Measurements and modeling of piston temperature in a research compression ignition engine during transient conditions

Abstract The knowledge of piston temperature during internal combustion engine operation represents a precious information to evaluate heat losses and engine efficiency. Experimental measurements of piston temperature during engine functioning is very challenging; hence, modeling this process can be very helpful. In the present work, temperature measurements have been collected using a research compression ignition engine, both in motored and fired mode. They have been used to set-up a 1d model of heat transfer through the piston optical window. A good agreement has been obtained. Moreover, the model can provide information not available from experiments

Diagnostiche non convenzionali per l’analisi del processo di iniezione in un motore monocilindrico ad accensione per compressione - Non conventional diagnostics of injection process in single cylinder compression ignition engine

This thesis has been carried out in the Istituto Motori – CNR of Napoli. The mission of the institute is the research on engines and other kinds of propellers for the development of the future transport systems. The main targets of the research activities concern the reduction of pollutant emissions and fuel consumption of modern engines. A variety of experimental and numerical activities are carried out in the institute with the aim to understand the entire functioning chain of internal combustion engines. The research activities of the present doctoral thesis have been run in the optical diagnostics laboratory. In particular, the present work focuses on the analysis of the injection process in a single-cylinder compression ignition engine via direct imaging with high speed cameras. The research engine is derived from a light duty production engine and is fed with commercial Italian diesel fuel. The engine performances have been analyzed in seven operating conditions that are representative of the engine behavior during the homologation cycle New European Driving Cycle (NEDC) when installed on a D-class vehicle. The approach used in this work for the investigation of in-cylinder processes is based on the combination of experimental activities and numerical simulations. A mono-dimensional (1d) model developed by the Sandia National Laboratories to simulate the fuel injection in a control volume combustion vessel has been implemented and adjusted to fit in-cylinder thermodynamic conditions and geometrical limitations. The model has been set up using experimental data collected on the single-cylinder optical engine. The thermodynamic parameters have been collected in conjunction to images of the injection process in the visible range. A sensitivity analysis to the model input values has been made and by comparing the model result to injection images it has been possible to understand the model limitations and potentialities. It has revealed to work well for the simulation of the injection process inside the engine and could provide additional information to the investigated phenomena. For example, the jet/wall interaction has been investigated and the fuel mass impinging on the combustion chamber wall has been correlated to the exhaust emissions of particulate matter (PM). Moreover, the model has been able to provide both the penetrations of the liquid and vapor fuel. Whereas visible imaging of the injection process could provide only images of the fuel liquid phase, it could be very useful to get information about the vapor phase too. The 1d model has revealed to be a valid support for the development of a novel optical technique for the visualization of the vapor fuel using infrared imaging. As aforementioned, visible imaging is able to detect only the fuel liquid phase; for the visualization of the fuel vapor phase there exist several optical techniques characterized by complex set up and high sensitivity to fuel impurities and geometrical limitations. On the contrary, infrared imaging is able to overcome the limitations of the previous diagnostics. For this reason, this technique has been setup and applied for the optical diagnostics in the single-cylinder research engine. The spectral analysis in the range 1.5-5 μm allowed to identify two wavelengths to investigate: at 3.4 μm and at 3.9 μm. The penetration curves obtained from the infrared images have been compared to the ones from visible images and from the model (liquid and vapor penetrations). The two selected wavelength, 3.4 μm and 3.9 μm, demonstrated to be good for the visualization in the infrared of the vapor and liquid phase, respectively. According to these observations, a more accurate analysis of the infrared radiation of the fuel jets and the modeled fuel evaporation rate allowed to understand better the fuel vaporization process. The results reported in this doctoral thesis, the description of the 1d model of fuel injection inside the engine, and the presentation of an innovative optical technique in the infrared for the detection of the fuel vapor phase could contribute to the present scientific context for the development of sustainable transport systems with low environmental impact

Omics-based monitoring of microbial dynamics across the food chain for the improvement of food safety and quality

