scholarly journals Experimental Characterization of Weightlessness During Glider Parabolic Flights

2020 ◽  
Vol 32 (6) ◽  
pp. 1121-1132
Author(s):  
Denis-Gabriel Caprace ◽  
Camille Gontier ◽  
Mohammad Iranmanesh ◽  
Mehdi Scoubeau ◽  
Vladimir Pletser
Keyword(s):  
Applied Sciences ◽  
Lower Cost ◽  
Flight Test ◽  
Microgravity Environment ◽  
Lead Times ◽  
Space Systems ◽  
Sounding Rockets ◽  
Parabolic Flights ◽  
Start Up

Abstract Access to earthbound weightlessness is critical to many branches of applied sciences. Besides, several space systems require microgravity testing before their launch. Existing solutions (drop towers, parabolic flights, sounding rockets) offer variable durations and qualities of microgravity environment, but their cost and lead times make them unpractical for small actors such as universities or start-up companies. This leads to a growing interest for alternative microgravity platforms. Here, we study the use of gliders to perform parabolic flights at a lower cost, and we propose a systematic quantification of glider’s 0-g flight capabilities. Results of our flight test campaign show that gliders offer up to 5.5s of weightlessness, with excursions below 0.1g, and a satisfactory level of repeatability. Besides, the recordings do not suffer from the increased level of vibrations generated by piston engines, typical of light-aircraft-based alternatives. Operational considerations associated with glider parabolic flights are also discussed. Finally, we conclude that a microgravity platform based on gliders would be suitable especially for compact experiments and equipment in order to support accelerated design and development, or to produce preliminary experimental results.

scholarly journals Impact of generator start-up lead times on short-term scheduling with high shares of renewables

2020 ◽  
Vol 268 ◽  
pp. 114935
Author(s):  
Mathias Hermans ◽  
Kenneth Bruninx ◽  
Erik Delarue
Keyword(s):  
Lead Times ◽  
Short Term ◽  
Start Up

Characteristics in Response Integration and Bifurcation of a Forced Duffing Oscillator

2007 ◽  
Author(s):  
Jang-Der Jeng ◽  
Yuan Kang ◽  
Yeon-Pun Chang ◽  
Shyh-Shyong Shyr
Keyword(s):  
Applied Sciences ◽  
Phase Plane ◽  
Duffing Oscillator ◽  
High Order ◽  
Chaotic Motions ◽  
Integration Algorithm ◽  
High Order Harmonic ◽  
Stiffness And Damping

The Duffing oscillator is well-known models of nonlinear system, with applications in many fields of applied sciences and engineering. In this paper, a response integration algorithm is proposed to analyze high-order harmonic and chaotic motions in this oscillator for modeling rotor excitations. This method numerically integrates the distance between state trajectory and the origin in the phase plane during a specific period and predicted intervals with excitation periods. It provides a quantitative characterization of system responses and can replace the role of the traditional stroboscopic technique (Poincare´ section method) to observe bifurcations and chaos of the nonlinear oscillators. Due to the signal response contamination of system, thus it is difficult to identify the high-order responses of the subharmonic motion because of the sampling points on Poincare´ map too near each other. Even the system responses will be made misjudgments. Combining the capability of precisely identifying period and constructing bifurcation diagrams, the advantages of the proposed response integration method are shown by case studies. Applying this method, the effects of the change in the stiffness and the damping coefficients on the vibration features of a Duffing oscillator are investigated in this paper. From simulation results, it is concluded that the stiffness and damping of the system can effectively suppress chaotic vibration and reduce vibration amplitude.

