Experimental and model validation of a phase change material heat exchanger integrated into a real building

Latent heat thermal energy storages (LHTES) are a promising technology witha wide range of applications in the framework of energy efficiency improve-ment. Phase change materials provide a big storage capacity, but their thermalconductivities are always extremely low. The use of finned tube heatexchangers is nowadays the best solution to enhance PCMs thermal perfor-mances. This allows significant charging and discharging rates. The majorchallenge concerns the balance between thermal performances and high mate-rial costs. A proper design of the heat transfer surfaces is essential to limit thesystem overall cost. Two different heat exchangers solutions, with radial andlongitudinal fins are here examined. The design of the LHTES is performed bydeploying a simplified FEM numerical model specifically developed for theapplication. A validation procedure based on laboratory tests with a smallLHTES prototype was also carried out. The obtained results confirmed the reli-ability of the numerical model and justify its adoption as a tool for the designphase. The FEM model allows to effectively simulate the system thermalbehaviour and assess the impact of the different HEX geometrical parameterson thermal performances. Based on this information it was possible to performthe optimization of the heat transfer surfaces and to derive the best heatexchanger layout in terms of material usage. The results showed that the solu-tion with longitudinal fins is the most efficient, with 215 kg of steel lessrequired for the realization of the finned heat exchanger

A one-stage approach to the treatment of intravenous leiomyomatosis extending to the right heart

This report describes the case of a 60-year-old woman with a history of hysterectomy for myomas, totally asymptomatic, with incidental evidence of a pelvic intracaval mass extending to the right atrium. She underwent a staged procedure (sternothomic and abdominal) through a thoracolaparotomic approach in circulatory arrest and deep hypothermia. Using a one-stage surgical approach, we were able to withdraw one portion of the mass from the right atrium and another from the abdominal inferior vena cava, thus minimizing the risk of unexpected venous or atrial wall injury during surgical manipulation

Serum Albumin Is Inversely Associated With Portal Vein Thrombosis in Cirrhosis

We analyzed whether serum albumin is independently associated with portal vein thrombosis (PVT) in liver cirrhosis (LC) and if a biologic plausibility exists. This study was divided into three parts. In part 1 (retrospective analysis), 753 consecutive patients with LC with ultrasound-detected PVT were retrospectively analyzed. In part 2, 112 patients with LC and 56 matched controls were entered in the cross-sectional study. In part 3, 5 patients with cirrhosis were entered in the in vivo study and 4 healthy subjects (HSs) were entered in the in vitro study to explore if albumin may affect platelet activation by modulating oxidative stress. In the 753 patients with LC, the prevalence of PVT was 16.7%; logistic analysis showed that only age (odds ratio [OR], 1.024; P = 0.012) and serum albumin (OR, -0.422; P = 0.0001) significantly predicted patients with PVT. Analyzing the 112 patients with LC and controls, soluble clusters of differentiation (CD)40-ligand (P = 0.0238), soluble Nox2-derived peptide (sNox2-dp; P < 0.0001), and urinary excretion of isoprostanes (P = 0.0078) were higher in patients with LC. In LC, albumin was correlated with sCD4OL (Spearman's rank correlation coefficient [r(s)], -0.33; P < 0.001), sNox2-dp (r(s), -0.57; P < 0.0001), and urinary excretion of isoprostanes (r(s), -0.48; P < 0.0001) levels. The in vivo study showed a progressive decrease in platelet aggregation, sNox2-dp, and urinary 8-iso prostaglandin F2 alpha-III formation 2 hours and 3 days after albumin infusion. Finally, platelet aggregation, sNox2-dp, and isoprostane formation significantly decreased in platelets from HSs incubated with scalar concentrations of albumin. Conclusion: Low serum albumin in LC is associated with PVT, suggesting that albumin could be a modulator of the hemostatic system through interference with mechanisms regulating platelet activation