Design of fibre reinforced PV concepts for building integrated applications

Fibre reinforced polymers present an interesting encapsulation medium for PV-modules. Glass fibres can provide increased strength and stiffness to thin polymer layers overcoming the brittleness and limited deformability of glass-panes. Glass fibre reinforced polymers allows for transparency over a broad range of the solar spectrum while the material properties and integral production processes create possibilities for novel product concepts with embedded PV technology. To explore such possibilities, innovative design methods were used to design novel PV product concepts for applications in the build environment.\ud In our paper three conceptual designs are presented; (1) a thin film module with an adjoining interconnection system functioning as structural element for geodetic roofing structures, (2) a PV lamella with single-axis tracking utilizing a linear concentration effect caused by the geometry of the product and the materials applied, and (3) a prepreg PV-material which allows for easy shaping during the production of PV modules with complex geometries. Each concept employs a specific PV technology and demonstrates a possible application aimed at a specific market. In this way we show the potential of integration of PV technology in fibre reinforced composites. The paper will be illustrated by concept renderings

Hubungan Migrasi Perlekatan Otot Pada Tulang Panjang Dengan Perubahan Panjang Tulang Dan Volume Otot Pada Perlakuan Hiperaktivitas Selama Pertumbuhan

This study was aimed to recognize the ccorrelation between migration of muscle attachment on long bone and the change of bone length and mucle volume in a hyperactivity treatment during bone growth. A number of 150 male rats (Rattus norvegicus) were used as experimental animal. Randomly, the experimental animals were divided into three groups (1) the first group consisted of 30 rats, were used to examine the anatomical structure of the rats, and the accuracy of placing metal pins of muscles and of the bone shaft, (2) the control group (60 rats) and (3) the hyperactivity group (60 rats) were given increased muscular activity by physical exercise in every groups. Metal pins were implanted in the middle of the femoral and the tibial bone shaft, and 30 rats (the first group) were directly sacrificed. Every 2 months and 6 months following treatment, the hyperactivity and the control group were sacrificed. Five muscles which were attached on the femur and on the tibia were cut and their volumes, absolute distance and proportional distance of their attachment to the metal pins, and to the length of the bone were measured. It was found that in the hyperactivity rats, a change of bone length was detected, whereas none in the control group. The change of the long bone was significantly correlated proportionally with the migration of the attachment of the muscle. In the treated group, muscle volume differed compared to that in the control group. However, the difference of the muscle volume was not correlated with the migration of the muscle attachment during bone growth. In conclusion, there was a convincing correlation between the migration of the muscle attachment and the change of bone length in hyperactivity group during bones growth

Hubungan Migrasi Perlekatan Otot Pada Tulang Panjang Dengan Perubahan Panjang Tulang Dan Volume Otot Pada Perlakuan Bipedal Selama Pertumbuhan

