Analysis Techniques of Polymeric Encapsulant Materials for Photovoltaic Modules: Situation and Perspectives

AbstractThe properties of the encapsulant are critical to the long-term performance of photovoltaic (PV) modules under the influence of sunlight including UV, elevated temperature, humidity and diffusion of oxygen. Encapsulation process represents about 40% of the whole PV module cost. The introduction of new non-EVA encapsulant material type ″Low-Cost, High-Performance″ should provide a solution to outdoor yellowing degradation problems. The emerging encapsulant materials exhibit a good compatibility with emerging PV solar cells for long term durability. This new generation of encapsulant materials has the advantage to improve the PV module performances and long term durability for specific climate like desert regions. This scientific contribution presents an overview of the different encapsulant materials currently on the market, the general requirements of the emerging encapsulant materials and characterizations techniques for degradation, diagnostic and reliability lifetime estimation in the framework of Algerian renewable energy strategy

A new method to predict optimum cure time of rubber compound using dynamic mechanical analysis

The degree of vulcanization of a rubber compound has a big influence on the properties of the final product. Therefore, precisely defining the curing process including optimum cure time is important to ensure the production of final products having high performance. Typically, vulcanization is represented using vulcanization curves. The main types of equipment used for producing vulcanization curves are the oscillating disc rheometer (ODR) and the moving die rheometer (MDR). These can be used to plot graphs of torque versus time at a constant temperature to show how cure is proceeding. Based on the results obtained, optimum cure time (t₉₀) is calculated as the time required for the torque to reach 90% of the maximum achievable torque. In this study, the use of Dynamic Mechanical Analysis (DMA) for assessment of t₉₀ was assessed. DMA was carried out using shear mode isothermal tests to measure the changes in material properties caused by vulcanization. The results revealed that the shear storage modulus (G′), shear loss modulus (G′′), and tan δ all reflect the vulcanization process, however, tan δ gave the best representation of level of vulcanization. Indeed, the curve of tan δ was able to be used to derive the t₉₀ for rubber compounds and showed good agreement with the results from an MDR

Fourier Spektroskopische Untersuchungen im Mittleren und Fernen Infrarotbereich an Co 60 bestrahlten und thermisch belasteten ultrahochmolekularen Polyethylen Proben

Fourier Spektroskopische Untersuchungen von hochmolekularem Polyethylen HMW PE und ultrahochmolekularem Polyethylen UHMW PE im Mittleren und Fernen Infrarotbereich können Veränderungen der molekularen Strukturen nachweisen, die durch Co60 amp; 947; Strahlung und Rekristallisationsprozesse initiiert werden. UHMW PE und HMW PE sind im gewählten IR Bereich unterscheidbar. Die integrale Absorption der B1u Gitterschwingungen im Fernen Infrarotbereich THz Bereich ermöglichen die quantitative Beschreibung des Kristallinitätsgrades und dessen Abbau. Die Bildung ungesättigter Vinylengruppen und der Abbau ungesättigter Methylengruppen können im Mittleren Infrarotbereich nachgewiesen werde

THz and mid IR Fourier Transform Spectroscopy on Polyethylene irradiated with gamma Co60 radiation

THz and mid IR spectroscopy of high molecular PE HMW and ultra high molecular PE UHMW reveals modifications of the molecular structure induced by amp; 947; Co60 radiation. UHMW PE and HMW PE can be distinguished. The integral absorption in the B1u THz region can quantitatively describe the amorphization of crystallinity. The formation of trans vinylene unsaturations and the decay of vinyl can be followed by mid IR spectroscop

ADDITIVE MANUFACTURING OF PERSONALIZED WETSUITS

Additive manufacturing (AM) provides opportunities to customize parts with precise control of geometry and materials. An application for the Navy is the fabrication of user-tailored wetsuits with superior fit, as well as enhanced thermal and mechanical properties required for dives at cold temperatures and high pressures. The goal of this project is to investigate AM for the fabrication of wetsuit parts. A 3D scanner was used to generate a digital model of a hand, which was modified with a modeling tool to form a glove and sliced for printing. The glove was 3D printed using fused filament fabrication with multiple methods and materials, including thermoplastic polyurethane elastomer (TPU), polyvinyl alcohol polymer (PVA), and polylactic acid (PLA). PLA was initially used to determine appropriate settings for the other materials. A fully TPU-printed glove most closely resembled a wetsuit with an excellent fit. TPU printed at 100% infill proved to be stiffer than neoprene, which might be advantageous for higher external pressures. Alternatively, a water-soluble PVA part was printed to use as a scaffold and a neoprene gel was applied to the outside, which left a thin shell of neoprene upon dissolution of PVA in water. This shell had the flexibility of a traditional wetsuit, but lacked thickness, which would require multiple applications of the gel. The results suggest a combination of these approaches can be used for producing next-generation personalized wetsuits for the Navy.Ensign, United States NavyApproved for public release. Distribution is unlimited

