344 research outputs found
Levitas
No full textThe design and engineering development of two apex connected square woven flat surfaces, each constrained at ground level by three anchors and lifted to form a 3D gridshell whose theoretical geometry is modified by the small sectional profile of the rectangular members made of wood. The warp and weft of the weave are of identical section and made from Italian red oak. The process of artistic investigation is explained and then taken into theoretical designs, computed, and is then tested iteratively through choice of wood, a 33% physical model which is laser surveyed and fed back into the computer model and FEM (Finite Element Method) analysis, and finally followed by a partial full scale mock up, before realising the sculpture at the Arte Sella environmental art park
Digital Design and Wooden Architecture for Arte Sella Land Art Park
Get PDFDigital design is increasingly sinking the construction sector, shaping and validating architecture according to various criteria and introducing the wood industry to the 4.0 approach. Within the study entitled “Architecture at Arte Sella”, parametric design, structural validations and CNC procedures are exploited to help define, control and assess several architectural woodworks, created with famous designers. This contribution describes the design and construction experiences of Atsushi Kitagawara (2017) and Kengo Kuma (2018–2019), the two masterpieces installed in the land art park of Arte Sella (Trento, Italy) and developed, thanks to the Politecnico di Milano team, from design to mock-ups, testing and construction
KODAMA: A Polyhedron Sculpture in the Forest at Arte Sella
No full textKODAMA is the new “sculpture” conceived by Kengo Kuma for Arte Sella—The Contemporary Mountain. The process shows the concept, the development, and the construction of a complex structure in massive wood (Italian larch), a new sculpture in this famous Land art park. After the first options, which have been discussed between the Japanese and the Italian teams, a solution with lattice blades has been chosen. The first phase was to produce different scale mockups, both analogic and digital in order to find proportion and dimensions. All the structure which creates a kind of “porous sphere” (a polyhedron) is made only by one wood section, connected without nails or screws. Old toys, Chidori-like, are the reference and several scaled mockups have been produced with different woods: cedar, larch, fir, and oak. Once assessed the architectural/spatial shape the model has been studied for its structural behaviour thanks to complex software analysis, which have been studied using the parametric model (Rhino-Grasshopper). Models have been used for testing the structure after assessing the real loads (mainly snow and wind). Full scale 1:1 mockup have been realized both analogic and with CNC machines by master carpenters. The final shape is an ideal “Teahouse” space in the middle of the forest, close to Villa Strobele, which will be the new core of Arte Sella, dedicated to famous architects and their ways to conceive art and nature using wood as a creative material
Lightweight rotor design by optimal spar cap offset
Get PDFBend-twist coupling behavior is induced in a blade by displacing the suction side spar cap towards the leading edge, and the pressure side one in the opposite direction. Additional couplings are introduced by rotating the spar cap fibers. The structural configuration of the blade is optimized using an automated design environment. The resulting blade shows significant benefits in terms of mass and loads when compared to the baseline uncoupled one. Finally, the lightweight design concept is used to increase the rotor size, resulting in a larger energy yield for the same hub loads
Microradiography and microcomputed tomography comparative analysis in human bone cores harvested after maxillary sinus augmentation: a pilot study
Get PDFThe aim of this study was to compare microradiography (MR) and microcomputed tomography (μCT) analysis of bone samples following maxillary sinus augmentation at different time periods and determine the relationships between measured area and volume fractions.
MATERIALS AND METHODS:
Lateral window sinus grafts were performed on 10 patients using a mineralized human bone allograft (MHBA). At implant placement, 5-13 months after surgery, 10 bone core biopsies were harvested. Prior to histologic sectioning, bone samples were evaluated with μCT. The morphometric parameters computed by MR and μCT were compared using Pearson's correlation and Bland and Altman analysis and included hard tissue fraction (HV/TV:%), soft tissue fraction (SV/TV:%), vital bone fraction (BV/TV:%) and residual graft fraction (GV/TV:%).
RESULTS:
Strong positive correlation between MR and μCT was found for HV/TV and SV/TV and BV/TV [r = 0.84, 0.84 and 0.69, respectively] but weak for GV/TV [r = 0.10].