A New In-line Laser-based Acoustic Technique for Pillar Bump Metrology

2015 ◽  
Vol 2015 (1) ◽  
pp. 000486-000492
Author(s):  
Todd W. Murray ◽  
Andrew Bakir ◽  
David M. Stobbe ◽  
Michael J. Kotelyanskii ◽  
Robin A. Mair ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Lower Cost ◽  
Ion Beam ◽  
High Sensitivity ◽  
Reduced Form ◽  
Vibrational Modes ◽  
Acoustic Technique ◽  
Key Drivers ◽  
Improved Performance

The drive to reduce the interconnect pitch and increase the number of connections for packaging in mobile devices has led to the development of copper pillar bumps. The key drivers for the adoption of copper pillars are improved performance, reduced form factor and lower cost. In this paper, we present a laser-based acoustic technique for the characterization of multi-layer pillars. This non-contact technique has a high sensitivity for materials characterization with micron-scale spatial resolution. Absorption of laser light causes excitation of elastic waves that propagate through the pillar and are reflected by the pillar walls, exciting vibrational modes in the structure. We have demonstrated that our approach is sensitive to the thicknesses of individual layers in bi-layer and tri-layer copper pillar stacks. Focused ion beam scanning electron microscopy (FIB SEM) has been used to optimize the model and to validate the accuracy of the technique.

scholarly journals From Academia to Start-up: A Case Study with Implications for Engineering Education

2014 ◽  
Vol 4 (1) ◽  
pp. 24
Author(s):  
Bill Williams ◽  
José Figueiredo
Keyword(s):  
Knowledge Production ◽  
Critical Analysis ◽  
Qualitative Data ◽  
Engineering Students ◽  
Role Play ◽  
Engineering Practice ◽  
Start Up ◽  
Mode 2

This study uses the characterization of contrasting modes of knowledge production to follow the activity of a group of engineers who migrated from an academic environment to a successful start-up firm. Qualitative data from interviews of two key members of the team were used to characterize their activities in the two settings. The authors relate the engineering practice described in the interviews to the Gibbons Mode 1 and Mode 2 knowledge production phases and note the importance of a phase change in the transition between the two modes. The resultant case-study contributes material for use in role-play activity with engineering students to help develop interdisciplinary skills. The study also presents a critical analysis to evaluate the merits of the Mode 1 and Mode 2 framework for analysis of engineering practice at the level of the firm.

scholarly journals Applied Sciences Special Issue: Ultrasonic Guided Waves

2019 ◽  
Vol 9 (18) ◽  
pp. 3869 ◽  
Author(s):  
Clifford J. Lissenden
Keyword(s):  
Applied Sciences ◽  
Scientific Inquiry ◽  
Guided Waves ◽  
Ultrasonic Guided Waves ◽  
Special Issue ◽  
Practical Applications ◽  
Material State ◽  
Characterization Of Materials ◽  
Nondestructive Characterization

The propagation of ultrasonic guided waves in solids is an important area of scientific inquiry due primarily to their practical applications for the nondestructive characterization of materials, such as nondestructive inspection, quality assurance testing, structural health monitoring, and for achieving material state awareness [...]

scholarly journals Detecting and Facing Information Demand for New Target Groups such as Start-up Founders – A Case Study at the WHU Library

2019 ◽  
Vol 43 (1) ◽  
pp. 216-222
Author(s):  
Ragna Seidler-de Alwis ◽  
Julia Grefkes
Keyword(s):  
Applied Sciences ◽  
Information Science ◽  
Target Group ◽  
Specific Information ◽  
Target Groups ◽  
Information Demand ◽  
Start Up ◽  
University Of Applied Sciences ◽  
The Status

AbstractFuture oriented libraries can make use of the current start-up trend. An orientation towards new and unorthodox target groups can lead to an enhanced extension of demand and can emphasize the status of libraries. The library of the WHU – Otto Beisheim School of Management is considering to involve a new target group, start-up founders amongst their alumni. To that end, a survey was carried out and evaluated in cooperation with the Institute of Information Science at the TH Köln – University of Applied Sciences in form of a bachelor thesis, which this article is based upon. Here, a structured pre-analysis tries to determine the demand of this specific target group (founders) and develops a concept to serve the demand of this target group specifically. The example of the case study illustrates a method for target groups specific information demand and also checks the consequences for libraries and their services who venture out of their regular clientele.

