Electrostatic Screen for Transport of Martian and Lunar Regolith

The Martian and Lunar Regolith contain fine particulate including those in the size range from 0.5 to 200 micron [1-2]. Martian dust can be transported and deposited by Aeolian processes, including "Dust Devils". Due to the ultra high vacuum (10e-12 Torr), transport of dust on the Moon is solely a result of collision/ballistic motion. Dust obscuration of solar cells is one of the primary factors limiting the duration of Martian missions, including the Mars Exploration Rovers. Dust contamination in vacuum seals is one of the primarily factors that limited lunar excursions during the Apollo missions. Controlled transportation of dust on Mars and the Moon is important for many reasons, including both contamination mitigation and in situ resource utilization (ISRU). Since both the monopole and dipole electrostatic moments result in non-trivial forces on particles in an electrostatic field, dust particles, whether charged or not, can be transported by electrostatic fields. In the electrostatic screen, alternating waveforms of voltage applied to patterned grids of electrodes will transport dust. The authors will show that the canonical methods for transporting dust via electrostatic screen can be readily applied to transport of Martian and Lunar regolith. Experiments have been performed in ambient, low humidity, Martian, and Lunar conditions. Screen parameters have been examined for application to each regolith, such as grid spacing, trace width, grid voltage, pulse pattern, pulse frequency, and coating type. The authors have also developed an electrostatic screen based on optically transparent conductors that can be placed over solar arrays, windows, visors, lenses, etc

Degradation of Organics in a Glow Discharge Under Martian Conditions

The primary objective of this project is to understand the consequences of glow electrical discharges on the chemistry and biology of Mars. The possibility was raised some time ago that the absence of organic material and carbonaceous matter in the Martian soil samples studied by the VikinG Landers might be due in part to an intrinsic atmospheric mechanism such as glow discharge. The high probability for dust interactions during Martian dust storms and dust devils, combined with the cold, dry climate of Mars most likely results in airborne dust that is highly charged. Such high electrostatic potentials generated during dust storms on Earth are not permitted in the low-pressure CO2 environment on Mars; therefore electrostatic energy released in the form of glow discharges is a highly likely phenomenon. Since glow discharge methods are used for cleaning and sterilizing surfaces throughout industry, the idea that dust in the Martian atmosphere undergoes a cleaning action many times over geologic time scales appears to be a plausible one

Damage progression in compressively loaded laminates containing a circular cutout

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76038/1/AIAA-10597-113.pd

Electrodynamic Dust Shield for Surface Exploration Activities on the Moon and Mars

The Apollo missions to the moon showed that lunar dust can hamper astronaut surface activities due to its ability to cling to most surfaces. NASA's Mars exploration landers and rovers have also shown that the problem is equally hard if not harder on Mars. In this paper, we report on our efforts to develop and electrodynamic dust shield to prevent the accumulation of dust on surfaces and to remove dust already adhering to those surfaces. The parent technology for the electrodynamic dust shield, developed in the 1970s, has been shown to lift and transport charged and uncharged particles using electrostatic and dielectrophoretic forces. This technology has never been applied for space applications on Mars or the moon due to electrostatic breakdown concerns. In this paper, we show that an appropriate design can prevent the electrostatic breakdown at the low Martian atmospheric pressures. We are also able to show that uncharged dust can be lifted and removed from surfaces under simulated Martian environmental conditions. This technology has many potential benefits for removing dust from visors, viewports and many other surfaces as well as from solar arrays. We have also been able to develop a version of the electrodynamic dust shield working under. hard vacuum conditions. This version should work well on the moon

1952: Abilene Christian College Bible Lectures - Full Text

Delivered in the Auditorium of Abilene Christian College, February, 1952 ABILENE, TEXAS PRICE, $3.00 firm foundation publishing house Box 77 Austin Cl, Texa

1928-29: Abilene Christian College Bible Lectures - Full Text

INTRODUCTION It has been the custom of Abilene Christian College for several years to hold an annual “Lectureship” the last week in February. This is a time of gathering of brethren from all over the state and adjoining states. It is a time of a great spiritual feast. It affords an opportunity for brethren to meet and talk over the work of the Lord. It also enables us to hear again great men of God whose voices have sounded the Word of the Lord in the days of the past in great meetings. In order that those who are not permitted to hear the lectures may enjoy them it has been the custom of Abilene Christian College to publish the lectures in a book at the end of each two years. We feel that these wonderful messages from some of the greatest minds of the church ought to be preserved that they may do good even after the lips of the speakers have become silent. It is with a prayer that great good may come that this volume of lectures of 1928 and 1929 is sent forth. We regret that some of the lectures could not be included in the book. Several of the brethren neglected to send in their manuscripts; some other manuscripts were destroyed by fire, and the brethren did not replace them. Most\u27 of the lectures are in the book. BATSELL BAXTER. DELIVERED IN THE AUDITORIUM OF ABILENE CHRISTIAN COLLEGE ABILENE, TEXAS FEBRUARY 1928-1929 FIRM FOUNDATION PUBLISHING HOUSE 104-106-108 E. 9th Street Austin, Texas

