Characterization of Swept Synthetic High Quality Quartz Crystal

2014 ◽  
Vol 633 ◽  
pp. 326-329
Author(s):  
Shao Feng Zhang ◽  
Ji Wu Shang
Keyword(s):  
Radiation Effects ◽  
Quartz Crystal ◽  
Ionic Conduction ◽  
Promising Result ◽  
Temperature Stability ◽  
Radiation Environment ◽  
Thermal Coefficient ◽  
Space Applications ◽  
Wide Range ◽  
Voltage Current Characteristic

The synthetic quartz crystal is widely utilized in electronic and optical components due to its high frequency and temperature stability, good dielectric properties, low thermal coefficient of linear expansion, and wide range of optical transparency. However, radiation effects due to cosmic rays are responsible for a frequency shift for quartz oscillators in space systems, which impair their performance. Sweeping quartz at high electric field is a well-established method for improving device performance in a radiation environment. The present paper focuses on the voltage current characteristic of swept quartz. First, the sweeping conduction mechanism is ionic conduction. Second, as the voltage increases, the current increases first, then decreases, and then increases. ICP-AES results indicated that the sweeping process make Na+ a oriented locomotion. Third, the etch channel tensity is obviously reduced to less than 3/cm3, which is a very promising result for space applications. Moreover, the radiation resistance properties are improved after electrical sweeping.

scholarly journals Chlorella Vulgaris Photobioreactor for Oxygen and Food Production on a Moon Base—Potential and Challenges

2021 ◽  
Vol 8 ◽  
Author(s):  
Gisela Detrell
Keyword(s):  
Chlorella Vulgaris ◽  
Radiation Effects ◽  
Life Support ◽  
Higher Plants ◽  
Algal Species ◽  
Processing System ◽  
Space Applications ◽  
Operational Conditions ◽  
Wide Range

A base on the Moon surface or a mission to Mars are potential destinations for human spaceflight, according to current space agencies’ plans. These scenarios pose several new challenges, since the environmental and operational conditions of the mission will strongly differ than those on the International Space Station (ISS). One critical parameter will be the increased mission duration and further distance from Earth, requiring a Life Support System (LSS) as independent as possible from Earth’s resources. Current LSS physico-chemical technologies at the ISS can recycle 90% of water and regain 42% of O2 from the astronaut’s exhaled CO2, but they are not able to produce food, which can currently only be achieved using biology. A future LSS will most likely include some of these technologies currently in use, but will also need to include biological components. A potential biological candidate are microalgae, which compared to higher plants, offer a higher harvest index, higher biomass productivity and require less water. Several algal species have already been investigated for space applications in the last decades, being Chlorella vulgaris a promising and widely researched species. C. vulgaris is a spherical single cell organism, with a mean diameter of 6 µm. It can grow in a wide range of pH and temperature levels and CO2 concentrations and it shows a high resistance to cross contamination and to mechanical shear stress, making it an ideal organism for long-term LSS. In order to continuously and efficiently produce the oxygen and food required for the LSS, the microalgae need to grow in a well-controlled and stable environment. Therefore, besides the biological aspects, the design of the cultivation system, the Photobioreactor (PBR), is also crucial. Even if research both on C. vulgaris and in general about PBRs has been carried out for decades, several challenges both in the biological and technological aspects need to be solved, before a PBR can be used as part of the LSS in a Moon base. Those include: radiation effects on algae, operation under partial gravity, selection of the required hardware for cultivation and food processing, system automation and long-term performance and stability.

A virtual test environment for validating spacecraft optical navigation

2013 ◽  
Vol 117 (1197) ◽  
pp. 1075-1101 ◽  
Author(s):  
S. M. Parkes ◽  
I. Martin ◽  
M. N. Dunstan ◽  
N. Rowell ◽  
O. Dubois-Matra ◽  
...  
Keyword(s):  
Small Body ◽  
European Space Agency ◽  
Ground Truth ◽  
Camera Motion ◽  
Test Environment ◽  
Space Applications ◽  
Vision Guidance ◽  
Space Agency ◽  
Wide Range ◽  
And Performance

