Design study of large area 8 cm x 8 cm wrapthrough cells for space station

The design of large area silicon solar cells for the projected NASA space station is discussed. It is based on the NASA specification for the cells which calls for an 8 cm by 8 cm cell of wrapthrough type with gridded back contacts. The beginning of life (BOL) power must be 1.039 watts per cell or larger and maximum end of life (EOL) after 10 years in the prescribed orbit under an equivalent 1MeV electron radiation damage fluence of 5 times 10 to the 13th power e/square cm. On orbit efficiency is to be optimized by a low thermal absorptance goal (thermal alpha) of .63

R. v. Butler: Recognizing the Expressive Value and the Harm in Pornography

The recent Canadian Supreme Court decision of R. v. Butler recognizes and addresses the harmful anti-social attitudes and behaviors towards women which are perpetuated by misogynistic, violent pornography. Meanwhile, American courts continue to grapple with their traditional obscenity standard. This comment presents an overview of the American approach to regulating and categorizing pornography, and explores the obstacles this approach creates for addressing the issues of harm to women. The pivotal elements of the Butler court\u27s analysis will be discussed in light of American decisions. The authors propose that a Butler analysis offers a more honest and balanced approach to the pornography issue, and that such an approach would be feasible within the parameters of the First Amendment in the United States

R. v. Butler: Recognizing the Expressive Value and the Harm in Pornography

The recent Canadian Supreme Court decision of R. v. Butler recognizes and addresses the harmful anti-social attitudes and behaviors towards women which are perpetuated by misogynistic, violent pornography. Meanwhile, American courts continue to grapple with their traditional obscenity standard. This comment presents an overview of the American approach to regulating and categorizing pornography, and explores the obstacles this approach creates for addressing the issues of harm to women. The pivotal elements of the Butler court\u27s analysis will be discussed in light of American decisions. The authors propose that a Butler analysis offers a more honest and balanced approach to the pornography issue, and that such an approach would be feasible within the parameters of the First Amendment in the United States

Development of advanced silicon solar cells for Space Station Freedom

This report describes the development of large area high efficiency wrapthrough solar cells for Space Station Freedom. The goal of this contract was the development and fabrication of 8 x 8 cm coplanar back contact solar cells with a minimum output of 1.039 watts/cell. The first task in this program was a modeling study to determine the optimum configuration of the cell and to study the effects of surface passivation, substrate resistivity, and back surface field on the BOL and EOL performance. In addition, the optical stack, including the cell cover, AR coatings, and Kapton blanket, was modeled to optimize 'on orbit' operation. The second phase was a manufacturing development phase to develop high volume manufacturing processes for the reliable production of low recombination velocity boron back surface fields, techniques to produce smooth, low leakage wrapthrough holes, passivation, photoresist application methods, and metallization schemes. The final portion of this program was a pilot production phase. Seven hundred solar cells were delivered in this phase. At the end of the program, cells with average efficiencies over 13 percent were being produced with power output in excess of 1.139 watts/cell, thus substantially exceeding the program goal

Production status of GaAs/Ge solar cells and panels

GaAs/Ge solar cells with lot average efficiencies in excess of 18 percent were produced by MOCVD growth techniques. A description of the cell, its performance and the production facility are discussed. Production GaAs/Ge cells of this type were recently assembled into circuits and bonded to aluminum honeycomb panels to be used as the solar array for the British UOSAT-F program

Progress toward the development of dual junction GaAs/Ge solar cells

Large area GaAs/Ge cells offer substantial promise for increasing the power output from existing silicon solar array designs and for providing an enabled technology for missions hitherto impossible using silicon. Single junction GaAs/Ge cells offer substantial advantages in both size, weight, and cost compared to GaAs cells but the efficiency is limited to approximately 19.2 to 20 percent AMO. The thermal absorptance of GaAs/Ge cells is also worse than GaAs/GaAs cells (0.88 vs 0.81 typ.) due to the absorption in the Ge substrate. On the other hand dual junction GaAs/Ge cells offer efficiencies up to ultimately 24 percent AMO in sizes up to 8 x 8 cm but there are still technological issues remaining to achieve current matching in the GaAs and Ge cells. This can be achieved through tuned antireflection (AR) coatings, improved quality of the GaAs growth, improved quality Ge wafers and the use of a Back Surface Field (BSF)/Back Surface Reflector (BSR) in the Ge cell. Although the temperature coefficients of efficiency and voltage are higher for dual junction GaAs/Ge cells, it has been shown elsewhere that for typical 28 C cell efficiencies of 22 percent (dual junction) vs 18.5 percent (single junction) there is a positive power tradeoff up to temperatures as high as 120 C. Due to the potential ease of fabrication of GaAs/Ge dual junction cells there is likely to be only a small cost differential compared to single junction cells

Turning Traitor: Shifting Loyalties in Procopius’ Gothic Wars

Η αφήγηση του ιστοριογράφου Προκoπίου για τον πόλεμο εναντίον των Γότθων στην Ιταλία περιέχει πολλές περιπτώσεις Γότθων, Ιταλών και Ανατολικών Ρωμαίων που αλλάζουν παρατάξεις κατά τη διάρκεια της μακράς σύγκρουσης. Η συστηματική εξέταση του θέματος δείχνει ότι ο Προκόπιος γενικά αντιμετώπιζε με συγκατάβαση τους στρατιώτες που λιποτακτούσαν, στάση, που αντικατοπτρίζει τις ευρύτερες μεσογειακές αντιλήψεις του 6ου αιώνα. Τί μπορούν να μας διδάξουν τα παραδείγματα των «προδοτικών» συμπεριφορών σχετικά με τη διαφωνία στην εποχή του Ιουστινιανού; Παρόμοιες και άλλες πράξεις διαφωνίας από στρατιώτες υποδηλώνουν ότι μονάδες του στρατού του Ιουστινιανού –τουλάχιστον κατά τη διάρκεια του δυτικού πολέμου– είχαν κάποιο επίπεδο ελευθερίας του λόγου και της δράσης, που μερικές φορές τους επέτρεπε να υπαγορεύουν όρους είτε στον διοικητή τους είτε στην κεντρική κυβέρνηση στην Κωνσταντινούπολη. Με τον ίδιο τρόπο και η γοτθική αντίσταση στην Ιταλία, μπορεί να ερμηνευθεί ως μια πράξη μη συμμόρφωσης προς την πολιτική που τους αντιμετώπιζε ως βαρβάρους, χωρίς νόμιμη αξίωση για την Ιταλία

Metrical properties of convex sets

There have been many contributions of work in different fields of convexity giving various metrical properties of convex sets. In this thesis we shall consider some further ideas which seem interesting to study. A standard way of tackling certain types of problems is to prove the existence of an 'extremal' convex set with respect to the property in consideration and by a series of arguments determine its construction. Generally speaking the extremal set turns out to be regular in some sense with a correspondingly easy geometry. In Chapters 1 and 2 we shall concern ourselves entirely with polytopes and we shall give some results on the metric properties of their faces. Following these results, we shall in Chapter 3 consider some continuity properties of the more general class of cell-complexes. In Chapters 4, 5 and 6, we shall confine ourselves to the plane. In Chapter 4, we shall consider sets which incertain senses correspond to the sets of constant width. This leads us in Chapter 5 to give some results concerning the minimal widths of triangles circumscribing convex sets. Finally, in Chapter 6 we consider the areas of certain subsets of a convex set which are determined by partitions of that set by three concurrent lines. Papers which are relevant to the field of study in a particular chapter are mentioned briefly in an introduction to that chapter.<p