Design of equipment for lunar dust removal

NASA has a long range goal of constructing a fully equipped, manned lunar base on the near side of the moon by the year 2015. During the Apollo Missions, lunar dust coated and fouled equipment surfaces and mechanisms exposed to the lunar environment. In addition, the atmosphere and internal surfaces of the lunar excursion module were contaminated by lunar dust which was brought in on articles passed through the airlock. Consequently, the need exists for device or appliance to remove lunar dust from surfaces of material objects used outside of the proposed lunar habitat. Additionally, several concepts were investigated for preventing the accumulation of lunar dust on mechanisms and finished surfaces. The character of the dust and the lunar environment present unique challenges for the removal of contamination from exposed surfaces. In addition to a study of lunar dust adhesion properties, the project examines the use of various energy domains for removing the dust from exposed surfaces. Also, prevention alternatives are examined for systems exposed to lunar dust. A concept utilizing a pressurized gas is presented for dust removal outside of an atmospherically controlled environment. The concept consists of a small astronaut/robotic compatible device which removes dust from contaminated surfaces by a small burst of gas

The 1991-1992 project summaries

The Department of Mechanical Engineering at The University of Texas at Austin participated in seven cooperative design projects this year. Six of the projects were associated with the Johnson Space Center and include the design of a thermal control system for an inflatable lunar habitat module, a vibration isolation system for a space shuttle cycle ergometer, a radiator shading device for a lunar outpost, a reusable astronaut safety tether, a resistive exercise device for use on the space shuttle, and a fleet of autonomous regolith throwing devices for radiation shielding of lunar habitats. The seventh project is associated with the Jet Propulsion Lab and involves the design of a shock absorbing wheel for a small six-wheeled Martian rover vehicle

Oxidation of Strong C-H Bonds by a Powerful O2-Derived Iron(IV)-Oxo Species

University of Minnesota Ph.D. dissertation. December 2015. Major: Chemistry. Advisor: Lawrence Que, Jr.. 1 computer file (PDF); xvi, 98 pages.Dioxygen plays a crucial role in the metabolic processes of living organisms, as both its formation and activation are essential to maintaining life. Nonheme iron enzymes catalyze an amazing array of oxidation reactions utilizing O2 under mild conditions. Understanding the mechanisms by which nature is able to utilize dioxygen to perform these transformations is of great interest both on a fundamental and practical level. To this end, synthetic systems have been employed to gain in-depth mechanistic insight. The tridentate ligand TpPh2 (TpPh2 = hydrotris(3,5-diphenylpyrazol-1-yl)borate) has been previously used as a synthetic model for the 2-His-1-carboxylate active sites of nonheme iron oxygenases. Addition of an α-keto carboxylate provides a five-coordinate complex that, upon addition of oxygen, undergoes oxidative decarboxylation of the α-keto acid with concomitant self-hydroxylation of a single ortho position of a ligand phenyl ring, thus acting as a functional mimic of α-KG-dependent dioxygenases. As in α-KG-dependent dioxygenases, a Fe(IV)=O species is proposed to be the oxidant that carries out ligand self-hydroxylation. This work focuses on attempts to intercept the reactive iron-oxygen species with hydrocarbons with varying C-H bond dissociation energies (BDE), including n-butane. The reactions were analyzed to identify oxidation products and assess the oxidative power of the putative Fe(IV)=O oxidant. The first step in the activation of O2 by non-heme iron enzymes is usually the formation of an Fe(III)-superoxo species upon binding of O2 to the Fe(II) center and subsequent electron transfer. Such species are well characterized in the enzymatic and synthetic heme literature, but only recently have iron-superoxo species been trapped and characterized in nonheme iron enzymes. In this thesis is reported the characterization of the first synthetic mononuclear nonheme Fe(III)-superoxo species by bubbling O2 into a solution of Fe(II)(BDPP) (BDPP = 2,6-Bis(((S)-2-(diphenylhydroxymethyl)-1-pyrrolidinyl)methyl)pyridine) at -80 °C and its conversion to a Fe(III)-hydroperoxo species through H-atom abstraction and then to a diferric-peroxo species via comproportionation. Heterobimetallic centers are also involved in oxygen metabolism. In this thesis is reported the characterization of two nonheme heterobimetallic Fe-O-M species: a FeIII-O-CrIII species generated from dioxygen activation and a FeIV-O-CeIV intermediate generated during iron-catalyzed water oxidation

Assessment of the granulosis virus of Cydia pomonella L. (CpGV) as a tool to control the pea moth Cydia nigricana F. in grain peas

