A baseline lunar mine

A models lunar mining method is proposed that illustrates the problems to be expected in lunar mining and how they might be solved. While the method is quite feasible, it is, more importantly, a useful baseline system against which to test other, possible better, methods. Our study group proposed the slusher to stimulate discussion of how a lunar mining operation might be successfully accomplished. Critics of the slusher system were invited to propose better methods. The group noted that while nonterrestrial mining has been a vital part of past space manufacturing proposals, no one has proposed a lunar mining system in any real detail. The group considered it essential that the design of actual, workable, and specific lunar mining methods begin immediately. Based on an earlier proposal, the method is a three-drum slusher, also known as a cable-operated drag scraper. Its terrestrial application is quite limited, as it is relatively inefficient and inflexible. The method usually finds use in underwater mining from the shore and in moving small amounts of ore underground. When lunar mining scales up, the lunarized slusher will be replaced by more efficient, high-volume methods. Other aspects of lunar mining are discussed

To build a mine: Prospect to product

The terrestrial definition of ore is a quantity of earth materials containing a mineral that can be extracted at a profit. While a space-based resource-gathering operation may well be driven by other motives, such an operation should have the most favorable cost-benefit ratio possible. To this end, principles and procedures already tested by the stringent requirements of the profit motive should guide the selection, design, construction, and operation of a space-based mine. Proceeding from project initiation to a fully operational mine requires several interacting and overlapping steps, which are designed to facilitate the decision process and insure economic viability. The steps to achieve a fully operational mine are outlined. Presuming that the approach to developing nonterrestrial resources will parallel that for developing mineral resources on Earth, we can speculate on some of the problems associated with developing lunar and asteroidal resources. The baseline for our study group was a small lunar mine and oxygen extraction facility. The development of this facility is described in accordance with the steps outlined

Asteroid mining

The earliest studies of asteroid mining proposed retrieving a main belt asteroid. Because of the very long travel times to the main asteroid belt, attention has shifted to the asteroids whose orbits bring them fairly close to the Earth. In these schemes, the asteroids would be bagged and then processed during the return trip, with the asteroid itself providing the reaction mass to propel the mission homeward. A mission to one of these near-Earth asteroids would be shorter, involve less weight, and require a somewhat lower change in velocity. Since these asteroids apparently contain a wide range of potentially useful materials, our study group considered only them. The topics covered include asteroid materials and properties, asteroid mission selection, manned versus automated missions, mining in zero gravity, and a conceptual mining method

Effect of Water Ice Content on Excavatability of Lunar Regolith

The amount of water ice contained within prepared samples of JSC-1 lunar regolith simulant strongly affects the excavatability of the material. As part of a NASA Phase I SBIR project, load-penetration testing of JSC-1 lunar regolith simulant was performed at water ice concentrations ranging from zero to 11% by mass (approximately saturated), after compaction and cooling to simulate probable lunar conditions. After mixing dry JSC-1 simulant with the appropriate amount of water, the samples were individually compressed into containment rings under 48 MPa of pressure. Thermocouples embedded in the samples monitored internal temperature while they were cooled in a bath of liquid nitrogen. At temperatures corresponding to the lunar polar cold traps, a 19mm-diameter hemispherical indenter was forced into the center of each sample while the required force and the resulting penetration were recorded. The results show strong sensitivity to water content. Regolith containing up to 0.3% water ice is very easy to excavate and behaves like weak coal. Regolith with 0.6 to 1.5% ice is readily excavatable and acts like weak shale or mudstone. Regolith with ~8.4% ice would be excavated with mechanical excavators, much like moderate-strength limestones, sandstones, and shales. The highest strength mix (~10.6% ice) behaves like strong limestone or sandstone, which require massive excavators. These results show that realistically compacted ice-regolith mixtures may be harder to excavate than previously believed, and that mixture variability must be well-understood to design effective excavators

The Differences Between Women and Men in the Length of Time Between Onset of Cardiac Symptoms and Undergoing a Cardiac Catheterization