CONCLUSION:
μCT technology shows promising potential as an indicator of bone morphology changes; however, caution should be used in interpreting morphometric parameters, as the different methods reveal important biases
First measurement of kaonic helium-4 M-series transitions
Get PDFIn this paper we present the results of a new kaonic helium-4 measurement with a 1.37 g l−1 gaseous target by the SIDDHARTA-2 experiment at the DAΦNE collider. We measured, for the first time, the energies and yields of three transitions belonging to the M-series. Moreover, we improved by a factor about three, the statistical precision of the 2p level energy shift and width induced by the strong interaction, obtaining the most precise measurement for gaseous kaonic helium, and measured the yield of the Lα transition at the employed density, providing a new experimental input to investigate the density dependence of kaonic atoms transitions yield
First measurement of kaonic helium-4 M-series transitions
Get PDFIn this paper we present the results of a new kaonic helium-4 measurement with a 1.37 g l−1 gaseous target by the SIDDHARTA-2 experiment at the DAΦNE collider. We measured, for the first time, the energies and yields of three transitions belonging to the M-series. Moreover, we improved by a factor about three, the statistical precision of the 2p level energy shift and width induced by the strong interaction, obtaining the most precise measurement for gaseous kaonic helium, and measured the yield of the Lα transition at the employed density, providing a new experimental input to investigate the density dependence of kaonic atoms transitions yield
Characterization of CdS sputtering deposition on low temperature pulsed electron deposition Cu(In,Ga)Se2 solar cells
No full textThe present paper reports the investigation of sputtered CdS as a buffer layer in Cu(In,Ga)Se2 (CIGS) solar cells, for a dry-low temperature all in-line production technology method. The CdS film is deposited using radio-frequency magnetron sputtering in argon atmosphere. Compared to the well-known CdS grown by chemical bath deposition, the sputtering technology is feasible for the serial manufacturing process. The morphology and optical transmittance of CdS thin films are studied, as well as the CdS/CIGS interface and the solar cell characteristic. We observe that CdS layer deposited on glass is uniform and continuous with optical transmittance above 90% in the wavelengths range corresponding to the energy gap of the absorber. Current density-voltage (J-V) curve shows an overall efficiency of 6% affected by inhomogeneity at the CIGS/CdS interface. Sputtering deposition is not able to create a homogeneous layer on the absorber irregularities due its growth process. Moreover, Auger depth profile shows oxygen contamination at the interface, due to absorber surface oxidation. Within this work, the main crucial aspects of a new solar cell production technology, as well as related solutions, are reported
Concentración y disponibilidad de fósforo en un suelo hortícola urbano
Get PDFEl fósforo (P) es un macronutriente esencial en el crecimiento vegetal, con bajas entradas al agroecosistema. El manejo agroecológico de los cultivos promueve la fertilidad y diversidad biológica del suelo sin uso de productos de síntesis química. Con el objetivo de evaluar la incorporación de enmiendas sobre la disponibilidad de fósforo en el suelo de la Huerta Experimental de FAUBA se aplicaron 5 tratamientos: Harina de Hueso (HH), Microorganismos (M), Humus (C), Harina de Hueso + Microorganismos (HH+M) y Testigo (T) utilizando un diseño completamente aleatorizado con 6 repeticiones. Pasados 180 días se tomaron muestras de suelo y se analizó el contenido de P total y P extractable. Los tratamientos HH y HH+M aumentaron la concentración de P total y P extractable en suelo, siendo significativo para HH+M, en ambos casos. Se espera poder compartir estos resultados para contribuir a la adopción de prácticas agrícolas sustentables.Fil: Clozza, Micaela Sofía. No especifíca;Fil: Bursztyn Fuentes, Amalia Lara. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Bertotti, Lucila. No especifíca;Fil: Do Carmo, Luis Ignacio. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Química Analítica; ArgentinaFil: Rondanini, Deborah Paola. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Métodos Cuantitativos y Sistemas de Información; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: de Los Rios, Alejandra Maria. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Química Analítica; ArgentinaII Congreso Argentino de AgroecologíaChacoArgentinaSociedad Argentina de Agroecologí
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