The diffusion of high-throughput sequencing has dramatically changed the study of food microbial ecology. Amplicon-based description of the microbial community may be routinary implemented in the food industry to understand how the processing parameters and the raw material quality may affect the microbial community of the final product, as well as how the community changes during the shelf-life. In addition, application of shotgun metagenomics may represent an invaluable resource to understand the functional potential of the microbial community, identifying the presence of spoilage-associated activities or genes related to pathogenesis. Finally, retrieving Metagenome-Assembled Genomes (MAGs) of relevant species may be useful for strain-tracking along the food chain and in case of food poisoning outbreaks. This review gives an overview of the possible applications of sequencing-based approaches in the study of food microbial ecology, highlighting limitations that still prevent the spreading of these techniques to the food industry

Assembly of the Auditory Circuitry by a Hox Genetic Network in the Mouse Brainstem

Rhombomeres (r) contribute to brainstem auditory nuclei during development. Hox genes are determinants of rhombomere-derived fate and neuronal connectivity. Little is known about the contribution of individual rhombomeres and their associated Hox codes to auditory sensorimotor circuitry. Here, we show that r4 contributes to functionally linked sensory and motor components, including the ventral nucleus of lateral lemniscus, posterior ventral cochlear nuclei (VCN), and motor olivocochlear neurons. Assembly of the r4-derived auditory components is involved in sound perception and depends on regulatory interactions between Hoxb1 and Hoxb2. Indeed, in Hoxb1 and Hoxb2 mutant mice the transmission of low-level auditory stimuli is lost, resulting in hearing impairments. On the other hand, Hoxa2 regulates the Rig1 axon guidance receptor and controls contralateral projections from the anterior VCN to the medial nucleus of the trapezoid body, a circuit involved in sound localization. Thus, individual rhombomeres and their associated Hox codes control the assembly of distinct functionally segregated sub-circuits in the developing auditory brainstem

Specific Microbial Communities Are Selected in Minimally-Processed Fruit and Vegetables according to the Type of Product

Fruits and vegetables (F&V) products are recommended for the daily diet due to their low caloric content, high amount of vitamins, minerals and fiber. Furthermore, these foods are a source of various phytochemical compounds, such as polyphenols, flavonoids and sterols, exerting antioxidant activity. Despite the benefits derived from eating raw F&V, the quality and safety of these products may represent a source of concern, since they can be quickly spoiled and have a very short shelf-life. Moreover, they may be a vehicle of pathogenic microorganisms. This study aims to evaluate the bacterial and fungal populations in F&V products (i.e., iceberg lettuces, arugula, spinaches, fennels, tomatoes and pears) by using culture-dependent microbiological analysis and high-throughput sequencing (HTS), in order to decipher the microbial populations that characterize minimally-processed F&V. Our results show that F&V harbor diverse and product-specific bacterial and fungal communities, with vegetables leaf morphology and type of edible fraction of fruits exerting the highest influence. In addition, we observed that several alterative (e.g., Pseudomonas and Aspergillus) and potentially pathogenic taxa (such as Staphylococcus and Cladosporium) are present, thus emphasizing the need for novel product-specific strategies to control the microbial composition of F&V and extend their shelf-life

Specific Microbial Communities Are Selected in Minimally-Processed Fruit and Vegetables according to the Type of Product

Fruits and vegetables (F&V) products are recommended for the daily diet due to their low caloric content, high amount of vitamins, minerals and fiber. Furthermore, these foods are a source of various phytochemical compounds, such as polyphenols, flavonoids and sterols, exerting antioxidant activity. Despite the benefits derived from eating raw F&V, the quality and safety of these products may represent a source of concern, since they can be quickly spoiled and have a very short shelf-life. Moreover, they may be a vehicle of pathogenic microorganisms. This study aims to evaluate the bacterial and fungal populations in F&V products (i.e., iceberg lettuces, arugula, spinaches, fennels, tomatoes and pears) by using culture-dependent microbiological analysis and high-throughput sequencing (HTS), in order to decipher the microbial populations that characterize minimally-processed F&V. Our results show that F&V harbor diverse and product-specific bacterial and fungal communities, with vegetables leaf morphology and type of edible fraction of fruits exerting the highest influence. In addition, we observed that several alterative (e.g., Pseudomonas and Aspergillus) and potentially pathogenic taxa (such as Staphylococcus and Cladosporium) are present, thus emphasizing the need for novel product-specific strategies to control the microbial composition of F&V and extend their shelf-life

