Strategies for improving the nutritional quality of milk and dairy products from different species reared in the Mediterranean area

The aim of the first trial was to evaluate the effects of flaxseed supplementation on the yield and quality of buffalo milk. In particular, the fatty acid profile of milk from buffalo cows subjected to different diets has been investigated. Although buffalo milk is the second most produced milk in the world, and of primary nutritional importance in various parts of the world, few studies have focused on the chemical properties of buffalo milk. The larger size of buffalo fat globules, 5 vs. 3.5 μm, was related to the higher amount of fat in the buffalo milks: 73.4 ± 9.9 vs. 41.3 ± 3.7 g/kg for cow milk. Buffalo milks contained significantly lower amount of polar lipids expressed per gram of lipids (0.26% vs. 0.36%), but significantly higher amount of polar lipids per litre of milk (+26%). For these reasons, considered the interesting potential of this milk and the growing need for functional products it seemed interesting to evaluate the fatty acid composition of buffalo milk obtained from a supplementation of flaxseed in the diet of animals. The experimental design provided for flaxseed supplementation to buffalo dairy cows in mid lactation. Treatments were: (1) no flaxseed supplementation (CO); (2) low flaxseed supplementation (500 g/d; FS500); (3) moderate flaxseed supplementation (1,000g/d; FS1000). Milk protein and casein were affected by flaxseed supplementation resulting lower in flaxseedsupplemented diets. Furthermore, the results revealed that flaxseed supplementation positively affected the milk fatty acids Short-chain fatty acids, in particular C8:0 and C10:0, were the lowest in milk from buffalo cows fed the highest level of flaxseed supplementation. Medium-chain fatty acids were the lowest in FS1000, intermediate in FS500. Long-chain fatty acids were the highest in FS1000, intermediate in FS500 groups, and the lowest in milk from buffalo receiving no flaxseed supplementation. Total conjugated linoleic acid content evidenced the same trend of long-chain fatty acids, with an increase of about 7% in FL500 and of 22% in FL1000 than the control. Atherogenic index, thrombogenic index, and n-6/n-3 were the lowest in FS1000 groups; thrombogenic index and n-6/n-3 were intermediate in milk from animals receiving FS500. Nutritional value of the acidic profile in buffalo milk is influenced by flaxseed supplementation, and its improvement reflects the level of dietary flaxseed supplementation. The objective of this second trial of PhD thesis is to evaluate the sensory profile and consumers’ liking of functional ovine cheese containing probiotic cultures, also observing the action of different strains of probiotic, added to rennet paste for cheesemaking, to assess their ability to produce conjugated linoleic acid (CLA) from free linoleic acid (LA) and Free Amino Acids (FAA), able to positively influence the nutritional and organoletic quality of the cheese. Probiotic are defined as “live microorganisms that, when administred in adeguate amounts, confer a health benefit on the host” (Food and Agricuture Organization of United Nations; World Health Organization-FAO/WHO, 2001). The sensory perception of a food is a very important product characteristic; it is a complex process, which is influenced by many factors, such as content of flavour compounds, the texture, and appearance of the product, but also several characteristics of the individual consuming the product in a certain environment. Aroma development in cheese products is influenced by metabolic activities of cheese bacteria, glycolysis, lipolysis and proteolysis. Flavor compounds in cheese arise from the action of enzymes, from the rennet (substitute), the milk, the (secondary) starter and non-starter bacteria, together with non-enzymatic conversions (Walstra et al., 1993; Kosikowski et al., 1997; Skeie et al., 2000). In cheese making, selected starter cultures are of main importance for controlling flavor formation. In order to respond to the increasing demand for products with improved aroma characteristics, the use of bacterial strains for cheese ripening is considered a very promising method. Ovine cheese was made from ewe’s milk by animals reared in extensive conditions; cheesemaking trials were performed by using rennet paste containing probiotic cells. The experimental test was conducted in a cattle farm where animals (Gentile di Puglia sheep) were reared with a semiextensive system, that provides for the integration of the food ration with concentrated in autumn and winter months. The experimental cheeses are produced using three different rennet pastes lamb rennet in traditional lamb pasta (cheese thus obtained was called cheese control-C), rennet paste lamb containing a mix of Bifidobacterium lactis and Bifidobacterium longum (BB), and cheese manufactured using lamb rennet paste containing Lactobacillus acidophilus (LA).Three experimental cheesemaking were performed for each type of rennet. The rennet had a content of chymosin: pepsin of at 80:20. The probiotic micro-organisms have been incorporated in the rennet paste 24h before each job in a concentration of 109 cfu / g of rennet. The average cell count of probiotic bacteria in the experimental cheese was found to be 7,4x107ufc / g and 7,1x107ufc / g in LA and BB cheeses, respectively, at the end of the vesting period. The cell counts show that the production of cheese from sheep's milk pecorino probiotic Gentile di Puglia was conducted successfully. In the literature it is reported that the minimum dose of probiotics able to really play a beneficial effect on the health of the host is of 108-109 cfu / ml which corresponds to the assumption of 100-g of product containing 106-107 cfu / ml per day (Lourens- Hattingh, 2001). Ovine cheese containing probiotic strains highlighted a more intense proteolysis and a greater level of short chain free fatty acids and conjugated linoleic acid due to the metabolic activity of the adjunct microflora. The sensorial profile of ovine cheese showed lower humidity and gumminess in cheeses containing probiotics as a consequence of differences in the maturing process; furthermore, probiotic cheeses scored higher ratings for salty and pungent attributes. An interaction effect of probiotic, gender, and age of the consumers was detected in the perceived and the expected liking. The higher rate of expected liking in all experimental cheeses is attributed to the information given, regarding not only the presence of probiotic strains but also the farming conditions and cheesemaking technology