scholarly journals Materials characterization of surfaces of water drops with surfactants by acoustic means: The need for a microgravity environment

1993 ◽  
Vol 93 (4) ◽  
pp. 2365-2365
Author(s):  
Robert E. Apfel ◽  
R. Glynn Holt ◽  
Yuren Tian ◽  
Xiaoyu Zheng ◽  
Shi Tao
Keyword(s):  
Materials Characterization ◽  
Microgravity Environment ◽  
Water Drops

scholarly journals Extraction and Characterization of Native Starch From Black and Red Rice

2020 ◽  
Vol 8 (3) ◽  
pp. 1
Author(s):  
Henrique Valentim Moura ◽  
Rennan Pereira de Gusmão ◽  
Thaisa Abrantes Souza Gusmão ◽  
Deise Souza de Castro ◽  
Raphael Lucas Jacinto Almeida ◽  
...  
Keyword(s):  
Lower Cost ◽  
Extraction Yield ◽  
Rice Starch ◽  
Sodium Metabisulfite ◽  
Red Rice ◽  
Black Rice ◽  
Alternative Source ◽  
Rice Grains ◽  
Starch Gels

The objective of the study is to extract and characterize red rice starch, a grain commonly consumed in the Northeast region of Brazil and to compare it with the starch obtained from black rice, widely spread in eastern countries. Starch was extracted by immersion of rice in sodium metabisulfite (0.2%), followed by milling, filtration, decantation and drying at 50 °C. The obtained starches were characterized by the following parameters: physicochemical, physical, rheological, textural, structural, thermal and morphological. The highest starch extraction yield was found in red rice grains (67.84%), where it obtained higher water absorption and lower apparent viscosity, firmness and gum. Both starch gels indicate the behavior of non-Newtonian fluid in the specific case of pseudoplastic crystallinity type A and with polyhedral geometry. For the thermal analysis of red rice starch, it was observed higher gelatinization temperature and lower gelatinization enthalpy. Black and red rice grains can be considered an alternative source of starch, especially red rice, which has a lower cost due to its production in the country.

scholarly journals Influence of Interactions among Polymeric Components of Automobile Shredder Residue on the Pyrolysis Temperature and Characterization of Pyrolytic Products

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1682 ◽  
Author(s):  
Bin Yang ◽  
Ming Chen
Keyword(s):  
Energy Recovery ◽  
Lower Cost ◽  
Pyrolysis Temperature ◽  
Pyrolysis Process ◽  
Shredder Residue ◽  
Gaseous Products ◽  
Automobile Shredder Residue ◽  
Gas Products

Pyrolysis and gasification have gradually become the main means to dispose of automobile shredder residue (ASR), since these methods can reduce the volume and quality of landfill with lower cost and energy recovery can be conducted simultaneously. As the ASR pyrolysis process is integrated, the results of pyrolysis reactions of organic components and the interaction among polymeric components can be clarified by co-pyrolysis thermogravimetric experiments. The results show that the decomposition mechanisms of textiles and foam are markedly changed by plastic in the co-pyrolysis process, but the effect is not large for rubber and leather. This effect is mainly reflected in the pyrolysis temperature and pyrolysis rate. The pyrolytic trend and conversion curve shape of the studied ASR can be predicted by the main polymeric components with a parallel superposition model. The pyrolytic product yields and characterizations of gaseous products were analyzed in laboratory-scale non-isothermal pyrolysis experiments at finished temperatures of 500 °C, 600 °C, and 700 °C. The results prove that the yields of pyrolytic gas products are determined by the thermal decomposition of organic substances in the ASR and final temperature.

Characterization of the start-up of single and two-stage Anammox processes with real low-strength wastewater treatment

Chemosphere ◽  
2020 ◽  
Vol 245 ◽  
pp. 125572 ◽  
Author(s):  
Peng Wu ◽  
Xingxing Zhang ◽  
Xinzhu Wang ◽  
Chaochao Wang ◽  
Fangnigbe Faustin ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Two Stage ◽  
Start Up ◽  
Low Strength
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