Kleines und leichtes Gasmesssystem für unbemannte Starrflügler-Forschungsflugzeuge

2021 ◽  
Author(s):  
Hasan Mashni ◽  
Yann-Georg Buechau ◽  
Jakob Boventer ◽  
Martin Schön ◽  
Serg Van-der-poel ◽  
...  
Keyword(s):  
System F

<p>Die Fähigkeit, CO2- und andere Gasemissionen zu reduzieren, um die globalen Emmisionsziele und Luftqualitätsstandards einzuhalten, erfordert auch die räumlich und zeitlich möglichst hoch auflösende Messung der Gasquellen und -senken sowie die Gastransportmechanismen.</p> <p>Satellitengestützte Fernerkundungen sind in der Regel räumlich nur grob auflösend, dies betrifft insbesondere bodennahe Vertikalprofile. Auch die Erfassung der zeitlichen Variabilität durch Satelliten ist limitiert, da eine große Anzahl von Satelliten notwendig ist, um einen Tagesgang vollständig zu erfassen. Je nach Sensorsystem können Satelliten nur Messungen während des Tages durchführen, da die Sensoren auf die Rückstreuung der Infrarotstrahlung der Sonne angewiesen sind. Bodengestützte Gasfernerkundung wiederum ist stationär gebunden und auch in der räumlichen Auflösung limitiert, wenn der Einfluss von turbulenten Prozessen und Transport untersucht werden soll.</p> <p>Eine Lösung zur Schließung dieser Datenlücke können in-situ Messungen mittels unbemannter Flugssysteme (UAS) sein, auch um zusätzlich zu stationären Bodenmessungen Gasverteilung und Konzentrationen räumlich aufgelöst in der unter Atmosphäre zu messen. Besonders der Einsatz von Starrflügler UAS ermöglicht - im Vergleich zu den heute vielfach verwendeten Multikopter UAS - längere Flugzeiten und Reichweiten bei nur geringen Störungen des Strömungsfeld bzw. der gemessenen Gasvolumina.</p> <p>Die vorliegende Studie präsentiert ein leichtes, kleines, kostengünstiges NDIR-CO2-Sensors-System für den universellen Einsatz an Bord von Starrflügel UAS. Der Gassensor ist in ein aerodynamisches Gehäuse integriert, der sog. "Egg-Pod", welches mittels additiver Fertigung (hauptsächlich in handelsüblichen 3D Druckern) hergestellt wird. Das Gehäuse ist so konzipiert, dass dessen Form als passive Pumpe und Gasmesskammer während des Fluges fungiert. Der kostengünstige Ansatz (von Sensor und Gehäuse) lässt sich vor allem durch seinen einfachen Aufbau auf andere mobile Plattformen übertragen und ist für weitere Gassensorik skalierbar. Zur Charakterisierung unseres hier vorgestelltem Messsystems wurde der nächtliche CO2-Schichtungseffekt vermessen. Der nächtliche, bodennahe Aufbaueffekt von CO2 aufgrund der Bodenabkühlung bei Strahlungswetterlagen und der dabei auftretende räumliche Gradient wurde genutzt, um das Auflösungsvermögen des Systems zu charakterisieren. Hierzu wurden Flugmessungen mit den CO2 Messungen auf dem Messturm des Meteorologischen Observatoriums Lindenberg - Richard Aßmann-Observatorium (Deutscher Wetterdienst DWD) verglichen. </p>

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Electron Probe Analysis of Muscle

1982 ◽  
Vol 40 ◽  
pp. 398-401
Author(s):  
A. V. Somlyo ◽  
H. Shuman ◽  
A. P. Somlyo
Keyword(s):  
Skeletal Muscle ◽  
Smooth Muscle ◽  
Sarcoplasmic Reticulum ◽  
Resting State ◽  
Binding Sites ◽  
Electron Probe ◽  
Frog Skeletal Muscle ◽  
Electron Probe Analysis ◽  
Probe Analysis

Electron probe analysis of frozen dried cryosections of frog skeletal muscle, rabbit vascular smooth muscle and of isolated, hyperpermeab1 e rabbit cardiac myocytes has been used to determine the composition of the cytoplasm and organelles in the resting state as well as during contraction. The concentration of elements within the organelles reflects the permeabilities of the organelle membranes to the cytoplasmic ions as well as binding sites. The measurements of [Ca] in the sarcoplasmic reticulum (SR) and mitochondria at rest and during contraction, have direct bearing on their role as release and/or storage sites for Ca in situ.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

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