Abstract
This paper presents the results of a 3D numerical investigation carried out on a Saccardo ventilation system operating in road tunnel, with the aim to improve the Performance of the ...Ventilation System, P
vs
. 1D mathematical model, here presented, has highlighted that the pitch angle and length of inflow opening are the main parameters that influence the P
vs
. The results have shown that the pitch angle of the Saccardo nozzle, influences moderately the P
vs
, instead the opening inflow lengths influence considerably the transferring of the momentum, increasing the mass flow rate. P
vs
trend vs opening inflow length shows an improvement up to 47% with respect to the reference opening inflow length.
The study aimed to evaluate the effects of linseed and oregano supplementation to the diet of goats on fatty acid profile and sensory properties of Padraccio, a typical cheese produced during spring ...through summer in the Basilicata region (southern Italy). Extruded linseed and dried oregano inflorescences were integrated in the pelleted concentrate supplementation (500 g/head per day) in 21 grazing goats that were randomly assigned, 7 per group, to the following experimental treatments: concentrate, concentrate with addition of linseed, and concentrate with addition of linseed and oregano. Pooled milk from each group was used in cheesemaking. From a nutritional perspective, integration of extruded linseed in the goat diet improved the fatty acid profile of Padraccio cheese. Moreover, the cheese from this group evidenced the highest scoring on color, flavor, texture, and overall liking.
Abstract
Thermal piping insulation of implants is crucial for heat delivery, production, collection, or storage at high temperature values. It is currently obtained by enveloping low thermal ...conductivity materials such as rockwool, fiberglass, polyurethane, polystyrene, and aerogel. However, better performances can be reached by adopting vacuum technology. In this case, conductive losses are annihilated, and the radiative heat transfer mechanism represents the only loss mechanism. Here, we compare a high vacuum-based novel solution and the traditional insulation for heat delivery applications. We propose a high vacuum- based solution consisting of an evacuated gap that surrounds the hot pipe coated by a thin aluminium foil. Experimental results using this novel solution show a fivefold reduction of the thermal radiation losses compared to the traditional solutions when in the temperature range between 100 °C and 250 °C.
Abstract
The continuously rising demand for renewable energy sources within the energy system has highlighted the need for technologies capable of mitigating the impact of renewable energy ...intermittency and addressing the generation-demand mismatch in the system. Thermal energy storage (TES) emerges as a versatile storage medium with a wide range of applications, spanning from solar energy utilization and power peak shaving to the storage of industrial waste heat. In this study, data collected from an operating commercial stratified tank are used to validate a 2-D axisymmetric CFD model. Temperature profiles are collected throughout one month with a one-minute refresh rate. The model replicating the tank is generated in COMSOL Multiphysics® and validated by emulating the registered charging phases of the real storage. The model is then employed to optimize the stratification capability of the tank, by varying the logics applied to pinpoint optimal values of both inlet water temperature and velocity. The study aims to maximize the exergetic efficiency of the system using dimensionless exergy, a parameter often utilized in literature to identify the ability of the storage to generate and preserve optimal temperature stratification. Finally, the experimental dimensionless exergy has been evaluated for the aforementioned temperature profiles.
The use of a sterilized product for washing cows' udders before milking may be useful to reduce or prevent Clostridium tyrobutyricum contamination, the main cause of the late-blowing defect in hard ...and semi-hard cheeses. The aim of this research was to evaluate the antibacterial efficacy of an experimental formula containing 15% condensed donkey milk (lysozyme content 825 mg/L). The antimicrobial activity of condensed milk was first evaluated in vitro, using the disk diffusion method, on the following microorganisms: Bacillus megaterium, Bacillus mojavensis, Clavibacter michiganensis, and Clostridium tyrobutyricum. These results were compared with the effects of 2 antibiotics, ampicillin (100 mg/mL) and kanamycin (50 mg/ mL), and a commercial pre-dipping formula. The results showed that the inhibitory activity of lysozyme from donkey milk on all the considered microorganisms was higher than that of the commercial product and similar to that of the 2 antibiotics. Next, the formula with lysozyme was compared with a commercial pre-dipping formula on 48 lactating cows (24 cows in each group). Skin tests were performed on teats before and after pre-dipping. Results showed that the formula with condensed milk significantly reduced the clostridial load detected on the skin of cows' teats before cleaning (−55.61% vs. −27.99%) and in the bulk milk of the experimental group compared with the control group with commercial product (−52.53% vs. −32.42%).