Dalam penelitian ini diselidiki hubungan antara migrasi perlekatan otot pada tulang panjang dengan penambahan beban dengan perlakuan bipedal selama pertumbuhan. Sebagai hewan percobaandipakai 150 ekor tikus jantan (Rattus norvegicus) strain Lembaga Makanan Rakyat Departemen Kesehatan Republik Indonesia, berumur 6 minggu dan dengan berat rata-rata 70 gr. Perlakuan dibeikan selama 6 bulan. Secara randomisasi hewan percobaan dibagi atas beberapa kelompok, yaitu kelompok Wo pemasangan kawat penunjuk pada corpus tulang, kelompok kontrol sebanyak 60 ekor tikus, sebagai kelompok pembanding, kelompok bipedal sebanyak 60 ekor tikus dan mendapat penambahan berat badan secara bipedal pada tulang. Pada semua kelompok dipasang kawat penunjuk pada pertengahan corpus femoris dan corpus tibiae. Selama perlakuan, hewan percobaan dibiarkan hidup bebas dalam kandang selama 2 sampai 6 bulan, tikus diberi makan dan minum ad libitum. Pada tiap-tiap kelompok, 30 ekor tikus dikorbankan pada waktu 2 bulan dan 6 bulan sesudah perlakuan. M. Gluteus maximus, M. Pectineus, M. adductor brevis, M. addductor magnus dan M. aastrocnemius yang melekat pada femur, dan M. rectus femoris, M.semimembranosus, M.gracilis, M.semitendinosus dan M.tibialis anterior yang melekat pada tibia dipotong dan diukur volumenya serta diukur jarak perlekatannya secara absolut dan secara proporsional terhadap jarak dari kawat penunjuk ke ujung tulang. Femur bagian proximal, femur badian distal dan tibia bagian proximal diukur panjangnya terhadap kawat penunjuk. Dicari korelasi antara selisih panjang tulang dan volume otot antara perlakuan 6 bulan dan 2 bulan dengan selisih jarak absolut (migrasi absolut) dan selisih jarak proporsional (migrasi proporsional) perlekatan otot antara perlakuan 6 bulan dan 2 bulan. Hasil yang didapat dari penelitian ini memberikan gambaran bahwa perlakuan bipedal ada korelasi antara migrasi perlekatan otot dengan Perubahan panjang tulang selama pertumbuhan, tetapi tidak ada korelasi dengan Perubahan volume otot. Dengan demikian dapat dikatakan bahwa ada korelasi selama pertumbuhan, yang berdasarkan pada unsur tulang

Integrals over Products of Distributions and Coordinate Independence of Zero-Temperature Path Integrals

In perturbative calculations of quantum-statistical zero-temperature path integrals in curvilinear coordinates one encounters Feynman diagrams involving multiple temporal integrals over products of distributions, which are mathematically undefined. In addition, there are terms proportional to powers of Dirac delta-functions at the origin coming from the measure of path integration. We give simple rules for integrating products of distributions in such a way that the results ensure coordinate independence of the path integrals. The rules are derived by using equations of motion and partial integration, while keeping track of certain minimal features originating in the unique definition of all singular integrals in $1 - \epsilon$ dimensions. Our rules yield the same results as the much more cumbersome calculations in 1- epsilon dimensions where the limit epsilon --> 0 is taken at the end. They also agree with the rules found in an independent treatment on a finite time interval.Comment: Author Information under http://www.physik.fu-berlin.de/~kleinert/institution.html . Latest update of paper (including all PS fonts) at http://www.physik.fu-berlin.de/~kleinert/33

Tuning the emission wavelength of Si nanocrystals in SiO2 by oxidation

Si nanocrystals (diameter 2–5 nm) were formed by 35 keV Si + implantation at a fluence of 6 × 1016 Si/cm2 into a 100 nm thick thermally grown SiO2 film on Si (100), followed by thermal annealing at 1100 °C for 10 min. The nanocrystals show a broad photoluminescence spectrum, peaking at 880 nm, attributed to the recombination of quantum confined excitons. Rutherford backscattering spectrometry and transmission electron microscopy show that annealing these samples in flowing O2 at 1000 °C for times up to 30 min results in oxidation of the Si nanocrystals, first close to the SiO2 film surface and later at greater depths. Upon oxidation for 30 min the photoluminescence peak wavelength blueshifts by more than 200 nm. This blueshift is attributed to a quantum size effect in which a reduction of the average nanocrystal size leads to emission at shorter wavelengths. The room temperature luminescence lifetime measured at 700 nm increases from 12 µs for the unoxidized film to 43 µs for the film that was oxidized for 29 min

Hands-On Universe: A Global Program for Education and Public Outreach in Astronomy