Advanced Virgo: Status of the Detector, Latest Results and Future Prospects

none6noopenBersanetti, Diego; Patricelli, Barbara; Piccinni, Ornella Juliana; Piergiovanni, Francesco; Salemi, Francesco; Sequino, ValeriaBersanetti, Diego; Patricelli, Barbara; Piccinni, Ornella Juliana; Piergiovanni, Francesco; Salemi, Francesco; Sequino, Valeri

Design of bioactive biopolymer coating based on Latilactobacillus curvatus 54M16 producer of bacteriocins to preserve the safety of minimally processed fennel

In this study Latilactobacillus curvatus 54M16 (LAB) producing bacteriocins has been incorporated into a sodium caseinate (SC)/guar gum (GG)/beeswax (BW) blend to develop a bioactive film/coating. Moreover, the coating capacity of preserving the safety and quality of minimally processed fennel has been investigated. Results showed significant antimicrobial activity of the bioactive film against L. innocua C6 during 28 days of storage at 4 ◦C, 10 ◦C, 20 ◦C and 30 ◦C. The presence of LAB did not affect the moisture content, thickness, color, and solubility of the SC/GG/BW films, whereas caused a reduction of the film’s stiffness and water vapor permeability. Counts of L. innocua on fennels processed with the active coating showed a significant reduction of about 2 log cycles at the end of storage with respect to the control samples for which L. innocua ranged from 3.42 to 4.13 log CFU/cm2 . Moreover, microbial diversity dramatically decreased in samples coated with antimicrobial film, that were dominated by Lactobacillus sp. In conclusion, the developed bioactive coating can be used as an antimicrobial coating to improve minimally processed fennel safet

Evidence of virulence and antibiotic resistance genes from the microbiome mapping in minimally processed vegetables producing facilities

Daily consumption of fresh vegetables is highly recommended by international health organizations, because of their high content of nutrients. However, fresh vegetables might harbour several pathogenic microorganisms or contribute to spread antibiotic resistance, thus representing a hazard for consumers. In addition, little is known about the transmission routes of the residential microbiome from the food handling environment to vegetables. Therefore, we collected environmental and food samples from three manufactures producing fresh vegetables to estimate the relevance of the built environment microbiome on that of the finished products. Our results show that food contact surfaces sampled after routine cleaning and disinfection procedures host a highly diverse microbiome, including pathogens such as the enterotoxigenic Bacillus cereus sensu stricto. In addition, we provide evidence of the presence of a wide range of antibiotic resistance and virulence genes on food contact surfaces associated with multiple taxa, thus supporting the hypothesis that selection of resistant and pathogenic taxa might occur on sanitized surfaces. This study also highlights the potential of microbiome mapping routinely applied in food industries monitoring programs to ensure food safety

Serum KL-6 could represent a reliable indicator of unfavourable outcome in patients with COVID-19 pneumonia

KL-6 is a sialoglycoprotein antigen which proved elevated in the serum of patients with different interstitial lung diseases, especially in those with a poorer outcome. Given that interstitial pneumonia is the most common presentation of SARS-CoV2 infection, we evaluated the prognostic role of KL-6 in patients with COVID-19 pneumonia. Patients with COVID-19 pneumonia were prospectively enrolled. Blood samples were collected at the time of enrolment (TOE) and on day 7 (T1). Serum KL-6 concentrations were measured by chemiluminescence enzyme immunoassay using a KL-6 antibody kit (LUMIPULSE G1200, Fujirebio) and the cut-off value was set at > 1000 U/mL. Fifteen out of 34 enrolled patients (44.1%) died. Patients with unfavourable outcome showed significantly lower P/F ratio and higher IL-6 values and plasmatic concentrations of KL-6 at TOE compared with those who survived (median KL-6: 1188 U/mL vs. 260 U/mL, p 1000 U/mL resulted independently associated with death (aOR: 11.29, p 1000 U/mL resulted independently associated with death and showed good accuracy in predicting a poorer outcome. KL-6 may thus represent a quick, inexpensive, and sensitive parameter to stratify the risk of severe respiratory failure and death