C. nigricana verursachte in den letzten Jahren erhebliche Schäden in der Gemüseerbsenproduktion. Da es bisher im ökologischen Anbau keine wirksame Regulierungsoption für C. nigricana gibt, sollte die Direktbekämpfung mit dem Apfelwicklergranulosevirus (CpGV) geprüft werden. Payne (1981) stellte bereits in Laborversuchen eine Empfindlichkeit von C. nigricana gegen das Apfelwicklergranulosevirus CpGV fest, der LC50 Wert von CpGV gegen Erstlarven lag hierbei bei Fraßtests im Labor bei der 10-fachen Konzentration gegen C. pomonella (1,90 × 105 im Vergleich zu 1,54 × 104 Partikel/ml). Geissler (1994) erreichte in Freilandversuchen durch den Einsatz des Virus Befallsreduktionen von 72% mit den im Apfelanbau üblichen Konzentrationen.In Germany pea moth (Cydia nigricana, Lepidoptera: Tortricidae) is a serious problem especially for organic vegetable peas. CpGV is a natural virus causing death in Cydia pomonella. The virus does not act by contact, but ingestion. Small scale field-tests with CpGV were conducted according to EPPO-guidelines with grain pea cv. "Santana" in a randomised block design in 4 replicates. At the time of egg hatching peas were sprayed with CpGV. Efficacy assessments were based on the percentage of damaged peas, the numbers of larvae per pod, larval stage and yield loss. In 2004 an UV-protection powder combined with CpGV was tried unsuccessfully. Even very high application rates of CpGV did not result in a significant reduction of pea moth larvae in the pods, rendering CpGV not useful for their control under the conditions tested

Light microscopic studies on the development of Beauveria bassiana and other putative endophytes in leaf tissues

Die vorliegende Untersuchung beinhaltete sechs Testpilze, über die in der Literatur Berichte als Endophyten vorliegen (Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea, Trichoderma harzianum, Fusarium proliferatum, Chaetomium globosum), zwei phytopathogene Pilze (Ascochyta fabae, Plenodomus lingam) und vier Wirtspflanzen (Vicia faba, Brassica napus, Phaseolus vulgaris, Zea mays). Die Konidien oder Blastosporen bzw. Ascosporen der Testpilze wurden durch Sprühen auf die Blatt­ober­fläche oder durch Infiltration durch die Spaltöffnungen appliziert. Die lichtmikroskopische Untersuchung zeigte, dass die Sporen auf der Blattoberfläche auskeimten, aber nicht aktiv in die Blätter eindrangen. Im Blatt­inneren schienen Sporenkeimung und Hyphenwachstum auf Bereiche mit Zell- bzw. Gewebeschädigung beschränkt zu sein. Verschiedene Wirtsreaktionen wurden beobachtet, wie die Verbräunung von Epidermiszellen und die Bildung von Papillen. Eine Besiedlung des Gewebes vergleichbar der mit den Pathogenen A. fabae (bei Ackerbohne) und P. lingam (bei Raps) wurde nicht beobachtet. Erst nach Auslegen von inokuliertem Blattmaterial auf Agarmedium setzten Sporenkeimung und Hyphenwachstum im Blattinneren ein. Die Ergebnisse deuten eher auf eine saprotrophe als auf eine endophytische Lebensweise der untersuchten Pilze im Blattgewebe der untersuchten Wirtspflanzen hin.The study involved six test fungi previously recorded in the literature as being endophytes (Beauveria bassiana, Metarhizium anisopliae, Isaria fumosorosea, Trichoderma harzianum, Fusarium proliferatum, Chaetomium globosum), two plant pathogenic fungi (Ascochyta fabae, Plenodomus lingam) and four host plants (Vicia faba, Bras­sica napus, Phaseolus vulgaris, Zea mays). Aerial conidia, blastospores, or ascospores, respectively were applied to leaf surfaces by spraying or by infiltrating spore suspensions through stomata directly into the leaves. Obser­vations using light microscopy showed that the test fungi germinated on the leaf surface but did not enter actively into the leaves. Within the leaves, germination of spores and growth of hyphae appeared to depend on the presence of damaged plant tissue. Various host reactions such as browning of epidermal cells and formation of papillae were observed. Colonization of healthy leaves by the test fungi in a manner similar to the pathogens A. fabae (on Faba bean) and P. lingam (on oilseed rape) was not observed. Spore germination and hyphal growth commenced when inoculated leaves were placed on agar medium. The results indicate that the test fungi possessed a saprotrophic rather than an endo­phytic life style when associated with leaf tissue of the studied hosts

Biology of the black rot pathogen, Guignardia bidwellii, its development in susceptible leaves of grapevine Vitis vinifera

