Next generation interconnective laser patterning of CIGS thin film modules

Laser patterning of thin film solar cells has proven technically feasible for all layers but still remains a challenging topic for research and development. We present a method where P2 laser patterning of CIGS thin film solar modules is performed after deposition of the ZnO:Al layer, as opposed to the current state-of-the-art where patterning is performed before the ZnO:Al layer is deposited. This method takes full advantage of the potential of laser processing and works by creating an interconnecting scribe line that “welds” the ZnO:Al and CIGS layers into an electrical contact. In this work we present experimental results of this process on five different sets of CIGS with slightly varying thickness and Cu content. While optimization of the process with respect to the various layers has not been performed, the initial results for CIGS thin film modules show working experimental modules in each set. The best experimental module has a fill factor of 71% and its performance is within the standard deviation of mechanically patterned references. An experimental submodule of 30×30 cm² size with 10% efficiency was manufactured.     

Zoning and the Nouveau Poor

The nouveau poor, women heading households, who have experienced a dramatic shift from middle income to low income status due to divorce, widowhood, or abandonment, and who own their own homes in America's suburban and small towns constitute a demographic group whose housing opportunities are limited by certain restrictive zoning practices.

Outmoded regulations, such as those with restrictive definitions of family and age-restrictive zoning regulations and covenants, deny these families the opportunity to enter into housesharing arrangements or to divide their homes into principal and accessory units. Because of these policies, nouveau poor families may find that they cannot continue to live in the communities that they had sought out as ideal places for raising their children. Although restrictive zoning regulations have generally been upheld by the courts, they have at times been successfully attacked. An understanding of the court decisions and their public policy implications will provide guidance for land use officials so they can respond to the housing needs of the nouveau poor.     

Deceleration Through the Imprint: Photo/graphic interactions in contemporary art

Art historian David Joselit has recently argued that the task of art today is resist “the allure” of information’s “transparency”. This places a specific emphasis on photographic images. The ease of their production and ubiquity of use — as a crucial element in economic, social and cultural acceleration processes tied to information — has increased the implicit transparency that has arguably been one of photography’s most prominent attributes. The article suggests that printmaking can provide valuable procedural, aesthetic and conceptual means in the questioning of the photographic image’s assumed transparency that thereby contribute to the image’s criticality. Drawing on the concept of the “imprint” — as developed by the French art historian Georges Didi-Huberman in a still untranslated study — the article undertakes an analysis of a specific mode of contemporary printmaking, namely the woodcut. It is proposed that the distinctive material methods developed by the two chosen artists, Brook Andrew and Christiane Baumgartner, present a unique manifestation of the imprint that results in a process of slowing down the viewer’s apperception. Concurrently — and closely related to the artists’ thematic concerns — they can generate an enquiry of photography’s transparency and thus enhance its socio-cultural potential of critique.     

Authentication of organic and conventional eggs by carotenoid profiling

Organic production benefits from fair competition and sustained consumer confidence. The latter can only be assured by paper trailing and verification assessments. Traditional analytical strategies for guaranteeing quality and uncovering adulteration have relied on the determination of the amount of a marker compound or compounds in a material and a subsequent comparison of the value(s) obtained with those established for equivalent material. Since it is unlikely to find a unique marker that allows discrimination between organic and conventional produce, selective fingerprinting (profiling) combined with chemometrics is a more promising approach. In this study, carotenoid High Performance Liquid Chromatography–Diode Array Detection profiling combined with k-nearest neighbour classification chemometrics was used to predict the production system (organic vs. non-organic) of chicken eggs. A proof-of-concept set (training set for the model) was composed of eggs from 24 organic farms, 12 free range, and 12 barn farms in the Netherlands. The identities of organic, free range, and barn eggs were predicted with success rates of 100%, 100%, and 84%, respectively. The identity of eggs determined using an additional market test set with eggs from 12 organic, 12 free range, and 12 barn farms originating from the Netherlands and New Zealand resulted in correct classifications for 35 of the 36 samples. The results of this study indicate that this fingerprint approach is a promising tool for analytical verification of the production system of organic eggs.