Hands-On Universe (HOU) is an educational program that enables students to investigate the Universe while applying tools and concepts from science, math, and technology. Using the Internet, HOU participants around the world request observations from an automated telescope, download images from a large image archive, and analyze them with the aid of user-friendly image processing software. This program is developing now in many countries, including the USA, France, Germany, Sweden, Japan, Australia, and others. A network of telescopes has been established among these countries, many of them remotely operated, as shown in the accompanying demo. Using this feature, students in the classroom are able to make night observations during the day, using a telescope placed in another country. An archive of images taken on large telescopes is also accessible, as well as resources for teachers. Students are also dealing with real research projects, e.g. the search for asteroids, which resulted in the discovery of a Kuiper Belt object by high-school students. Not only Hands-On Universe gives the general public an access to professional astronomy, but it is also a more general tool to demonstrate the use of a complex automated system, the techniques of data processing and automation. Last but not least, through the use of telescopes located in many countries over the globe, a form of powerful and genuine cooperation between teachers and children from various countries is promoted, with a clear educational goal.Comment: 4 pages, 1 figure, to appear in the proceedings of the ADASS X conference, Boston, October 2000, ASP conf. pro

The coupling of a hearing aid loudspeaker membrane to visco-thermal air layers

Hearing aids and their components are becoming smaller. This presents new problems for the acoustical components, such as the loudspeaker. A circular membrane of a hearing aid loudspeaker is modeled in this paper. Neglecting air influences, the membrane and its suspension behave as a mass spring system. However, under operating conditions, thin layers of air on both sides of the membrane influence its behavior. Air can enter and leave these layers at certain locations on the circular edge of the layer. Since these air layers are thin, visco-thermal effects may have to be taken into account. Therefore, the air layers are not modeled by the wave equation, but by the low reduced frequency model that takes these visco-thermal effects into account. The equations of this model are solved in a polar coordinate system, using a wave-based method. The other acoustical parts of the hearing aid loudspeaker, and the membrane itself are modeled by simple lumped models. The emphasis in this paper is on the coupling of the viscothermal air layer model to the mechanical model of the membrane. Coupling of the air layer to other acoustical parts by using an impedance as boundary condition for the layer model, is also described. The resulting model is verified by experiments. The model and the measurements match reasonably well, considering the level of approximation with lumped parts

Further search for a neutral boson with a mass around 9 MeV/c2

Two dedicated experiments on internal pair conversion (IPC) of isoscalar M1 transitions were carried out in order to test a 9 MeV/c2 X-boson scenario. In the 7Li(p,e+e-)8Be reaction at 1.1 MeV proton energy to the predominantly T=0 level at 18.15 MeV, a significant deviation from IPC was observed at large pair correlation angles. In the 11B(d,n e+e-)12C reaction at 1.6 MeV, leading to the 12.71 MeV 1+ level with pure T=0 character, an anomaly was observed at 9 MeV/c2. The compatibility of the results with the scenario is discussed.Comment: 12 pages, 5 figures, 2 table

How Could the Proton Transversity be Measured

The perspectives of two new nonstandard methods of transversal quark polarization measurement are considered: the jet handedness and the so-called "Collins effect" due to spin dependent T-odd fragmentation function responsible for the left-right asymmetry in fragmenting of transversally polarized quarks. Recent experimental indications in favor of these effects are observed: 1.The correlation of the T-odd one-particle fragmentation functions found by DELPHI in $Z\to 2$-jet decay. Integrated over the fraction of longitudinal and transversal momenta, this correlation is of 1.6% order, which means order of 13% for the analyzing power. 2.A rather large ($\approx10$) handedness transversal to the production plane observed in the diffractive production of ($\pi^-\pi^+\pi^-$) triples from nuclei by the $40 {\rm GeV/c}$ $\pi^-$--beam. It shows a clear dynamic origin and resembles the single spin asymmetry behavior. All this makes us hope to use these effects in polarized DIS experiments for transversity measurement. The first estimation of transversity was done by using the azimuthal asymmetry in semi-inclusive DIS recently measured by HERMES and SMC.Comment: 8 pages, Latex, czjphys2.sty. Talk at Int. Workshop "PRAHA-SPIN99", Prague 6-11 Sept 1999. To appear in Czech.J.Phys Supp