optimization of solar integration in biomass fuelled steam plants

Abstract This paper is focused on solar-biomass integration and presents a thermodynamic analysis of solar power utilization replacing the steam bleeds of a regenerative Hirn cycle plant, biomass fuelled, in feedwater pre heating process. In solar-biomass integrated configuration an energy conversion efficiency of solar energy has been evaluated in order to compare the use of solar energy in solo and hybrid configurations. Such efficiency has been adopted as optimization parameter for the best hybrid plant configuration, varying steam pressure and regeneration parameters

Advanced Image Analysis of Two-Phase Flow inside a Centrifugal Pump

The analysis two-phase flow inside centrifugal pumps is a fundamental issue in several engineering applications. This often represents a bad working condition with respect to single phase one, causing head reduction, efficiency decrease, and higher operational costs in terms of energy and money. The paper reports a numerical analysis of bubbles behavior inside centrifugal pumps. Equations regulating the air bubble motion within the rotor of a centrifugal pump have been solved considering the effects of all forces acting. Coalescence phenomena have been investigated too, in order to identify how gas zone presence in the rotor can lead to anomalous working condition. Results are reported in graphs and diagrams varying bubble dimension and water flow rate. An experimental approach to visualize the two-phase flow field inside the impeller is presented too. Images have been acquired, elaborated, compared with numerical results, and discussed in order to understand the interaction between gas phase and liquid phase and to correlate this behavior with the energy dissipation phenomena for a centrifugal pump

Damage and energy absorption in GFRP laminates impacted at low-velocity: Indentation model

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Neuronal nitric oxide synthase (NOS I) in the buffalo epididymis

The localization of neuronal nitric oxide (NOS I) in the buffalo epididymis have been investigated by nicotinamide adenite dinucleotide phosphatase-diaphorase (NADPH-d) histochemichemistry to the light microscope (LM) and NOS immunoistochemistry to the scanning electron microscope (SEM), respectively. Histochemistry: examination of epididymis specimens revealed an intense NADPH-d staining in the basal cell epithelium and endothelium cells of blood vessel. The NADPH diaphorase staining was diffuse and granular only along the caput epididymal epithelium. NADPH diaphorase staining was less intense or absent in the corpus and in the cauda of epididymis. Dense NADPH diaphorase is labeling in the endothelium of blood vessels along the whole buffalo epididymis. Immunoistochemistry: intense NOS I immunoreactivity was detected in the caput epididymis specimen by immuno-SEM. The basal epithelium showed intense and wide-spread immunoreactivity. In the corpus and in the cauda of the epididymis not observed NOS I immunoreactivity. The specific localization of NOS I in buffalo epididymis suggest that nitric oxide may be involved to explain epididymal function: maturation and storage

Numerical, Experimental and Analytical Correlation for Predicting the Structural Behavior of Composite Structures under Impact

Abstract In the present work, numerical, experimental and analytical results regarding impact events on composite structure are presented. The test case consists in a classic 24 plies CAI specimen (100×150 mm) subjected to 10 J impact. The work can be divided into two phases. The first phase is finalized to the definition of a procedure able to provide a robust numerical model, which can simulate accurately the structural response of composite plates subjected to impact events. At this phase, the numerical results are compared with analytical ones. In the second phase, both inter- and intra-lamina failure are considered. Regarding the inter-laminar failure, an experimental-numerical procedure is defined in order to set the right parameters related to cohesive behaviour. For both phases, trade-off analyses on the main numerical parameters are performed. All numerical results are compared with experimental ones in terms of both energy balance and damaged area

Heterologous production of human papillomavirus type-16 L1 protein by a lactic acid bacterium

<p>Abstract</p> <p>Background</p> <p>The expression of vaccine antigens in lactic acid bacteria (LAB) is a safe and cost-effective alternative to traditional expression systems. In this study, we investigated i) the expression of Human papillomavirus type 16 (HPV-16) L1 major capsid protein in the model LAB <it>Lactococcus lactis </it>and ii) the ability of the resulting recombinant strain to produce either capsomer-or virus-like particles (VLPs).</p> <p>Results and conclusion</p> <p>HPV-16 L1 gene was cloned into two vectors, pCYT and pSEC, designed for controlled intra- or extracellular heterologous expression in <it>L. lactis</it>, respectively. The capacity of <it>L. lactis </it>harboring either pCYT:L1 or pSEC:L1 plasmid to accumulate L1 in the cytoplasm and supernatant samples was confirmed by Western blot assays. Electron microscopy analysis suggests that, L1 protein produced by recombinant lactococci can self-assemble into structures morphologically similar to VLPs intracellularly. The presence of conformational epitopes on the <it>L. lactis</it>-derived VLPs was confirmed by ELISA using an anti-HPV16 L1 capsid antigen antibody. Our results support the feasibility of using recombinant food-grade LAB, such as <it>L. lactis</it>, for the production of L1-based VLPs and open the possibility for the development of a new safe mucosal vector for HPV-16 prophylactic vaccination.</p

conventional orthogonal cutting machining on unidirectional fibre reinforced plastics