Musical and artistic use of new technologies exemplifying the composers Ludger Brümmer, Paulo Ferreira Lopes and Kiyoshi Furukawa

Vom musikalisch-künstlerischen Umgang mit neuen Technologien am Beispiel der Komponisten Ludger Brümmer, Paulo Ferreira Lopes und Kiyoshi Furuka-wa Das Ziel der Dissertation bestand darin, Erkenntnisse darüber zu erhalten, a) wie Komponisten heute elektronische und digitale Techniken verwenden, b) welche Kunstauffassung hinter dieser Art zu komponieren steckt und c) auf welche Weise wir Merkmale von elektronischer Komposition bestimmen können. Dazu wurden die Komponisten Ludger Brümmer, Paulo Ferreira Lopes und Kiyoshi Furukawa in den Blick genommen. Ausgehend von ihren verbalen Äußerungen wur-de untersucht, wie sich ihre jeweilige Musikästhetik in ihrem kompositorischen Um-gang mit neuen Technologien widerspiegelt. Der Umgang mit neuen Technologien ist bei dem Komponisten Ludger Brümmer ge-prägt von dem Bedürfnis, Computermusik als neue musikalische Gattung zu etablieren. Er entwickelt Klangsynthese-Techniken, die an physikalischen Gesetzen orientiert sind. In seiner Komposition ->Thrill<- (1998) z.B. zeigt sich, wie er einzelne Klangspuren mit algorithmischen Strukturen gestaltet und eine Verknüpfung von Bild und Ton durch die Anwendung gleicher Synthese-Techniken sucht. Paulo Ferreira Lopes widmet sich der Live-Elektronik und der Erforschung von Inter-faces. Sein Fortschrittsdenken zeigt sich z.B. in der These, dass sich die Musik auf-grund der Nähe zwischen Kunst und Wissenschaft in einem Epochenwechsel befin-det. Er bezweckt eine Irritation der Wahrnehmung beim Rezipienten: doN für Trom-pete und Live-Elektronik (2000) z.B. changiert zwischen natürlichen und künstlichen Trompetendämpfern und weist u.a. Bezüge zur Medienontologie von Marshall McLu-han auf. Kiyoshi Furukawas Anwendung neuer Technologien steht unter dem Einfluss z.B. der Spielphilosophien und Kommunikationstheorien von Jean-François Lyotard und Vi-lém Flusser. Sie prägen die Ästhetik seiner live-elektronischen Performances und seines Musiktheaters Den ungeborenen Göttern (1997). In der äußeren Form der CD-ROM-Installation Small Fish (1999) findet seine Kunstanschauung eine adäquate äußere Form. Die Ergebnisse der Untersuchung legen nahe, dass für die Beschreibung von elekt-ronischen Kompositionen die Unterscheidung zwischen drei Ebenen sinnvoll ist: 1. Innere Formen, z.B. Live-Elektronik, elektronische Klangsynthese, Raum-klangbewegungen. 2. Äußere Aufführungsformen, z.B. Konzert, Musiktheater, Lautsprecherpräsen-tation oder Installation. 3. Kunstanschauung, die den ästhetischen Hintergrund für das jeweilige Werk bildet und die innere wie die äußere Form prägt. Mit dieser Unterscheidung kann die Bewertung von elektronischer Komposition als musikalische Gattung sinnvoll sein und schafft eine Grundlage für Diskussionen und Reflexionen.Musical and Artistic Use of New Technologies Exemplifying the Composers Ludger Brümmer, Paulo Ferreira Lopes and Kiyoshi Furukawa The dissertation aimed to receive knowledge about a) how composers currently use electronic and digital technology, b) which aesthetic these kinds of compositions pre-sent and c) in which way we can specify characteristics of electronic composition. It focussed on the composers Ludger Brümmer, Paulo Ferreira Lopes and Kiyoshi Furukawa and analyzed - starting from their verbal comments - how their aesthetics are reflected in their compositions. The composer Ludger Brümmer's use of new technologies is based on his request to establish computer music as a new musical genre. He develops techniques of sound synthesis depending on physical laws. In his composition ->Thrill<- (1998) e.g. he configures the tracks using algorithmic structures and seeks for a linking between visuals and sounds applying the same techniques. Paulo Ferreira Lopes works on live-electronic music and explores musical interfaces. His believe in progress is manifested within his thesis that music is currently in change of era. He aims to irritate the audiences' perception: doN for trumpet and live-electronic (2000) e.g. alternates between natural and artificial trumpet mutes and shows references to Marshall McLuhan's media theory. Kiyoshi Furukawa's use of new technologies is influenced by the philosophy of games and communication theories of Jean-François Lyotard, Vilém Flusser and others. They affect the aesthetics of his live-electronic performances and of his musi-cal scene To the Unborn Gods (1997). With the CD-ROM-installation Small Fish (1999) his concept of art found an adequate form of appearance. The results of this investigation demonstrate that for describing electronic composi-tion it is useful to distinguish between three aspects: 1. Internal form, e.g. live-electronic, sound synthesis, spatial movements 2. Appearance, e.g. concert, opera, tape music, installation 3. Aesthetics constituting the background of the composition and influencing its internal form and appearance. Using this distinction electronic composition can be considered a musical genre in order to be discussed and reflected

