Investigation of Tank Pressurization and Pressure Control—Part I: Experimental Study

Author(s):  
Stephen Barsi ◽  
Mohammad Kassemi

Self-pressurization and pressure control of cryogenic storage tanks have important design consequences for propellant and life support systems currently being planned for long duration space missions. During self-pressurization, the tank's liquid fill level and the heat load from the surroundings can have significant effects on the tank's thermal stratification and pressurization rate. When controlling pressure with a mixing jet, the velocity and temperature of the jet are important design parameters affecting the thermal destratification and pressure reduction time constants. In this work, a small-scale ground-based experiment was performed, as a precursor to a microgravity experiment, to investigate the effects of these variables on the pressurization and pressure control time constants in the tank and to assess the feasibility of using a forced jet mixer for reduced boil-off pressure control. Local pointwise temperature and pressure measurements, together with qualitative contours of the thermal field in the liquid, vapor, and wall region, were made to identify and characterize important self-pressurization and pressure control trends in 1 g.

Author(s):  
Mark Baldry ◽  
Nicholas Gurieff ◽  
Declan Keogh

Extensive in-situ resource utilisation (ISRU) will be essential to enable long-duration stays on Luna and Mars and reduce reliance on resupply from Earth. Early development of ISRU technologies has focused on standalone capabilities for specific targets related to life support and ascent propellant. An unexplored opportunity remains for greatly expanding the scope of materials that can be supplied by ISRU, and for integrating various technology platforms into a larger system. Recent advances in power-to-X technology aimed at decarbonising the global economy have made it possible to drive key chemical processes using electricity with small-scale, modular reactor. This paper proposes a vision for an integrated system of ISRU processes based on power-to-X technology to produce oxygen, hydrogen, water, methane, polymers, metal alloys, and synthetic fertilisers, using Martian regolith, atmosphere, and ice. A ‘building block’ strategy is adopted to convert raw materials into versatile intermediaries, which can then be combined to form essential products. A wider range of raw materials are available on Mars compared to Luna, suggesting greater opportunity for ISRU deployment to compensate for the greater time and cost requirements for a Mars resupply mission.


Author(s):  
Boris F. ZARETSKIY ◽  
Arkadiy S. GUZENBERG ◽  
Igor A. SHANGIN

Life support for first manned spaceflights was based on supplies of consumables. Crew life support systems based on supplies of water and oxygen, in spite of their simplicity, are extremely inefficient in orbital space missions and are unfeasible in deep space missions because of mass and volume constraints. Therefore, there are currently developed and are to be used on space stations the life support systems that are based on chemical and physical regeneration of water and oxygen extracted from human waste. In view of further advances in long-duration orbital stations, and the prospects of establishment of planetary outposts and deep space exploration, the problem of constructing an automated system for controlling a suite of regenerative LSS becomes urgent. The complexity of solving the problem of constructing an efficient control system in this case owes to the existence of a large number of effectiveness criteria. The paper proposes a system of consolidated global efficiency criteria, which allows to break up this problem into a series of sub-problems of optimization in order to solve this problem. The proposed criteria are longevity, cost, comfort. The paper presents a series of specific examples of using the proposed principles with necessary generalizations. Key words: space life support systems, atmosphere revitalization equipment, automated control system, global generalized efficiency criteria, longevity, cost, comfort.


2014 ◽  
Vol 955-959 ◽  
pp. 3393-3399 ◽  
Author(s):  
Wei Zheng ◽  
Yan Ming Yang ◽  
Yun Long Li ◽  
Jian Qiu Zheng

The process technique and design parameters of project of Solar Ozonic Ecological Sewage Treatment Plant (short for SOESTP) which consists of anaerobic reactor, horizontal subsurface flow (HSSF) constructed wetlands(CWs) and the combination of solar power and ozone disinfection are described, the paper further examines the removal efficiency for treating rural domestic sewage, running expense and recycling ability of product water. The results show that the average percentage removal values of CODcr,BOD5,SS,TN,NH3-N,TP range from 95.6% to 98.0%, 96.0% to 98.7%, 93.1% to 96.1%, 97.0% to 98.9%, 96.9% to 99.5%, 98.2% to 99.6%, respectively, the reduction of fecal coliform (FC) reaches 99.9%, the effluent quality meets the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant(GB18918-2002). The running cost of SOESTP is 0.063yuan/ m3, saves much more than traditional sewage treatment, and the ozone water obtained from the reservoir will be an ideal choice for disinfection .The system has characteristics of easy manipulation, low operating cost, achieving advanced water, energy conservation and environment protection, is thought to be very suitable for use as the promotion of rural small - scale sewage treatment.