Interobserver reproducibility in the diagnosis of benign intraductal proliferative lesions has been poor. The aims of the study were to investigate the inter- and intraobserver variability and the ...impact of the addition of an immunostain for high- and low-molecular weight keratins on the variability. Nine pathologists reviewed 81 cases of breast proliferative lesions in three stages and assigned each of the lesions to one of the following three diagnoses: usual ductal hyperplasia, atypical ductal hyperplasia and ductal carcinoma in situ. Hematoxylin and eosin slides and corresponding slides stained with ADH-5 cocktail (cytokeratins (CK) 5, 14. 7, 18 and p63) by immunohistochemistry were evaluated. Concordance was evaluated at each stage of the study. The interobserver agreement among the nine pathologists for diagnosing the 81 proliferative breast lesions was fair (κ-value=0.34). The intraobserver κ-value ranged from 0.56 to 0.88 (moderate to strong). Complete agreement among nine pathologists was achieved in only nine (11%) cases, at least eight agreed in 20 (25%) cases and seven or more agreed in 38 (47%) cases. Following immunohistochemical stain, a significant improvement in the interobserver concordance (overall κ-value=0.50) was observed (P=0.015). There was a significant reduction in the total number of atypical ductal hyperplasia diagnosis made by nine pathologists after the use of ADH-5 immunostain. Atypical ductal hyperplasia still remains a diagnostic dilemma with wide variation in both inter- and intraobserver reproducibility among pathologists. The addition of an immunohistochemical stain led to a significant improvement in the concordance rate. More importantly, there was an 8% decrease in the number of lesions classified as atypical ductal hyperplasia in favor of usual hyperplasia; in clinical practice, this could lead to a decrease in the number of surgeries carried out for intraductal proliferative lesions.
Abstract
Steam is a key energy vector in the industrial sector and each application requires it at a specific pressure and temperature. In this paper the production of low pressure dry saturated ...steam for industrial use through high-vacuum flat plate solar collectors (HVFPCs) is discussed. This technology can produce steam from solar energy, hybridizing it with existing fossil powered steam generators to obtain significant energy savings and reduce
CO
2
emissions. An energy comparison using the 0-D TRNSYS® software between numerical results of different plant configurations is made, which differ in the type of dry saturated steam production device. These devices are necessary as it is not possible to produce steam directly inside collectors. Two possible steam generation methods were analysed: direct steam production, using a Flash vessel, and indirect steam production, using a Kettle reboiler. Finally, each configuration was simulated by imposing a solar field ΔT of 10 °C and 20 °C. Dynamic results show that flash vessel configurations are generally the most efficient, with the same operating parameters, compared to the configurations with Kettle reboiler. Furthermore, configurations with certain ΔT, such as to determine lower operational solar field temperatures, lead to the best results due to the higher HVFPCs’ efficiency.
Abstract
We propose an innovative flat plate hybrid Photovoltaic-Thermal system under high vacuum (HV PV-T) optimized for solar-to-thermal energy conversion. It consists of a glass cover, metallic ...vessel, and the actual PV-T device, which englobes a low-emissive Transparent Conductive Oxide (TCO), a perovskite-based PV cell, a Solar Absorber, and a copper substrate. We investigate, through a 1-D model developed in MATLAB, the performances of the proposed PV-T system, still mined by radiative losses, varying the operating temperature (T
op
) and the emittance of the TCO (
ε
TCO
) in the ranges of (25÷175) °C and (0.05÷0.45) respectively. The annual thermal and electrical productions are evaluated considering the Typical Meteorological Year of Naples, Italy. Specific annual costs and emission savings are evaluated and compared with the ones assured by commercial High Vacuum Flat Plate Solar-Thermal (HVFP ST) and PV collectors. Results indicate that the proposed HV PV-T increases the annual cost savings by 34% and 11% when compared to HVFP ST and PV collectors, respectively. Moreover, the presented HV PV-T increases the annual CO
2
emissions savings by 7% and 48% when compared to HVFP ST and PV collectors, respectively.
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