Anlagestrategie Behavioral Finance : die Bedeutung verhaltensorientierter Anlagestrategien in der amerikanischen und deutschen Fondsindustrie

This dissertation investigates empirically the degree of implementation of Behavioral Finance theory in the investment fund industry. In a first step the author identifies the most prominent Behavioral Finance based investment strategies according to academic literature. Then, based on regression analysis, the author examines the extent to which German and U.S. mutual fund managers apply Behavioral Finance based investment strategies, and how great the resulting success is. The findings show that, while their degree of implementation remains low particularly in Germany, Behavioral Finance based investment strategies do, on the whole, have a positive impact on fund performance. The established financial theory builds on efficient markets and rational behavior of market participants. It further postulates that stock prices immediately as well as comprehensively incorporate all available information, and that active asset management cannot sustainably generate positive excess returns. However, extensive empirical research shows that stock prices do not always fully adjust to new relevant information. The relatively recent Behavioral Finance theory addresses in particular the emergence of systematic distortions in asset prices, driven by emotions and cognitive biases. In contrast to the established view, Behavioral Finance theory builds on limited arbitrage and market participants that do not always act rationally. In particular over- and underreaction can cause that asset prices deviate from the fundamentally justified levels in a predictable manner. Hence, active investment strategies that use the insights of Behavioral Finance and exploit systematic market distortions should generate significant excess returns. Measured by the number of pertinent research projects the most important behavioral investment strategies are the momentum, contrarian, and earnings surprise strategies, whose justification is usually directly and almost exclusively associated with the bounded rationality of human decision behavior. On the other hand, the author also includes in the investigations the classic style strategies size and value, even though there is controversy in the pertinent literature as to whether the profitability of these strategies might not also be explicable as justified risk premium in an efficient market setting with rational market participants. The author calculates historical returns for each strategy over the test period 1/1990 to 12/2005. The results show that several strategies generate significant excess returns if applied to the US and German stock market. However, the volatility of strategy returns over time points out that the underlying market inefficiencies are by far not as systematic and predictable as the Behavioral Finance theory suggests. Applying multiple linear regression analysis the author measures the degree of implementation of different sets of behavioral and style strategies within the US and German fund industry. The sample of investigated funds comprises in total 2,778 US American and 111 German actively managed equity funds with a local investment focus. The empirical analysis shows the following results: A small group of US American funds, so called Behavioral Finance funds, explicitly refers to Behavioral Finance in the external communication. As a matter of fact some of these funds apply behavioral investment strategies and generate positive excess returns. Prominent examples are the Fuller & Thaler funds that are grounded in the academic field of Behavioral Finance. Although behavioral strategies represent only a fraction of the overall investment strategy of these funds, results support a positive correlation between degree of implementation of the strategies and fund performance. Thus, applying behavioral as well as style strategies pays out for the managers of (and investors in) selective Behavioral Finance funds. Whereas also the results for the other US funds indicate a certain degree of implementation of style strategies and selective use of behavioral strategies, the German funds analyzed here rarely apply these strategies. The latter rather focus on replicating the overall market index and do that with very limited success. Two possible explanations come to mind that could explain the yet limited degree of implementation of behavioral and style strategies: i) transaction costs that might erase the excess return of a strategy when it comes to practical implementation, and ii) the attempt of fund managers to avoid dissonance that would emerge from a possible negative deviation from market return. Complementary analysis shows that excess returns of selective investment strategies remain significant when accounting for transaction costs. The possibility of dissonance avoidance is not assessed in further detail, but could mark a starting point for future research in this field