease Laboratory of the University of Minnesota (St. Paul, USA) (Chapter 2). A genetic linkage map was constructed using segregation data from the population of 176 RILs from the cross CL. A total of 662 loci, including 162 simple sequence repeats (SSRs) and 500 Diversity Arrays Technology markers (DArTs), were analyzed by means of the package EasyMap 0.1. The integrated SSR-DArT linkage map consisted of 554 loci (162 SSR and 392 DArT markers) grouped into 19 linkage blocks with an average marker density of 5.7 cM/marker. The final map spanned a total of 2022 cM, which correspond to a tetraploid genome (AABB) coverage of ca. 77% (Chapter 3). The RIL population was phenotyped for their resistance to leaf rust under artificial inoculation in 2006; the percentage of infected leaf area (LRS, leaf rust susceptibility) was evaluated at three stages through the disease developmental cycle and the area under disease progress curve (AUDPC) was then calculated. The response at the seedling stage (infection type, IT) was also investigated. QTL analysis was carried out by means of the Composite Interval Mapping method based on a selection of markers from the CL map. A major QTL (QLr.ubo-7B.2) for leaf rust resistance controlling both the seedling and the adult plant response, was mapped on the distal region of chromosome arm 7BL (deletion bin 7BL10-0.78-1.00), in a gene-dense region known to carry several genes/QTLs for resistance to rusts and other major cereal fungal diseases in wheat and barley. QLr.ubo-7B.2 was identified within a supporting interval of ca. 5 cM tightly associated with three SSR markers (Xbarc340.2, Xgwm146 e Xgwm344.2), and showed an R2 and an LOD peak value for the AUDPC equal to 72.9% an 44.5, respectively. Three additional minor QTLs were also detected (QLr.ubo-7B.1 on chr. 7BS; QLr.ubo-2A on chr. 2AL and QLr.ubo-3A on chr. 3AS) (Chapter 4). The presence of the major QTL (QLr.ubo-7B.2) was validated by a linkage disequilibrium (LD)-based test using field data from two different plant materials: i) a set of 62 advanced lines from multiple crosses involving Creso and his directly related resistance derivates Colosseo and Plinio, and ii) a panel of 164 elite durum wheat accessions representative of the major durum breeding program of the Mediterranean basin. Lines and accessions were phenotyped for leaf rust resistance under artificial inoculation in two different field trials carried out at Argelato (BO, Italy) in 2006 and 2007; the durum elite accessions were also evaluated in two additional field experiments in Obregon (Messico; 2007 and 2008) and in a green-house experiment (seedling resistance) at the Cereal Disease Laboratory (St. Paul, USA, 2008). The molecular characterization involved 14 SSR markers mapping on the 7BL chromosome region found to harbour the major QTL. Association analysis was then performed with a mixed-linear-model approach. Results confirmed the presence of a major QTL for leaf rust resistance, both at adult plant and at seedling stage, located between markers Xbarc340.2, Xgwm146 and Xgwm344.2, in an interval that coincides with the supporting interval (LOD-2) of QLr.ubo-7B.2 as resulted from the RIL QTL analysis. (Chapter 5). The identification and mapping of the major QTL associated to the durable leaf rust resistance carried by Creso, together with the identification of the associated SSR markers, will enhance the selection efficiency in durum wheat breeding programs (MAS, Marker Assisted Selection) and will accelerate the release of cvs. with durable resistance through marker-assisted pyramiding of the tagged resistance genes/QTLs most effective against wheat fungal pathogens.

