Acceptable Limits for n-Hexane in Spacecraft Atmospheres

2021 ◽  
Vol 92 (12) ◽  
pp. 956-961
Author(s):  
Hector D. Garcia

INTRODUCTION:The Spacecraft Maximum Allowable Concentrations (SMACs) for C2-C9 alkanes set by NASA in 2008 under the guidance and approval of the National Research Council specifically excluded SMACs for n-hexane. Unlike other C2-C9 alkanes, n-hexane can cause polyneuropathy after metabolism in humans or rodents and so requires more stringent SMACs than the other members of this group do. This document reviews the relevant published studies of n-hexane toxicity to develop exposure duration-specific SMACs for n-hexane of 200 ppm for 1 hour, 30 ppm for 24 hours, and 2.4 ppm for 7 days, 30 days, 180 days, and 1000 days.Garcia HD. Acceptable limits for n-hexane in spacecraft atmospheres. Aerosp Med Hum Perform. 2021; 92(12):956–961.

2018 ◽  
Vol 10 (8) ◽  
pp. 1288 ◽  
Author(s):  
Filomena Romano ◽  
Domenico Cimini ◽  
Angela Cersosimo ◽  
Francesco Di Paola ◽  
Donatello Gallucci ◽  
...  

The Advanced Model for the Estimation of Surface Solar Irradiance (AMESIS) was developed at the Institute of Methodologies for Environmental Analysis of the National Research Council of Italy (IMAA-CNR) to derive surface solar irradiance from SEVIRI radiometer on board the MSG geostationary satellite. The operational version of AMESIS has been running continuously at IMAA-CNR over all of Italy since 2017 in support to the monitoring of photovoltaic plants. The AMESIS operative model provides two different estimations of the surface solar irradiance: one is obtained considering only the low-resolution channels (SSI_VIS), while the other also takes into account the high-resolution HRV channel (SSI_HRV). This paper shows the difference between these two products against simultaneous ground-based observations from a network of 63 pyranometers for different sky conditions (clear, overcast and partially cloudy). Comparable statistical scores have been obtained for both AMESIS products in clear and cloud situation. In terms of bias and correlation coefficient over partially cloudy sky, better performances are found for SSI_HRV (0.34 W/m2 and 0.995, respectively) than SSI_VIS (−33.69 W/m2 and 0.862) at the expense of the greater run-time necessary to process HRV data channel.


1973 ◽  
Vol 27 (4) ◽  
pp. 308-319 ◽  
Author(s):  
Z. Jaksic

Under the influence of ideas from control and communication theory, new trends have developed in the design of photogrammetric data-processing systems. In this paper a number of concepts applied to the design of such systems are discussed, with emphasis on the digital man-machine systems and system components. The main characteristics of contemporary photogrammetric systems are outlined in regard to both their hardware and software, including some remarks on automation and orthophototechniques. The general descriptions are supported by examples from two systems: one predominantly digital and the other predominantly analog. These examples concern the instrumental developments in the Photogrammetric Research Laboratories of the National Research Council of Canada.


1972 ◽  
Vol 1 (13) ◽  
pp. 1
Author(s):  
M.P. O'Brien

The Canadian Organizing Committee, the Vancouver Executive Committee and the National Research Council of Canada have done a superb job in planning this conference and in carrying out the enormous amount of detail necessary for its realization. On behalf of the Coastal Engineering Research Council, the other participating organizations, and all of the attendees I thank most heartily all who participated in this work. I am personally most grateful to those representatives of the Canadian Committee who made the final selection of papers. I should explain at this point that a small papers Committee is appointed for each of these conferences to review the summaries submitted by the authors - but this screening is intended only to appraise their appropriateness for a coastal engineering audience - and to eliminate those few papers which are promotional "blurbs". It has not been a technical review such as is made for "refereed" technical and scientific journals. The number of papers submitted for this Conference passing this simple review far exceeded the reasonable limits of the program - and for a brief period the Papers Committee faced the new and distasteful task of selection among papers acceptable under past standards. However, the problem was handled by the Canadian Committee - applying a formula which seemed equitable and reasonable. I trust that those affected concur in this judgment.


1972 ◽  
Vol 1 (13) ◽  
Author(s):  
Morrough P. O'Brien

The Canadian Organizing Committee, the Vancouver Executive Committee and the National Research Council of Canada have done a superb job in planning this conference and in carrying out the enormous amount of detail necessary for its realization. On behalf of the Coastal Engineering Research Council, the other participating organizations, and all of theattendees I thank most heartily all who participated in this work.


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