49 research outputs found
How Power-to-Gas strategy could reduce national Natural Gas consumption over the energy crisis period
Europe is facing an energy crisis caused by the dramatic rise in gas prices. This situation is damaging the European economy and urgent measures to reduce gas consumption are crucial in the short term. This paper aims to analyse the potential contribution of the Power-to-Gas strategy to reduce the Italian consumption of Natural Gas (NG) in the context of the current energy crisis. To do so, the Italian energy system has been modelled by means the EnergyPLAN software. The electrolysers' installation in the Italian energy systems has been simulated in combination with different levels of additional RES installation. The hydrogen production and the NG abatement potential have been calculated in each simulated scenario. Furthermore, the Natural Gas Abatement Cost (NGAC) has been assessed. By installing 1.5 GW of electrolysers, along with an additional 25 GW of renewables, about 140 ktonH2/year can be produced only by exploiting the RES excess. The total NG reduction due to both the RES generation and the hydrogen injection is more than 60 TWh/year. The NG abatement cost varies between 45 and 54 €/MWh. At current gas prices, it is therefore extremely cheaper to invest in a drastic reduction of natural gas than to buy the same amount of gas on the wholesale market. Therefore, the current energy crisis can be an opportunity to accelerate the energy transition process. The proposed solutions allow a substantial reduction in gas consumption with the consequent reduction in emissions and the country's energy dependency
Hybrid Hydrogen production: Application of CO2heat pump for the high-temperature water electrolysis process
Hydrogen is considered an energy vector which ensures a pivotal role in the energy market in near future. As a subsequent, the need to provoke novel technologies and investigate the potential layouts rising from hybridization remains on the shoulder of research literature., The current work investigates the potential role of the supercritical CO2 heat pump to contribute to hydrogen production inside a hybrid energy system. The case study is a generic biogas power plant characterized by the combination of diverse hydrogen production technologies such as water electrolysis and the reforming process. Water electrolysis takes place through high (SOEC) and low-temperature(AEC) The role of the heat pump unit is defined to operate between these two technologies to recover heat losses and transfer them to high-temperature electrolysis. The performance of the CO2 cycle in the presented hybrid energy system is simulated via MATLAB SIMULINK and the effective indicators to improve its performance have been carried out.In the end, the result of the simulation shows a production rate of 19.27 kgH2/h. Furthermore, thanks to heat recovery the total thermal efficiency increases by 80%. It also reveals that the heat pump unit operates with COP in the range of 4.5 – 3.3 based on pressure ratios providing temperature in the range of 151-184 °C by fixing the cold sink input temperature and pressure at 70 °C, 75 bar respectively
GI Bleeding in the Elderly
Purpose: To determine the risk factors contributing to and etiologies of gastrointestinal bleeding in an elderly patient population seen by Southwest Gastroenterology (SWGA) providers. Methods: This study reviews charts of patients with GI bleeding from documented sources between 1/1999 and 3/2006. The cases are gathered retrospectively from the clinical records of SWGA, a 12-person private, single specialty gastroenterology group serving community hospitals. Etiology and risk factors for GI hemorrhages are recorded in an elderly population, defined as patients age 55 and older. Results: GI hemorrhages are identified in 105 patients. The majority (83, 79%) of hemorrhages are upper GI bleeds (UGIB) comparing to 22 (21%) lower GI bleeds (LGIB). In the UGIB group, the most common etiology of bleed is gastric ulcer (29%). We also found 72% of UGIB patients on prescribed anticoagulation medications, including anti-platelet agents or non-steroidal anti-inflammatory drugs (NSAIDs). 20% of these patients are also positive for H. Pylori. Thirty patients in the UGIB group smoke or consume alcohol heavily (consuming more than 3 drinks per day for men and two drinks per day for women) while 2 patients smoke or consume alcohol in the LGIB group. Previous bleeds are common in both groups with 39 (41%) in UGIB and 9 (47%) in LGIB. Co-morbidity is the most common risk factor with 20 (91%) in LGIB and 73 (88%) in UGIB. In the peptic ulcer disease (PUD) bleeds, the majority (77%) are taking NSAIDs, while in the non-PUD bleeds, only 38% are currently on NSAIDs. Overall, there are 2 mortalities resulting from cardiovascular complications of GI bleeding. Conclusion: The etiologies of GI bleeds in this population are comparable to other studies in the literature. The ratio of UGIB to LGIB in this elderly population is also similar to that reported in the literature. The risk factors shown to be most correlated to bleeding are co-morbidities, previous episodes of bleeding, anticoagulation, NSAID use, smoking and alcohol use. NSAID use is significant in PUD bleed patients. This study reinforces that increased knowledge of etiology, incidence and contributing factors of GI bleeding are necessary for physicians to efficiently treat GI bleeds in the elderly population
Topical immunotherapy with diphencyprone in the treatment of extensive and/or long-lasting alopecia areata 11
Repeatability and reproducibility of deep-learning-based liver volume and Couinaud segment volume measurement tool
Purpose Volumetric and health assessment of the liver is crucial to avoid poor post-operative outcomes following liver resection surgery. No current methods allow for concurrent and accurate measurement of both Couinaud segmental volumes for future liver remnant estimation and liver health using non-invasive imaging. In this study, we demonstrate the accuracy and precision of segmental volume measurements using new medical software, Hepatica (TM).Methods MRI scans from 48 volunteers from three previous studies were used in this analysis. Measurements obtained from Hepatica (TM) were compared with OsiriX. Time required per case with each software was also compared. The performance of technicians and experienced radiologists as well as the repeatability and reproducibility were compared using Bland-Altman plots and limits of agreement.Results High levels of agreement and lower inter-operator variability for liver volume measurements were shown between Hepatica (TM) and existing methods for liver volumetry (mean Dice score 0.947 +/- 0.010). A high consistency between technicians and experienced radiologists using the device for volumetry was shown (+/- 3.5% of total liver volume) as well as low inter-observer and intra-observer variability. Tight limits of agreement were shown between repeated Couinaud segment volume (+ 3.4% of whole liver), segmental liver fibroinflammation and segmental liver fat measurements in the same participant on the same scanner and between different scanners. An underestimation of whole-liver volume was observed between three non-reference scanners.Conclusion Hepatica (TM) produces accurate and precise whole-liver and Couinaud segment volume and liver tissue characteristic measurements. Measurements are consistent between trained technicians and experienced radiologists.[GRAPHICS].Cardiovascular Aspects of Radiolog