Integration of Renewable Energy Systems at City Gate Stations to Reduce Pre-Heating Gas Consumption

The Italian Natural Gas (NG) distribution network includes thousands of NG metering and pressure reduction stations, called City Gate Stations (CGS), for injecting gas into low-pressure networks. These plants are mainly based on the isenthalpic throttling of the gas flow to reduce its pressure, which leads to a significant reduction of its temperature by the Joule-Thompson effect. Gas preheating systems that avoid excessive cooling are installed upstream of pressure reduction valves and usually exploit conventional gas boilers. The energy consumption and carbon footprint could be reduced by integrating heat pumps coupled with renewable energy sources for NG preheating to support gas boilers. For this work, an ad-hoc thermodynamic model for estimating the thermal energy demand for pre-heating is developed, exploiting experimental data from a real CGS, and simplified models of heat pumps and renewable systems. This work aims to assess the actual technical and economic feasibility of energy savings through these technologies. Results show the validated model to be sufficiently accurate to estimate the need for gas preheating for these applications. For the considered case study, up to 38%, 32%, or 26% of the total thermal energy can be recovered with a PBT of less than 20 years, 15, and about 13 years, respectively

Ultrastructural analysis of collagen fibril diameter distribution in cleft lip

Objective: A preliminary study to determine collagen fibril diameter (CF-ED) distribution on medial and lateral sides of cleft lip (CL). Material and Methods: Tissue samples from medial and lateral sides of CL were fixed in 2.5% glutaraldehyde and 1% osmium tetroxide and embedded in Araldite CY212 resin for transmission electron microscopy. The analysis of CF-ED was performed using the ImageJ program. To characterize the packaging of collagen fibrils (CFs) in the two tissues, we estimated the collagen number density (CF-ND) and fibril-area-fraction (FAF). Differences in measurements across the two sides were calculated using Wilcoxon signed-rank test. Results: The CF-ED was statistically significantly (p < 0.001) smaller on the medial side (45.69 ± 7.89 nm) than on the lateral side (54.18 ± 7.62 nm). The medial side had a higher CF-ND and a higher percentage of FAF than the lateral side. Conclusion: Our finding of a smaller CF-ED and higher CF-ND and FAF for the medial side suggests possible differences in size and distribution of CFs between medial and lateral sides of CL. This finding provides knowledge toward underlying tissue biomechanics that may help reconstruction of perioral tissue scaffolds, ultimately resulting in better treatment of patients with oral clefts

LINE-1 methylation in cleft lip tissues:influence of infant MTHFR c.677C&gt;T genotype

Objective: To investigate the influence of MTHFR c.677C&gt;T genotype on LINE-1 methylation in lateral and medial tissues from cleft lip (CL). Methods: Forty-five consecutive non-syndromic cleft lip with or without cleft palate (nsCL/P) cases were included in the study. Genomic DNA was extracted from tissues at both sides of cleft lip, and LINE-1 methylation was detected by bisulfite conversion and pyrosequencing. MTHFR c.677C&gt;T genotyping was carried out using the TaqMan genotyping assay. Results: LINE-1 methylation level was significantly higher on medial side of cleft lip compared with lateral side (p&nbsp;=&nbsp;0.001). This difference was not significantly influenced by the case's sex or cleft type. However, MTHFR c.677C&gt;T genotyping revealed that the difference in LINE-1 methylation across cleft lip was restricted to carriers of C allele of MTHFR c.677C&gt;T and was not apparent in TT homozygous cases (p&nbsp;=&nbsp;0.027). Conclusion: This integrated analysis supports the previous finding of differences in DNA methylation across the two sides of cleft lip and further suggests a possible role of MTHFR c.677C&gt;T genotype in establishing this difference