Numerical study of the air distribution in the Crew Quarters on board of the International Space Station

The current concept of Crew Quarters on board of the International Space Station has several issues according to the crew member’s feedback. Major issues concern noise levels, the accumulation of CO2 and the quality of the air distribution. Our study targets the airflow distribution, to diagnose this issue, we realise a series of numerical simulations (CFD) based on a real scale replica of the Crew Quarters. Simulations were set with a zero-gravity mode and with the theoretical air parameters inside the SSI. The geometry includes a thermal manikin having the neutral posture of a body in the absence of gravity. Numerical simulations were run for the three different air flow rates provided by the current ventilation system. Results have shown that the air distribution inside the Crew Quarter is insufficient for low airflow rates but becomes acceptable for the higher airflow rate, however the higher airflow rate can potentially produce draught discomfort

Numerical study of the air distribution in the Crew Quarters on board of the International Space Station

International audienc

An alternative air distribution solution for better environmental quality in the ISS crew quarters

International audienceThis article presents the study of a ventilation solution using cross-flow fans for the crew quarters (CQ) aboard the International Space Station. Currently the CQ uses two axial fans for ventilation, which occasionally generate insufficient flow rate or acoustic issues. A ventilation circuit using two cross-flow fans was designed, its acoustic performance was measured and the flow was investigated via CFD by using the measured cross-flow fan operating curves as boundary conditions. The acoustic performance of the fans was evaluated in isothermal conditions, under the assumption that the heat generated by the occupants and equipment would produce negligible thermal buoyancy effects in microgravity on the station. Future studies will investigate how the internal heat generated in the enclosure affects the thermal comfort conditions of the occupants. After a comparison between the axial and cross-flow fan systems, results indicate that the latter provides better acoustic parameters for the same flow rate with less energy consumption

Experimental Study of Carbon Dioxide Accumulation on a Model of the Crew Quarters on the ISS

International audienc

Numerical Prediction of Carbon Dioxide Accumulation in the International Space Station Crew Quarters

International audienc

Design of a Small-Scale Experimental Model of the International Space Station Crew Quarters for a PIV Flow Field Study

International audienc

Personalized Ventilation as a Possible Strategy for Reducing Airborne Infectious Disease Transmission on Commercial Aircraft

In the last decade, there has been an increase in ease and affordability of air travel in terms of mobility for people all around the world. Airplane passengers may experience different risks of contracting airborne infectious diseases onboard aircraft, such as influenza or severe acute respiratory syndrome (SARS-CoV-1 and SARS-CoV-2), due to nonuniform airflow patterns inside the airplane cabin or proximity to an infected person. In this paper, a novel approach for reducing the risk of contracting airborne infectious diseases is presented that uses a low-momentum personalized ventilation system with a protective role against airborne pathogens. Numerical simulations, supported by nonintrusive experimental measurements for validation purposes, were used to demonstrate the effectiveness of the proposed system. Simulation and experimental results of the low-momentum personalized ventilation system showed the formation of a microclimate around each passenger with cleaner and fresher air than produced by the general mixing ventilation systems

Posttranslational Modifications Pattern in Clear Cell Renal Cell Carcinoma

Posttranslational modifications are dynamic enzymatic-mediated processes, regulated in time and space, associated with cancer development. We aimed to evaluate the significance of posttranslational modifications in the pathogenesis of clear cell renal cell carcinoma. The authors developed a prospective, observational study during a period of three years and included 55 patients with localized renal cell carcinoma and 30 heathy subjects. Glycosylation, nitration and carbonylation, thiol-disulfide homeostasis, methylation, phosphorylation and proteolytic cleavage were evaluated in the serum of the evaluated subjects in the present study. Our results showed some characteristics for early ccRCC: high production of cytokines, substrate hypersialylation, induced nitrosative and carbonylic stress, arginine hypermethylation, thiol/disulfide homeostasis (TDH) alteration, the regulatory role of soluble receptors (sRAGE—soluble receptor for advanced glycation end products, sIL-6R—soluble receptor for Interleukin 6) in RAGE and IL-6 signaling, the modulatory effect of TK1—thymidine kinase 1 and TuM2-PK—tumoral pyruvate-kinase 2 in controlling the level of phosphometabolites in neoplastic cells. These data could be the initial point for development of a panel of biomarkers such as total sialic acid, orosomucoids, nitrotyrosine, carbonylic metabolites, Asymmetric Dimethylarginines (ADMA), Symmetric Dimethylarginines (SDMA), and thiol-disulfide equilibrium for early diagnosis of ccRCC. Moreover, they could be considered a specific disease posttranslational modification signature which underlines the transition from early to advanced stages in this neoplasia, and of a therapeutic target in kidney oncogenesis

Study on Energy Efficiency of an Off-Grid Vending Machine with Compact Heat Exchangers and Low GWP Refrigerant Powered by Solar Energy

The purpose of this research is to design an energy-efficient off-grid vending machine that has a refrigeration system powered by an environmentally friendly refrigerant. The paper presents details from the equipment’s design phase in terms of the resistance structure, photovoltaic panels area dimensioning, but also in terms of the necessary cooling load to be provided by the refrigeration system. The refrigerant chosen was R290 following a comparative analysis, which showed that it has an efficiency 6.6% higher than R134a. During the monitoring periods, the outdoors temperature varied between −4–28 °C, the relative humidity between 22–100% and yet only a slight indoor temperature variation of ±1.5 °C compared to the set value was recorded. The battery module managed to store enough energy from the photovoltaic panels to keep the vending machine functional through three consecutive days with adverse environmental conditions, as evidenced by the low variation of indoor temperatur