Artificial Photosynthesis

One-dimensional channel materials, such as zeolites and mesoporous silicas, are very attractive hosts for the preparation and investigation of hierarchically organized structures, presenting a successive ordering from the molecular up to macroscopic scale. The focus of this article is on artificial photonic antenna systems and on photocatalytically active layers that have been built by incorporating organic dyes, complexes, metal cations and clusters into 1-D nanochannel materials. We show that zeolite L as a host material allows for the design and preparation of a large variety of highly organized host-guest systems. The combination of a tuneable host morphology and the possibility of obtaining highly organized molecular patterns of guests leads to a variety of potential optical and photoelectronic applications. Strongly absorbing systems exhibiting efficient FRET along the c-axis of the zeolite crystals are accessible by sequential inclusion of multiple types of dyes. These new light-harvesting materials offer unique possibilities as building blocks for solar-energy conversion devices. A complementary approach consists in integrating photochemically active substances into zeolite monolayers coated on an electrode and taking advantage of intrazeolite processes for designing a reversible electrode for photocatalytic water oxidation. The photoelectrochemical water splitting capability of systems based on Ag+/AgCl/Agn-zeolite photoanodes are discusse

Exhibition and Cognition: Gottfried Semper's Strolls in the Crystal Palace

This doctoral thesis examines the theoretical and practical work of the German architect Gottfried Semper during the Great Exhibition of 1851 and discusses how his work came to be influenced by imperialism, colonialism and capitalism. The celebrated event in the Crystal Palace in Hyde Park coincided with Semper’s growing interest in the four essential crafts (weaving, pottery, carpentry, masonry) that he believed formed the basis from which architecture had originated. To this end, the Great Exhibition furnished Semper’s theoretical endeavours with a plethora of material objects he could study from all around the world. The thesis first analyses and partly reconstructs Semper’s own designs for some national sections within the Crystal Palace. It then follows the walks through the exhibition that Semper undertook with his friend, Lothar Bucher, as a means to look at the ethnographic material they encountered. Behind all of Semper’s reflections upon the displayed objects was a concept of cultural development rooted in German Idealist thought as produced by thinkers such as Kant and Hegel. However, Semper’s observations also instigated a profound critique of contemporary modes of production in industrialised societies. The thesis therefore shows how Semper redirects anthropological ideas about object fetishism in earlier societies towards an analysis of the world of capitalist commodities and their representations. In this regard, the thesis sketches out a shift in Semper’s thought from a critique of religion to a critique of capitalism, with similarities to another German émigré in London at the time, Karl Marx. Yet, in the end Semper refrained from Marxist theory and instead carried out investigations into the production of artistic objects. Accordingly, the thesis discusses Semper’s plan for an ideal museum which he hoped could overcome the crisis of production and representation within capitalism by looking for universal principles of design

Performance analysis under finite load and improvements for multirate 802.11

Automatic rate adaptation in CSMA/CA wireless networks may cause drastic throughput degradation for high speed bit rate stations (STAs). The CSMA/CA medium access method guarantees equal long-term channel access probability to all hosts when they are saturated. In previous work it has been shown that the saturation throughput of any STA is limited by the saturation throughput of the STA with the lowest bit rate in the same infrastructure. In order to overcome this problem, we ¯rst introduce in this paper a new model for ¯nite load sources with multirate capabilities. We use our model to investigate the throughput degradation outside and inside the saturation regime. We de¯ne a new fairness index based on the channel occupation time to have more suitable de¯nition of fairness in multirate environments. Further, we propose two simple but powerful mechanisms to partly bypass the observed decline in performance and meet the proposed fairness. Finally, we use our model for ¯nite load sources to evaluate our proposed mechanisms in terms of total throughput and MAC layer delay for various network con¯gurations

PENGGUNAAN GOOGLE CLASSROOM DALAM PEMBELAJARAN TEMATIK DENGAN PENDEKATAN SAINTIFIK DI SEKOLAH DASAR

Abstract This study to describe the planning, implementation, and students responses to the use of google classroom in thematic learning with scientific approach in elementary schools. This study used qualitative approach with descriptive methods which was conducted at Public Elementary School 20 SKPI SP 5 Nobal. The subjects in this study were the principal, grade VI teachers, and grade VI students. Data collection was carried out using interview sheets, observation sheet, and documentation. Based on the results of research, it shows that grade VI teachers in making thematic lesson plans with a scientific approach using google classroom are in accordance with Permendikbud Annex IV Number 81 A of 2013. The implementation of learning activities have implemented the scientific approach activities. Student responses to thematic learning with a scientific approach using google classroom which is carried out in class VI Elementary School 20 SKPI SP 5 Nobal Sungai Tebelian Sintang are generally good enough. This can be seen from the results of the interview which showed that the average value of 4 indicators proposed was 96.52%. Keywords: Elementary Schools, Google Classroom, Scientific Approach, Thematic Learnin