On the Design of Heat Exchangers for Altitude Simulators

[EN] Altitude simulators for internal combustion engines are broadly used in order to simulate different atmospheric pressure and temperatures on a test bench. One of the main problems of these devices is their outlet temperature and in order to control it, at least one heat exchanger is needed. A methodology to define, select and analyses the best heat exchanger that fulfill the requirements is presented. The methodology combines CFD and 0D models with experimental test. The combination of these tools allows to adjust both the 0D and the CFD models. The adjusted 0D model will be used to perform parametric analysis that will help to select the best geometrical combinations considering heat transfer and pressure losses while the CFD model will help to find possible local deficiencies on the designed Heat Exchanger and, therefore, try to improve it. Finally, the adjusted 0D model have been used to perform parametric studies changing the most important geometric characteristics to analyze the effect on HEX performance.Broatch, A.; Olmeda, P.; Garcia Tiscar, J.; Roig-Villanueva, F. (2021). On the Design of Heat Exchangers for Altitude Simulators. SAE International. 1-12. https://doi.org/10.4271/2021-01-038811

Constructing ordinary places: Place-making in urban informal settlements in Mexico

Observers from a variety of disciplines agree that informal settlements account for the majority of housing in many cities of the global South. Urban informal settlements, usually defined by certain criteria such as self-build housing, sub-standard services, and residents’ low incomes, are often seen as problematic, due to associations with poverty, irregularity and marginalisation. In particular, despite years of research and policy, gaps in urban theory and limited understandings of urban informal settlements mean that they are often treated as outside ‘normal’ urban considerations, with material effects for residents including discrimination, eviction and displacement. In response to these considerations, this article uses a place-making approach to explore the spatial, social and cultural construction of place in this context, in order to unsettle some of the assumptions underlying discursive constructions of informal settlements, and how these relate to spatial and social marginalisation. Research was carried out using a qualitative, ethnographic methodology in two case study neighbourhoods in Xalapa, Mexico. Mexico offers fertile ground to explore these issues. Despite an extensive land tenure regularisation programme, at least 60 per cent of urban dwellers live in colonias populares, neighbourhoods with informal characteristics. The research found that local discourses reveal complex and ambivalent views of colonias populares, which both reproduce and undermine marginalising tendencies relating to ‘informality’. A focus on residents’ own place-making activities hints at prospects for rethinking urban informal settlements. By capturing the messy, dynamic and contextualised processes that construct urban informal settlements as places, the analytical lens of place-making offers a view of the multiple influences which frame them. Informed by perspectives from critical social geography which seek to capture the ‘ordinary’ nature of cities, this article suggests imagining urban informal settlements differently, in order to re-evaluate their potential contribution to the city as a whole

International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

International Nosocomial Infection Control Consortiu (INICC) report, data summary of 43 countries for 2007-2012. Device-associated module

We report the results of an International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2007-December 2012 in 503 intensive care units (ICUs) in Latin America, Asia, Africa, and Europe. During the 6-year study using the Centers for Disease Control and Prevention's (CDC) U.S. National Healthcare Safety Network (NHSN) definitions for device-associated health care–associated infection (DA-HAI), we collected prospective data from 605,310 patients hospitalized in the INICC's ICUs for an aggregate of 3,338,396 days. Although device utilization in the INICC's ICUs was similar to that reported from ICUs in the U.S. in the CDC's NHSN, rates of device-associated nosocomial infection were higher in the ICUs of the INICC hospitals: the pooled rate of central line–associated bloodstream infection in the INICC's ICUs, 4.9 per 1,000 central line days, is nearly 5-fold higher than the 0.9 per 1,000 central line days reported from comparable U.S. ICUs. The overall rate of ventilator-associated pneumonia was also higher (16.8 vs 1.1 per 1,000 ventilator days) as was the rate of catheter-associated urinary tract infection (5.5 vs 1.3 per 1,000 catheter days). Frequencies of resistance of Pseudomonas isolates to amikacin (42.8% vs 10%) and imipenem (42.4% vs 26.1%) and Klebsiella pneumoniae isolates to ceftazidime (71.2% vs 28.8%) and imipenem (19.6% vs 12.8%) were also higher in the INICC's ICUs compared with the ICUs of the CDC's NHSN