Estimation of the dissipative heat sources related to the total energy input of a cfrp composite by using the second amplitude harmonic of the thermal signal

Theories for predicting the fatigue behaviour of composite laminates often make strong assumptions on the damage mechanisms that strongly depend on the designed laminate lay-up. In this regard, several physical and empirical models were proposed in the literature that generally require experimental validations. The experimental techniques, such as thermography, also provide useful tools for monitoring the behaviour of the specific material so, that they can be used to support the study of the damage mechanisms of materials. In this research, the second amplitude harmonic of the thermal signal has been investigated and used to assess the relationship with the total energy input in order to estimate the fatigue strength of the material. A thermal index was assessed by monitoring the constant amplitude tests (S/N curve) that were performed on a quasi-isotropic carbon fibre reinforced polymer (CFRP) laminate obtained by the automated fibre placement process. The obtained results demonstrated the capability of the second amplitude harmonic of the thermal signal to describe and monitor the fatigue damage

Study of the plastic behavior around the crack tip by means of thermal methods

AbstractIn this work, the behaviour of two cracked stainless steel AISI 410 and C3FM was studied by means of a new procedure based on thermographic methods. A temperature model in time domain was considered in order to obtain information about the first and the second order harmonic of the temperature signal. Interesting results were obtained in term of possibility to describe the plastic phenomena at the crack tip

Study of damage of t-joint components by using different non-destructive techniques

The present research is focused on the use of different non-destructive techniques for detecting damage in CFRP composite structures obtained by an innovative technological process: Automated Fiber Placement. The component was a T-joint stringer adhesively bonded to a skin panel. The aim of the present work is to show the capability of these techniques to provide complementary information for detecting the damage in composites. Automated Fibre Placement consists in an automatic deposing of prepeg or dry plies on a specific mould. The innovation lies in the possibility to reduce the time of the manufacturing process of large and complex structures by using a robotic arm that contemporary deposes fibre tows and pre-polymerizes them. The resulting products present higher quality in terms of surface finish, internal flaws absent and higher mechanical properties. The T-joint component tested in the present research was addressed to both static and cyclic tests. After the damage was induced in the material it was performed a qualitative and quantitative study of the damage by using different nondestructive techniques: Thermoelastic stress analysis (TSA), Ultrasound tests (UT) and displacement/strain measurements provided by strain gages. Processing and post-processing procedures were developed to analyze the data from each tests and finally the comparison of the results allowed a complete characterization and an overview of damage in the component by observing specifically where and when it occurred and how many regions of the component were interested. Finally, dimension, shape and depth where assessed

Influence of Second-Order Effects on Thermoelastic Behaviour in the Proximity of Crack Tips on Titanium