Abstract The use of machine vision to guide robotic spacecraft is being considered for a wide range of missions, such as planetary approach and landing, asteroid and small body sampling operations and in-orbit rendezvous and docking. Numerical simulation plays an essential role in the development and testing of such systems, which in the context of vision-guidance means that realistic sequences of navigation images are required, together with knowledge of the ground-truth camera motion. Computer generated imagery (CGI) offers a variety of benefits over real images, such as availability, cost, flexibility and knowledge of the ground truth camera motion to high precision. However, standard CGI methods developed for terrestrial applications lack the realism, fidelity and performance required for engineering simulations. In this paper, we present the results of our ongoing work to develop a suitable CGI-based test environment for spacecraft vision guidance systems. We focus on the various issues involved with image simulation, including the selection of standard CGI techniques and the adaptations required for use in space applications. We also describe our approach to integration with high-fidelity end-to-end mission simulators, and summarise a variety of European Space Agency research and development projects that used our test environment.

Developing low-cost methane gas concentration measuring device

2021 ◽  
pp. 54-59
Author(s):  
Md. Mahidy Hossain ◽  
Nadim Khandaker
Keyword(s):  
Promising Result ◽  
Low Cost ◽  
Measurement Techniques ◽  
Health And Safety ◽  
Modern Science ◽  
Methane Content ◽  
Measuring Device ◽  
Methane Generation ◽  
Methane Gas ◽  
Wide Range

In every aspect of Engineering more advanced, efficient and progressive solutions are required. The modern age of science requires innovative minds. The field of environmental engineering is also advancing with modern science and technology innovations. Measuring of methane concentration and flow rate is nothing new, yet a complicated process. The need for more accurate measurement is a necessity in proper operation of bio digesters for methane generation. The traditional process of the measuring methane content in biogas is time consuming yet complicated. The need for development and application of methane measurement techniques is not only limited to biogas but has other monitoring value as well in other health and safety applications in built environments. Winsen Electronics and Hanwei Electronics are two of the leading sensor-manufactures of China who are providing a wide range of gas detecting sensors that are locally available in Bangladesh and yet has not been applied to methane content measurement in biogas operations. In This paper we are reporting on the application of a purpose-built propane, butane detector for methane gas detection within the range of accuracy for it to be applied in methane detection in a biogas stream. This paper, reports on application and calibration of the methane detecting sensor MQ-4 with promising result. Based on the study we postulate that the sensor can be used to detect methane for an on-line monitoring of many environmental, industrial purposes such as bio digesters, integrated waste management facility. The cost of fabrication of the sensor system is only $18 making it a viable sensor with respect to cost for application in Bangladesh.

Wide range temperature stability of palladium on ceria-praseodymia catalysts for complete methane oxidation

2021 ◽  
Author(s):  
Sabrina Ballauri ◽  
Enrico Sartoretti ◽  
Chiara Novara ◽  
Fabrizio Giorgis ◽  
Marco Piumetti ◽  
...  
Keyword(s):  
Methane Oxidation ◽  
Temperature Stability ◽  
Wide Range

scholarly journals Total Ionizing Dose Effects on a Delay-Based Physical Unclonable Function Implemented in FPGAs

Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 163 ◽  
Author(s):  
Honorio Martin ◽  
Pedro Martin-Holgado ◽  
Yolanda Morilla ◽  
Luis Entrena ◽  
Enrique San-Millan
Keyword(s):  
Low Cost ◽  
Ring Oscillator ◽  
Radiation Environment ◽  
Key Generation ◽  
Total Ionizing Dose ◽  
Space Applications ◽  
Physical Unclonable Functions ◽  
Dose Effects ◽  
Total Ionizing Dose Effects

Physical Unclonable Functions (PUFs) are hardware security primitives that are increasingly being used for authentication and key generation in ICs and FPGAs. For space systems, they are a promising approach to meet the needs for secure communications at low cost. To this purpose, it is essential to determine if they are reliable in the space radiation environment. In this work we evaluate the Total Ionizing Dose effects on a delay-based PUF implemented in SRAM-FPGA, namely a Ring Oscillator PUF. Several major quality metrics have been used to analyze the evolution of the PUF response with the total ionizing dose. Experimental results demonstrate that total ionizing dose has a perceptible effect on the quality of the PUF response, but it could still be used for space applications by making some appropriate corrections.