Seit 2002 / 2003 tritt die durch den Ascomyceten Guignardia bidwellii hervorgerufene Schwarzfäule regelmäßig in ökologisch bewirtschafteten Weinbergen an Mosel, Nahe und im Mittelrheintal auf. Obwohl die Krankheit, ursprünglich aus den USA kommend, schon seit über 100 Jahren in Südeuropa bekannt ist, ist das Wissen über die Biologie von G. bidwellii noch immer lückenhaft. In der vorliegenden Arbeit wird der Lebenszyklus von G. bidwellii mit histologisch-mikroskopischen Methoden (Durchlicht-, Fluoreszenz- und Elektronenmikroskopie) untersucht. Die Entwicklung des Pilzes in einer anfälligen Rebsorte (Riesling) wird von der Sporenkeimung bis zur Ausbildung der Pyknidien und Pseudothezien verfolgt. Der Schwerpunkt der Arbeit liegt auf der Entwicklung nach dem Eindringen in den Wirt, die durch subcuticuläres Wachstum charakterisiert ist. Ziel ist die Verbreiterung der Wissensbasis über die Biologie von G. bidwelli sowie die Erarbeitung einer Grundlage für die Entwicklung effizienter Bekämpfungsmethoden und eine histologische Charakterisierung der Sortenresistenz.Since 2002 / 2003 black rot caused by Guignardia bidwellii is regularly occurring in organic viticulture in the wine growing areas at the Mosel and Nahe River and in the Middle Rhine valley in Germany. Though the disease originates from the USA and is known in Europe already for more than 100 years, the knowledge about the biology of its causal organism is still scanty. In the present study the life cycle of G. bidwellii is analysed with histological microscopical methods (bright field, phase contrast, fluorescence and electron microscopy). The development of the fungus on a susceptible grapevine variety (Riesling) is followed from spore germination up to the development of pycnidia and pseudothecia. The study is focused on the phase after penetration of the fungus which is characterized by subcuticular spread. The aim is to broaden the knowledge of the biology of G. bidwellii, to provide the basis for efficient control measures and to enable the histological characterization of varietal resistance

In situ immunofluorescence localization: A method for rapid detection of Beauveria spp. in the rhizosphere of Quercus robur saplings

Zur biologischen Bekämpfung von Pflanzenschädlingen, z.B. Maikäfer-Engerlingen, in der Rhizosphäre von Eichen, Apfelbäumen oder Kiefern werden zunehmend entomopathogene Beauveria-Spezies eingesetzt. Für eine erfolgreiche Anwendung ist es wichtig, die Ausbreitung und Persistenz der ausgebrachten Pilze qualitativ und quantitativ zu erfassen. Die Bestimmung beider Größen durch Ausplattieren auf selektiven Nährmedien oder durch mole­kulare Methoden wie PCR ist mühsam und oft ungenügend. Ziel der vorliegenden Studie war daher, eine spezifische In-situ-Methode durch Immunfluoreszenzmarkierung von Beauveria spp. zu entwickeln, hier an jungen Feinwurzeln dreijähriger Stieleichen. Durch Anfärben mit dem unspezifischen Farbstoff Blankophor wurde sichtbar, dass alle untersuchten Feinwurzeln ein dichtes Netz von Bodenpilzen trugen. Polyklonale Beauveria-Antikörper markierten an nicht beimpften Wurzeln keinen dieser natürlich wachsenden Pilze. Mit Beauveria brongniartii beimpfte Wurzeln zeigten bis zu zehn Monate nach der Inokulation eine spezifische Markierung. Während die natürlich vorkommenden Rhizosphären-Pilze in den Interzellularräumen der Wurzelrinde wuchsen, waren Hyphen von inokulierter B. brongniartii nie im Wurzelgewebe zu finden, sondern nur oberflächlich auf der Rhizodermis. Diese Beobachtungen zeigen, dass B. brongniartii bei Eichenwurzeln nicht endophytisch wächst, und dass die verwendete Methode die Unterscheidung von B. brongniartii von der in der Eichen-Rhizosphäre lebenden Pilzflora ermöglicht. Immunfluoreszenzmarkierung, wie in der aktuellen Studie eingesetzt, kann eine nützliche Methode sein, um B. brongniartii in der Rhizosphäre nachzuweisen und quantitativ zu erfassen und somit eine Langzeitkontrolle von Schädlingen mit Entomopathogenen zu ermöglichen.For biological control of plant pests, e.g. cockchafer grubs, in the rhizosphere of oak, apple or pine trees, ento­mopathogenic Beauveria spp. are increasingly applied. For successful use, it is important to monitor the spread and persistence of the inoculated fungi, both qualitati­vely and quantitatively. The determination of both para­meters by plating on selective nutrient media or by mole­cular methods such as PCR of soil samples are quite laborious and often do not yield satisfactory results. Therefore, the aim of the present study was to develop a spe­cific in situ method using immunofluorescence labelling of Beauveria spp. growing on young fine roots of three-year old oak saplings. All fine roots investigated were covered with a dense net of soil rhizosphere fungi, as visua­lized by staining with the nonspecific dye blankophor. On non-inoculated roots, polyclonal Beauveria anti­bodies did not label any of these naturally growing fungi. Only samples of roots inoculated with Beauveria brongniartii displayed specific labelling up to ten months after inocu­lation. Whereas the natural rhizosphere fungi were detected growing in the intercellular space of the root cortex in an ectomycorrhiza-like manner up to the endodermis, hyphae of the inoculated B. brongniartii were never seen within the root tissue but only growing on the surface of the rhizodermis. These observations indicate that B. brongniartii does not grow endophytically, and that the method used allows to discriminate B. brongniartii from the resident fungal flora in the oak tree rhizosphere. Detection by immunofluorescence labelling employed in the current study may be a useful tool to follow B. brongniartii in experiments aimed at establishing the entomopathogen in the rhizosphere and to monitor its fate in long-term control of entomopathogens