Energy requirement for the production of silicon solar arrays

An assessment of potential changes and alternative technologies which could impact the photovoltaic manufacturing process is presented. Topics discussed include: a multiple wire saw, ribbon growth techniques, silicon casting, and a computer model for a large-scale solar power plant. Emphasis is placed on reducing the energy demands of the manufacturing process

Energy requirement for the production of silicon solar arrays

Photovoltaics is subject of an extensive technology assessment in terms of its net energy potential as an alternate energy source. Reduction of quartzite pebbles, refinement, crystal growth, cell processing and panel building are evaluated for energy expenditure compared to direct, indirect, and overhead energies

Nanoscale Defect Formation on InP(111) Surfaces after MeV Sb Implantation

We have studied the surface modifications as well as the surface roughness of the InP(111) surfaces after 1.5 MeV Sb ion implantations. Scanning Probe Microscope (SPM) has been utilized to investigate the ion implanted InP(111) surfaces. We observe the formation of nanoscale defect structures on the InP surface. The density, height and size of the nanostructures have been investigated here as a function of ion fluence. The rms surface roughness, of the ion implanted InP surfaces, demonstrates two varied behaviors as a function of Sb ion fluence. Initially, the roughness increases with increasing fluence. However, after a critical fluence the roughness decreases with increasing fluence. We have further applied the technique of Raman scattering to investigate the implantation induced modifications and disorder in InP. Raman Scattering results demonstrate that at the critical fluence, where the decrease in surface roughness occurs, InP lattice becomes amorphous.Comment: 18 pages, 9 figure

Uppåkra arkeologiska center

Uppåkra is the name of a rich archaeological site located in Skåne, southern Sweden. The site, sitting on top of a hill in an otherwise plain landscape, was once the center of a what is believed to be the biggest iron age settlement in Scandinavia. Due to lack of funding, little knowledge and interest from outside the region, only a minor part of the site has been excavated so far. Today, Uppåkra gives a modest impression, consisting of a rural village and a church surrounded by fields of crops. For anybody passing by there is nothing that tells them that this once was a grand society, very different from the small village of today. The task for the diploma project is to design a visitor center to Uppåkra with the purpose of mediating the history of the site and provide facilites for archaeologists to conduct research. The project adresses the paradox of building upon an archeological site: the visitors center is needed to mediate the site, but building on top of the archaeological findings could potentially destroy them. The proposed visitor center begins on a landscape level, where pathways acts as thresholds, mediating the existance of the site. On a building level, the visitor center is divided in two parts: an exisiting barn is transformed to accomodate the permanent parts of the program, while an unclimatized pavillion interacts with the continuing excavations of the site. Using a flexible constructive system, the pavillion may expand as the collections of objects grow, retract if a place occupied by the building needs to be excavated, and respond to any new findings that may change the perception of the site. The intention is to fullfil the purpose of a typical visitor center: a building belonging to a place that has a greater importance than the building itself.submittedVersio

Ladies, Whores, and Holy Women: A Sourcebook in Courtly, Religious, and Urban Cultures of Late Medieval Germany

This sourcebook presents editions and translations of seven fourteenth- and fifteenth-century texts that advance our understanding of gender, sexuality, and class in the late medieval German-speaking world. Three of the translated texts are fiction. Additionally, there is a religious treatise, a religious legend, an inventory of books, and a legal document. While each of these texts is instructive in and of itself, they gain in complexity when brought into dialogue with one another.https://scholarworks.wmich.edu/mip_teamsmgt/1004/thumbnail.jp