Coronary artery disease is a leading cause of death among women. Even so, research suggests that women continue to receive less aggressive cardiac treatment than men. The purpose of the research was to determine if there was a time difference in initiation of cardiac catheterization in a selected population of men and women. A chart review was completed on adult women (n=20) and men (n=20), with varied adult ages, at a hospital based cardiac catheterization laboratory in Northern California. The charts were chosen randomly from the daily catheterization list. Data collection included age, gender, preferred spoken language, pay source, prior documented cardiac testing, history and physical, time and date when onset of signs and symptoms of cardiac disease began, and the time and date when cardiac catheterization was performed. The study failed to identify a difference between women and men in the length of time between onset of cardiac symptoms and undergoing a cardiac catheterization. However, the study did reveal a difference in presenting symptoms between men and women

Determinants of wage satisfaction

The role of sensitivity to social comparison information was investigated with regard to perceptions of equity and subsequent satisfaction with pay. Subjects were 64 undergraduate students. A 2 x 2 x 2 factorial design was employed. The three factors were (a) Equity, (b) Adequacy of pay, and (c) Sensitivity to social comparison information. Predicted main effects of equity and adequacy of pay on wage satisfaction were found. A predicted interaction of Equity x Sensitivity to Social Comparison Information was not found. Interpretation of the failure of this prediction focused on the personality scale employed

Percussive Penetration of Unconsolidated Granular Media in a Laboratory Setting

This controlled study examined the feasibility of a simple percussive approach to drilling through unconsolidated regolith deposits on Mars. The experiments showed that the approach is feasible at the low power levels and low confining pressures used, and that the rate of impact is more important to the penetration rate than is the mass of the impactor (hammer). More massive impactors tend to lower energy efficiency, as they do in terrestrial pile-driving. Unexpectedly, penetration plotted against applied energy tends to cluster into parallel linear trends. Within a given cluster, penetration is very sensitive to applied energy, while between clusters, the same penetration requires different energy levels. The clusters are separated by gaps whose widths may be related to the average grain size of the material being penetrated. The layered nature of natural sedimentary deposits is reflected in the cumulative energy-penetration plots, which could thus serve to record bedding thickness and frequency during Mars exploration. This study has shown that percussive drilling using a down-the-hole hammer design may be feasible in unconsolidated fine regolith near the ground surface

Wenn bei der Geburt nicht nur das Kind kommt : eine Arbeit über lustvolle sexuelle Stimulation sub partu und deren Auswirkung auf die physiologischen Geburtsprozesse

Hintergrund: Die Geburt kann als Vollendung des sexuellen Kontaktes und Teil der weiblichen Sexualität verstanden werden. In Zeiten der hochtechnisierten und medikalisierten Geburtshilfe sind diese Ansichten in den Hintergrund gerückt. Dennoch gibt es Frauen, die sich bewusst für eine lustvolle, sexuelle Geburt entscheiden. Ziel: In dieser themengeleiteten Arbeit soll eruiert werden, inwiefern physiologische Geburtsvorgänge durch subpartale sexuelle Handlungen von werdenden Müttern beeinflusst werden können. Anhand von Geburtsberichten werden Bedürfnisse und Sichtweisen aufgezeigt und Praxisempfehlungen abgeleitet. Methode: Zur Beantwortung der Fragestellung wird eine Literaturrecherche durchgeführt. Die Daten aus zwei qualitativen Studien, einem Review, einem Fachbuch, einem Ratgeber und vier Erfahrungsberichten werden analysiert und diskutiert. Ergebnisse: Die Schmerzempfindung kann vermindert, die Wehentätigkeit verstärkt und das Geburtserlebnis verbessert werden. Dies ist auf endokriner und nervaler Ebene erklärbar. In den Geburtsberichten wird die Wichtigkeit von Geburtsatmosphäre, Geburtsort und Haltung des Fachpersonals betont. Schlussfolgerungen: Subpartale sexuelle Stimulation und Orgasmen könnten eine kostenfreie und alternativmedizinische Ergänzung zu bereits existierenden analgetischen und wehenfördernden Methoden darstellen. Dazu besteht jedoch weiterer Forschungsbedarf. Die Hebamme nimmt eine Schlüsselrolle im intimen Geburtssetting ein und soll daher ihre Haltung kontinuierlich reflektieren