Aims: Ripening evaluation of two different Pecorino cheese varieties ripened according either to a traditional method in plant and in cave. Different ripening features have been analyzed in order to evaluate the cave as possible ripening environment with the aim of obtaining a peculiar product which could also establish an added value to the cultural heritage of the local place in which it has been originally manufactured. Methods and Results: Chemical-physical features of Pecorino cheese have been initially analyzed into two different ripening environments and experimentations, among which: pH, weight reduction and subsequent water activity. Furthermore, the microbial composition has been characterized in relationship with the two different ripening environments, undertaking a variety of microbial groups, such as: lactic bacteria, staphylococci, yeasts, lactococci, enterobacteria, enterococci. Besides, an additional analysis for the in-cave adaptability evaluation has been the identification of biogenic amines inside the Pecorino cheese (2-phenilethylamine, putrescine, cadaverine, hystidine, tyramine, spermine and spermidine). Further analysis were undertaken in order to track the lipid profile evolution, reporting the concentration of the cheese free fatty acids in object, in relation with ripening time, environment and production. In order to analyse the flavour compounds present in Pecorino cheese, the SPME-GC-MS technique has been widely employed. As a result, it is confirmed the trend showed by the short-chain free fatty acids, that is to say the fatty acids which are mostly involved in conveying a stronger flavor to the cheese. With the purpose of assessing the protheolytic patterns of the above-mentioned Pecorino cheese in the two different ripening environments and testing methods, the technique SDS-PAGE has been employed into the cheese insoluble fraction, whereas the SDS-PAGE technique has been carried out into the cheese soluble portion. Furthermore, different isolated belonging to various microbial groups have been genotypically characterized though the ITS-PCR technique with the aim to identify the membership species. With reference to lactic bacillus the characterized species are: Lactobacillus brevis, Lactobacillus curvatus and Lactobacillus paraplantarum. With reference to lactococci the predominant species is Lactococcus lactis, coming from the employed starter used in the cheese manufacturing. With reference to enterococcus, the predominant species are Enterococcus faecium and Enterococcus faecalis. Moreover, Streptococcus termophilus and Streptococcus macedonicus have been identified too. For staphylococci the identified species are Staphyilococcus equorum, Staphylococcus saprophyfiticus and Staphylococcus xylosus. Finally, a sensorial analysis has been undertaken through on one side a consumer test made by inexperienced consumers, and on the other side through a panel test achieved by expert consumers. From such test Pecorino cheese ripened in cave were found to be more pleasant in comparison with Pecorino cheese ripened in plant. Conclusions: The proposed approach and the undertaken analysis showed the cave as preferential ripening environment for Pecorino cheese and for the development of a more palatable product and safer for consumers’ health.

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No description available.

Today the design of hydraulic and lubrication circuits is becoming more and more important. The aim of this study is to develop a methodology for the design of the lubrication circuit of an agricultural tractor. In this paper the lubrication circuit of a continuously variable transmission is analysed. Several lines of the circuit are considered and in particular the lubrication of gears is discussed. The worst possible working condition which corresponds to the highest power dissipation for each part of the transmission is determined. The model of the lubrication circuit is developed with two different software simulations (Automation Studio & Amesim). In order to check the reliability of the simulation models and to characterise the lubrication circuit, experimental tests are performed. The comparison between the values of pressure drops obtained by the models and by the experimental test, demonstrates that it is possible to use these programs for the set up of a simple model of the lubrication circuit. The calculation of oil flows necessary for a force-fed lubrication of the gears, the simulation of the circuit by commercial software, and the validation of the circuit design allow to set up a preliminary equilibrium among the pipes and a proper flow rate distribution. Optimising the circuit design in the initial phase of the project is very important. The experimental adjustment of the circuit, which is often difficult, can be simplified; time and cost production can be reduced.

In order to improve the animal welfare, the Council Directive 1999/74/EC (defining minimum standards for the welfare of laying hens) will ban conventional cage systems since 2012, in favour of enriched cages or floor systems. As a consequence an increased risk of bacterial contamination of eggshell is expected (EFSA, 2005). Furthermore egg-associated salmonellosis is an important public health problem throughout the world (Roberts et al., 1994). In this regard the introduction of efficient measures to reduce eggshell contamination by S. Enteritidis or other bacterial pathogens, and thus to prevent any potential or additional food safety risk for Human health, may be envisaged. The hot air pasteurization can be a viable alternative for the decontamination of the surface of the egg shell. Few studies have been performed on the decontamination power of this technique on table eggs (Hou et al, 1996; James et al., 2002). The aim of this study was to develop innovative techniques to remove surface contamination of shell eggs by hot air under natural or forced convection. Initially two simplified finite element models describing the thermal interaction between the air and egg were developed, respectively for the natural and forced convection. The numerical models were validated using an egg simulant equipped by type-K thermocouple (Chromel/Alumel). Once validated, the models allowed the selection of a thermal cycle with an inner temperature always lower than 55°C. Subsequently a specific apparatus composed by two hot air generators, one cold air generator and rolling cylinder support, was built to physically condition the eggs. The decontamination power of the thermal treatments was evaluated on shell eggs experimentally inoculated with either Salmonella Enteritidis, Escherichia coli, Listeria monocytogenes and on shell eggs containing only the indigenous microflora. The applicability of treatments was further evaluated by comparing quality traits of treated and not treated eggs immediately after the treatment and after 28 days of storage at 20°C. The results showed that the treatment characterized by two shots of hot air at 350°C for 8 sec, spaced by a cooling interval of 32 (forced convection), reduce the bacterial population of more than 90% (Salmonella enteritidis and Listeria monocytogenes). No statistically significant results were obtained comparing E. coli treated and not treated eggs as well as indigenous microflora treated and not treated eggs. A reduction of 2.6 log was observed on Salmonella enteritidis load of eggs immediately after the treatment in oven at 200°C for 200 minutes (natural convection). Furthermore no detrimental effects on quality traits of treated eggs were recorded. These results support the hot air techniques for the surface decontamination of table eggs as an effective industrial process.

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