The Stress Intensity Factor (SIF) is used to describe the stress state and the mechanical behaviour of a material in the presence of cracks. SIF can be experimentally assessed using contactless techniques such as Thermoelastic Stress Analysis (TSA). The classic TSA theory concerns the relationship between temperature and stress variations and was successfully applied to fracture mechanics for SIF evaluation and crack tip location. This theory is no longer valid for some materials, such as titanium and aluminium, where the temperature variations also depend on the mean stress. The objective of this work was to present a new thermoelastic equation that includes the mean stress dependence to investigate the thermoelastic effect in the proximity of crack tips on titanium. Westergaard’s equations and Williams’s series expansion were employed in order to express the thermoelastic signal, including the second-order effect. Tests have been carried out to investigate the differences in SIF evaluation between the proposed approach and the classical one. A first qualitative evaluation of the importance of considering second-order effects in the thermoelastic signal in proximity of the crack tip in two loading conditions at two different loading ratios, R = 0.1 and R = 0.5, consisted of comparing the experimental signal and synthetic TSA maps. Moreover, the SIF, evaluated with the proposed and classical approaches, was compared with values from the ASTM standard formulas. The new formulation demonstrates its improved capability for describing the stress distribution in the proximity of the crack tip. The effect of the correction cannot be neglected in either Williams’s or Westergaard’s model

On the fatigue response of a bonded repaired aerospace composite using thermography

Lock-in thermography was employed to investigate the repair efficiency of a bonded repaired aerospace composite subjected to step-wise cycling mechanical loading. The studied component (substrate) was artificially damaged with a 5 mm circular notch and subsequently repaired with a tapered bonded patch. Critical and sub-critical damage of the repaired component was monitored via thermography during 5 Hz tension–tension fatigue. The examination of the acquired thermographs enabled the identification of the patch debonding propagation as well as the quantification of the stress magnification at the patch ends and the locus of the circular notch. It was found that fatigue mechanical loading yields both thermoelastic and hysterestic phenomena with the latter being more prominent prior to the failure of the studied repaired component

Guida rapida alla direzione dei lavori dopo il codice appalti 2016 : quadro normativo, requisiti, incarico, compensi e attività del direttore dei lavori alla luce del D. Leg.vo 18/04/2016, n. 50, e delle linee guida Anac sui servizi tecnici e sul Rup, con memorandum operativo per l’esecuzione di opere pubbliche

Questo testo tratta l’attività della direzione dei lavori e costituisce una guida operativa, che fissa i punti essenziali e pone l’attenzione sui principali aspetti metodologici e operativi, districandosi tra quanto previsto nel D. Leg.vo 50/2016, nelle norme ancora in vigore del D.P.R. 207/2010 (regolamento attuativo del Codice ora quasi integralmente abrogato dal D. Leg.vo 50/2016) nonché nei provvedimenti attuativi e nelle linee guida emanate dall’Anac. Sono trattati i requisiti, l’incarico, i compensi e le responsabilità del direttore dei lavori nonché dei suoi assistenti e collaboratori, i suoi rapporti con il responsabile del procedimento e con le imprese e tutte le attività da svolgere. Viene inoltre presentato un completo e dettagliato memorandum esecutivo, che mette in luce tutte le fasi dello svolgimento dell’incarico, da quelle prodromiche all’incarico ed all’avvio del cantiere, fino alla fine dei lavori. Si tratta pertanto di un prezioso supporto a disposizione dei professionisti incaricati della direzione esecutiva di opere e lavori pubblici e di coloro che operano nel relativo ufficio, chiamati a conoscere ed applicare una copiosa e spesso contraddittoria produzione legislativa

Service design for cultural intangible heritage: tra conoscenza dell’architettura contemporanea e turismo sostenibile il caso di Matosinhos.

Questo lavoro nasce dal desiderio di approfondire alcuni aspetti della vita legati alle architetture della città, a seguito della mia esperienza di ricerca di tesi svoltasi in Portogallo, nello specifico a Matosinhos, presso la fondazione Casa da Arquitectura

Estimation of the Dissipative Heat Sources Related to the Total Energy Input of a CFRP Composite by Using the Second Amplitude Harmonic of the Thermal Signal

Theories for predicting the fatigue behaviour of composite laminates often make strong assumptions on the damage mechanisms that strongly depend on the designed laminate lay-up. In this regard, several physical and empirical models were proposed in the literature that generally require experimental validations. The experimental techniques, such as thermography, also provide useful tools for monitoring the behaviour of the specific material so, that they can be used to support the study of the damage mechanisms of materials. In this research, the second amplitude harmonic of the thermal signal has been investigated and used to assess the relationship with the total energy input in order to estimate the fatigue strength of the material. A thermal index was assessed by monitoring the constant amplitude tests (S/N curve) that were performed on a quasi-isotropic carbon fibre reinforced polymer (CFRP) laminate obtained by the automated fibre placement process. The obtained results demonstrated the capability of the second amplitude harmonic of the thermal signal to describe and monitor the fatigue damage