Engineering topics

Dunlop, E. H.

Publications and source records attributed to Dunlop, E. H..

4 records

NASA NTRS1992

Life sciences and space research XXIV(4) - Natural and artificial ecosystems; Proceedings of the Topical Meeting of the Interdisciplinary Scientific Commission F (Meetings F10, F11, F1 and F12) of the COSPAR 28th Plenary Meeting, The Hague, Netherlands, June 25-July 6, 1990

The present conference on natural and artificial ecosystems and their application to space research encompasses both in-flight and ground-based issues of recycling and control in regenerative life support, the relationships of productivity and facility design in higher plant growth, life-support systems for manned missions to Mars, and biochemical engineering applications in space. Specific issues addressed include interface problems between material recycling systems and plants, temperature and humidity control on a lunar base, the CELSS Test-Facility Project, achieving closure in plant-growth facilities, and life-support systems for Mars transit. Also addressed are a closed equilibrated biological aquatic system, a simulated Mars outpost in the Antarctica dry valleys, analyses of human kidney-cell populations separated on the space shuttle, and the evolution of a phase-separated gravity-independent bioreactor.

Macelroy, R. D.↗

NASA NTRS1989

Phase separated membrane bioreactor - Results from model system studies

The operation and evaluation of a bioreactor designed for high intensity oxygen transfer in a microgravity environment is described. The reactor itself consists of a zero headspace liquid phase separated from the air supply by a long length of silicone rubber tubing through which the oxygen diffuses in and the carbon dioxide diffuses out. Mass transfer studies show that the oxygen is film diffusion controlled both externally and internally to the tubing and not by diffusion across the tube walls. Methods of upgrading the design to eliminate these resistances are proposed. Cell growth was obtained in the fermenter using Saccharomyces cerevisiae showing that this concept is capable of sustaining cell growth in the terrestrial simulation.

Petersen, G. R.↗

NASA NTRS1987

Design concepts for bioreactors in space

Microbial food sources are becoming viable and more efficient alternatives to conventional food sources, especially in the context of closed ecological life support systems (CELSS) in space habitats. Two bioreactor design concepts presented represent two dissimilar approaches to grappling with the absence of gravity in space habitats and deserve to be tested for adoption as important components of the life support function aboard spacecraft, space stations and other extra-terrestrial habitats.

Seshan, P. K.↗

NASA NTRS1986

Design concepts for bioreactors in space

Microbial food sources are becoming viable and more efficient alternatives to conventional food sources especially in the context of Closed Ecological Life Support Systems (CELSS) in space habitats. Since bioreactor designs for terrestrial operation will not readily apply to conditions of microgravity, there is an urgent need to learn about the differences. These differences cannot be easily estimated due to the complex nature of the mass transport and mixing mechanisms in fermenters. Therefore, a systematic and expeditious experimental program must be undertaken to obtain the engineering data necessary to lay down the foundations of designing bioreactors for microgravity. Two bioreactor design concepts presented represent two dissimilar approaches to grappling with the absence of gravity in space habitats and deserve to be tested for adoption as important components of the life support function aboard spacecrafts, space stations and other extra-terrestrial habitats.

Seshan, P. K.↗