1981 ◽  
Vol 59 (12) ◽  
pp. 2558-2567 ◽  
Author(s):  
K. E. Percy ◽  
R. T. Riding

Two-year-old seedlings of Pinus strobus were grown from budbreak to bud set (11 weeks) in air containing 132 ± 26 μg SO2∙m−3. Histological and histochemical effects on elongating needles were examined. Cellular injury was restricted to mesophyll parenchyma. Affected cells manifested a progressive alteration of protoplast staining proportional to the degree of injury. Total carbohydrates and plastids aggregated at cell walls. Total proteins and proteins containing sulfhydryl–disulfide groups decreased. Phospholipid staining in the plasmalemma – cell wall region appeared reduced. Succinic dehydrogenase activity was enhanced and was apparent longer in injured cells. Needle ontogeny was slowed in fumigated seedlings. There were no significant differences in external growth parameters after 11 weeks. The injury can, therefore, be classified as latent or hidden. The SO2 effects could contribute to a growth reduction in successive increments.


2018 ◽  
Vol 13 (3) ◽  
pp. 72-76
Author(s):  
Гумар Булгариев ◽  
Gumar Bulgariev ◽  
Геннадий Пикмуллин ◽  
Gennadiy Pikmullin ◽  
Ильгиз Галиев ◽  
...  

At the present stage of development of the country’s agro-industrial complex, the technological process of surface tillage by combined soil-cultivating machines, simultaneously combining a number of operations in one pass through the field, causes the presence in their designs of the necessary set of various promising working organs. In view of the foregoing, a rotary soil ripper with a spiral-plate working member equipped with radially directed teeth and connected by means of rods with end flanges has been developed. Also, the researched ripper has the limits of penetration of the working element in the form of flat discs equipped with flanges and the radial stop have the ability to rotate around their axes independently of the ripper shaft. An analytical study of the working units of this ripper was carried out from the point of view of the influence of their size and teeth on the process of interaction with the soil, on the basis of which some of their parameters were determined. In conclusion, it was concluded that the analytical equations obtained allow us to justify the choice of the most important design parameters of the proposed new design and design a toothed rotary working device that reduces to constructive implementation after calculating their basic dimensions.


Author(s):  
Riley Orabona Wagner ◽  
Sydney Hsu ◽  
John Nicholas Kick ◽  
Sofia Bisogno ◽  
Camille Heubner ◽  
...  

This paper analyzes the methods utilized by the Princeton University Chapter of Engineers Without Borders to ensure the sustainability of a gravity-fed water system in rural northwestern Peru. While similar small scale development projects consider sustainability in their design process, some do not recognize the importance of an interdisciplinary approach to sustainability. This team, however, is inherently interdisciplinary in nature due to its unique subteam structure, which subsequently affects its approach to sustainability. By examining the technical, social, and financial considerations of the project conducted by the Princeton University Chapter of Engineers Without Borders, this paper argues for a three-pronged approach to sustainability. As can be seen through thoughtful design parameters, strong local partnerships, and strategic financial mechanisms, the project displays promise of future success with regards to sustainability. The main objective of the Princeton Chapter of Engineers Without Borders in this partnership is to ensure that the community has the knowledge, tools, and resources necessary to maintain the water system in a self-sufficient manner at the completion of the chapter’s involvement.


2019 ◽  
Vol 14 (10) ◽  
pp. 87 ◽  
Author(s):  
Arshia Taimouri ◽  
Korosh Emamisaleh ◽  
Davoud Mohammadi

Following the rapid development of the Internet, e-commerce websites are widely used today for various goals. An essential point in the prosperity of these websites is their level of usability. Accordingly, measuring this usability is indispensable for these websites to check whether they are moving in the right path. Thus, in this article, the usability scores of five well-known online food-ordering websites in Iran have been evaluated using a novel fuzzy Kano method with respect to design parameters. In addition to assessing usability scores, the design parameters of these websites have been classified and reviewed in a detailed manner in order to determine the design priorities of these websites as one of the main results of this study. Data were gathered using a questionnaire with 190 respondents. Results demonstrated that Snappfood is the best online food-ordering website in Iran. In addition, sorting restaurants based on customer satisfaction score, using high-quality images of foods along with the image zooming feature, and the existence of complete information about foods and restaurants are the most effective and important design parameters of these types of websites according to the findings of this study.


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