Tailored Solutions for Off-Shore Applications by Plazjet Sprayed Coatings

1997 ◽  
Author(s):  
F. Ladru ◽  
E. Lugscheider ◽  
H. Jungklaus ◽  
C. Herbst ◽  
I. Kvernes
Keyword(s):  
Process Control ◽  
Thermal Spraying ◽  
Temperature Stability ◽  
Hard Coatings ◽  
High Temperature Stability ◽  
Coating Quality ◽  
Large Structures ◽  
Wide Range ◽  
Sprayed Coatings ◽  
Suitable Process

Abstract For very large structures and parts in critical environments, a materials solution often cannot be found by using one material. The specific desired properties for those structures, like stiffness, ductility, high temperature stability, corrosion resistance, etc. are difficult to fulfill with only one material. In this case a solution may be found by using coatings and design their specific properties to replenish each other by their combination. The Thermal Spraying processes offer the necessary flexibility of producing thin to thick, ductile, soft to hard coatings while due to the wide range of process temperatures it is possible to process a wide range of materials, both as coating and structure. In this paper the some recent and important developments in Thermal Spraying to produce coatings for technical demanding structures will be described. These developments consist of High Power Plasma Spraying, powder- and process control development. To ensure process consistency during long spraying times and to apply reproducible coating quality a suitable process control is of great importance and the development of temperature control by Pyrometry and Thermography will be presented. The example will be drawn according to the application of a coating on a ball valve for off-shore and ship diesel engine parts (piston and valve).

High-Temperature Spin-On Adhesives for Temporary Wafer Bonding

2007 ◽  
Vol 4 (3) ◽  
pp. 105-111 ◽  
Author(s):  
S. Pillalamarri ◽  
R. Puligadda ◽  
C. Brubaker ◽  
M. Wimplinger ◽  
S. Pargfrieder
Keyword(s):  
High Temperature ◽  
Wafer Bonding ◽  
Heat Dissipation ◽  
Temperature Stability ◽  
High Temperature Stability ◽  
Performance Requirements ◽  
Wide Range ◽  
Bonding Properties ◽  
Partial List ◽  
Wafer Thinning

Wafer thinning has been effectively used to improve heat dissipation in power devices and to fabricate flexible substrates, small chip packages, and multiple chips in a package. Wafer handling has become an important issue due to the tendency of thinned wafers to warp and fold. Thinned wafers need to be supported during the backgrinding process, lithography, deposition, etc. Temporary wafer bonding using removable adhesives provides a feasible route to wafer thinning. Existing adhesives meet only a partial list of performance requirements. They do not meet the requirements of high-temperature stability combined with ease of removal. This paper reports on the development of a wide range of temporary adhesives to be used in wafer thinning applications that use both novel and conventional bonding and debonding methods. We have developed a series of novel removable high-temperature spin-on adhesives with excellent bonding properties and a wide range of operating temperatures for bonding and/or debonding to achieve a better processing window.

Contrasting Responses of Morphologically Similar Wheat Cultivars to Temperatures Appropriate to Warm Temperature Climates With Hot Summers: a Study in Controlled Environment

1977 ◽  
Vol 4 (6) ◽  
pp. 877 ◽  
Author(s):  
AK Bagga ◽  
HM Rawson
Keyword(s):  
Temperature Stability ◽  
Kernel Weight ◽  
Controlled Environment ◽  
Wheat Cultivars ◽  
Warm Temperature ◽  
Temperature Regimes ◽  
Wide Range ◽  
Phase Temperature ◽  
Warm Temperate ◽  
Plant Basis

This study attempted to determine if and why there are differences among three cultivars of wheat in their responses to temperature. The three semidwarf cultivars examined, Kalyansona, Condor and Janak, are currently used commercially. Temperature regimes chosen matched the range to which plants in warm temperate climates with hot summers would be exposed at different stages of development. Plants were grown in a phytotron in sunlit cabinets. Responses to temperature were different among the cultivars. Kalyansona was relatively un- responsive to temperatures during the floret phase, being little affected in the sizes of upper leaves, in floret production and grain set, in overall plant growth or in grain yield. The sole character to respond to temperature in this cultivar was kernel weight, which declined with increasing grain phase temperature. In contrast, Condor demonstrated marked plasticity during the floret phase in all plant characters measured. Its plasticity was such that, at the lower temperatures, it outyielded Kalyansona by a substantial margin while at the higher temperatures its yield was relatively poor. On a plant basis, Janak performed similarly to Condor. Rates of photosynthesis were relatively unaffected by temperature in any cultivar. This wide range of response among three superficially similar cultivars has promising implications for the tailoring of cultivars for different temperature zones. The importance of different plant characters to temperature stability is considered in the discussion.

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