Abstract The results of orthogonal cutting tests on unidirectional carbon and glass fibre reinforced plastics are presented. The specimens were under shape of rectangular plates, circular disks and cylinders with different fibre architectures and a milling machine, a lathe machine and a five-axis high-speed vertical machining centre, were used for the experimental tests. The cutting speed was varied. During the tests, performed at low cutting speed, avoiding thermal effects, and high speed, to investigate about the effect of the cutting velocity on the cut quality, the fibre orientation respect to the cutting direction, the tool rake angle and the depth of cut were varied to investigate their influence on the phenomenon. A high speed steel tool in different geometries, was used. The mechanisms of chip formation and the cutting quality were investigated. A tentative to correlate the mechanisms of chip formation and cutting forces signals was done. Since the anisotropy, the mechanisms of chip formation consists of different failure modes occurring simultaneously and their identification, on the basis of the cutting force evolution, is very complex. Only in particular conditions, the features of cutting forces allow a precise identification of the chip development and detachment. The results indicated that the fibre orientation respect to the cutting direction determines the mechanisms of chip formation and influences the cutting quality. It was noted that for fibre orientation higher than 60°, the quality of the surface was revealed unacceptable. These conclusions were obtained independently of the particular shape of specimen tested and of the speed adopted

Andic soils and catastrophic mudflows in Italy: morphological and hydropedological evidences

In Italy rapid landslides are the most frequently occurring natural disasters and, after earthquakes, cause the highest number of victims. In this contribution we attempt to prove that there exist a tight connection between the presence of a specific soil type, namely andic soils, and the occurrence of the main catastrophic mudflows and debris flows occurred in Italy in the last decades. The study was performed by means of an integrated pedological and hydrological analysis on the detachment crowns of some of the most important catastrophic mudflows and debris flows occurred in Italy in the last decades and involving/evolving surface soils. The results at both regional (Campania) and National (Italy) scale clearly show that despite the large variability of the environmental settings of the studied sites there are indeed some striking homogeneous soil features in the detachment crowns including (i) soil morphology, (ii) andic features ranging from high to moderate, (iii) high water retention throughout a large range of pressure heads. Results seem to reveal clear cause-effect evidences between andic soils and the investigated catastrophic mudflows/debrisflows; this must be related to the unique physical properties of these soils inducing high landslide vulnerability

Lactococci and lactobacilli as mucosal delivery vectors for therapeutic proteins and DNA vaccines

Food-grade Lactic Acid Bacteria (LAB) have been safely consumed for centuries by humans in fermented foods. Thus, they are good candidates to develop novel oral vectors, constituting attractive alternatives to attenuated pathogens, for mucosal delivery strategies. Herein, this review summarizes our research, up until now, on the use of LAB as mucosal delivery vectors for therapeutic proteins and DNA vaccines. Most of our work has been based on the model LAB Lactococcus lactis, for which we have developed efficient genetic tools, including expression signals and host strains, for the heterologous expression of therapeutic proteins such as antigens, cytokines and enzymes. Resulting recombinant lactococci strains have been tested successfully for their prophylactic and therapeutic effects in different animal models: i) against human papillomavirus type 16 (HPV-16)-induced tumors in mice, ii) to partially prevent a bovine β-lactoglobulin (BLG)-allergic reaction in mice and iii) to regulate body weight and food consumption in obese mice. Strikingly, all of these tools have been successfully transposed to the Lactobacillus genus, in recent years, within our laboratory. Notably, anti-oxidative Lactobacillus casei strains were constructed and tested in two chemically-induced colitis models. In parallel, we also developed a strategy based on the use of L. lactis to deliver DNA at the mucosal level, and were able to show that L. lactis is able to modulate the host response through DNA delivery. Today, we consider that all of our consistent data, together with those obtained by other groups, demonstrate and reinforce the interest of using LAB, particularly lactococci and lactobacilli strains, to develop novel therapeutic protein mucosal delivery vectors which should be tested now in human clinical trials