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

Aetiology of juvenile-onset diabetes mellitus

MD ThesisIn Britain the incidence of juvenile-onset diabetes in children appears to be increasing. The incidence in Northamptonshire in 1949 was 1: 7000 children, aged 0- 15 years and a survey of diabetic children of similar age in Sunderland during a ten year period, 1967-76, revealed an incidence of 1: 400. The Sunderland survey comprised ninety-five diabetic children who were divided into three age groups 0-4 years, 5-9 years and 10 - 14 years. Overall more boys than girls develop diabetes, particularly in the younger 0-4 year group but girls increase in number and almost equal boys in the two older groups 5-9 years and 10 - 14 years. The peak age of onset is eight and eleven years, consisting mainly of girls; however, boys predominate at twelve years of age. These peak age ranges related to sex could indicate that the underlying provoking factor in the aetiology of diabetes at these ages may be adrenarche or puberty. Environmental factors also appear to play a role in the aetiology of juvenile-onset diabetes as more diabetic children present with their illness in the winter six months, October to March. This winter onset tendency was more significant in the older children (10 - 15 years), and spatial clustering of the disease in Sunderland children occurred, tending to confirm environmental influences such as infection in the community. Clustering of cases was also related to the highter social class areas of the town, consequently 80% of the diabetic children came from social groups I, II and III. Only 7% of the diabetic children had a first degree insulin dependent diabetic relative compared to the national figure of 11%. A study of the extended family history revealed that almost half the Sunderland diabetic girls and one-third of the boys had a relative with insulin dependent diabetes. The diabetic child with the phenotypes H. L. A. - B8, BW15 and BW18 had a very significant tendency to an extended family history. An analysis of the H. L. A. phenotype showed that 75% of the diabetic children had H. L. A. - B8, BW15 or BW18 phenotype. 53% had H. L. A. - B8 compared to 24% controls. This B8 phenotype accounted for half the children in each of the three age groups. The majority of boys with H. L. A. - B8 presented in the winter six months, whilst girls with this phenotype presented evenly throughout the year. This could suggest that the provoking factor in the aetiology of diabetes in boys with H. L. A. - B8 could be an infection. The H. L. A. - B40 phenotype, not previously associated with a diabetogenic tendency, appears to fall into a similar category to boys with H. L. A. - B8. The height of the diabetic children at the onset of the illness was compared to the height of local children and also to the national centile values. The mean height of the local children (25th centile) was found to be significantly below the national 50th centile. The Sunderland diabetic children were equally distributed about the national 50th centile value and consequently were significantly taller than the local children. Although 80% of the diabetic children were above the local mean height, the diabetogenic phenotypes H. L. A. - B8, BW15 and BW18 were not associated with the very tall diabetic child. Most of the diabetic boys and girls above the 75th height centile had H. L. A. - B7 or B12 phenotypes. If H. L. A. - B8 was combined with either of these two phenotypes the children were shorter in stature. It is possible that the provoking factor in the development of diabetes in boys with H. L. A. - B8 is an infection, whilst diabetes in girls with H. L. A. - B8, BW15 or BW18 appears to be related to puberty or adrenarche. Children with H. L. A. - B7 or B12 may be associated with a different endocrine imbalance producing excessive tallness prior to diabetes becoming evident