Buckling and Failure of Compression-loaded Composite Cylindrical Shells with Reinforced Cutouts

Results from a numerical and experimental study that illustrate the effects of selected cutout reinforcement configurations on the buckling and failure response of compression-loaded composite cylindrical shells with a cutout are presented. The effects of reinforcement size, thickness, and orthotropy on the overall response of compression-loaded shells are described. In general, reinforcement around a cutout in a compression-loaded shell can retard or eliminate the local buckling response and material failure near the cutout and increase the buckling load of the shell. However, some results show that certain reinforcement configurations can cause a significant increase in the local interlaminar failures that can accumulate near the free edges of a cutout during a local buckling event

The role of clathrin in post-golgi trafficking in toxoplasma gondii

Apicomplexan parasites are single eukaryotic cells with a highly polarised secretory system that contains unique secretory organelles (micronemes and rhoptries) that are required for host cell invasion. In contrast, the role of the endosomal system is poorly understood in these parasites. With many typical endocytic factors missing, we speculated that endocytosis depends exclusively on a clathrin-mediated mechanism. Intriguingly, in Toxoplasma gondii we were only able to observe the endogenous clathrin heavy chain 1 (CHC1) at the Golgi, but not at the parasite surface. For the functional characterisation of Toxoplasma gondii CHC1 we generated parasite mutants conditionally expressing the dominant negative clathrin Hub fragment and demonstrate that CHC1 is essential for vesicle formation at the trans-Golgi network. Consequently, the functional ablation of CHC1 results in Golgi aberrations, a block in the biogenesis of the unique secretory microneme and rhoptry organelles, and of the pellicle. However, we found no morphological evidence for clathrin mediating endocytosis in these parasites and speculate that they remodelled their vesicular trafficking system to adapt to an intracellular lifestyle

Framing the neoliberal canon: resisting the market myth via literary enquiry

here is widespread recognition that neoliberal rhetoric about ‘free markets’ stands in considerable tension with ‘really existing’ neoliberalizing processes. However, the oft-utilized analytical distinction between ‘pure’ economic and political theory and ‘messy’ empirical developments takes for granted that neoliberalism, at its core, valorizes free markets. In contrast, the paper explores whether neoliberal intellectuals ever made such an argument. Using Friedrich Hayek and Milton Friedman as exemplars, our reading of canonical neoliberal texts focuses on author framing gestures, particular understandings of the term ‘science’, techniques of characterization, and constructions of epistemological legitimacy. This enables us to avoid the trap of assuming that these texts are about free markets and instead enquires into their constitution as literary artefacts. As such, we argue that the remaking of states and households rather than the promotion of free markets is at the core of neoliberalism. Our analysis has significant implications. For example, it means that authoritarian neoliberalism is not a departure from but actually more in line with the ‘pure’ neoliberal canon than in the past. Therefore, neoliberalism ought to be critiqued not for its rhetorical promotion of free markets but instead for seeking to reorganize societies in coercive, non-democratic and unequal ways. This also enables us to acknowledge that households are central to resistance to neoliberalism as well as to the neoliberal worldview itself

Interleukin-17D and Nrf2 mediate initial innate immune cell recruitment and restrict MCMV infection.

Innate immune cells quickly infiltrate the site of pathogen entry and not only stave off infection but also initiate antigen presentation and promote adaptive immunity. The recruitment of innate leukocytes has been well studied in the context of extracellular bacterial and fungal infection but less during viral infections. We have recently shown that the understudied cytokine Interleukin (IL)-17D can mediate neutrophil, natural killer (NK) cell and monocyte infiltration in sterile inflammation and cancer. Herein, we show that early immune cell accumulation at the peritoneal site of infection by mouse cytomegalovirus (MCMV) is mediated by IL-17D. Mice deficient in IL-17D or the transcription factor Nuclear factor (erythroid-derived 2)-like 2 (Nrf2), an inducer of IL-17D, featured an early decreased number of innate immune cells at the point of viral entry and were more susceptible to MCMV infection. Interestingly, we were able to artificially induce innate leukocyte infiltration by applying the Nrf2 activator tert-butylhydroquinone (tBHQ), which rendered mice less susceptible to MCMV infection. Our results implicate the Nrf2/IL-17D axis as a sensor of viral infection and suggest therapeutic benefit in boosting this pathway to promote innate antiviral responses