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101.
Experimental‐numerical research on the seismic performance of URM buildings made of lightweight AAC blocks / Experimentell‐numerische Untersuchung zum seismischen Verhalten von unbewehrten Mauerwerksgebäuden aus Porenbetonblöcken
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Assist. Prof. PhD Andra Penna Professor PhD Guido Magenes Maria Rota Researcher PhD Martina Mandirola MSc Annalisa Rosti MSc 《Mauerwerk》2015,19(2):130-143
Masonry walls constructed with lightweight AAC blocks and thin‐layer mortar meet the increasingly strict requirements of energy efficiency and sustainability. In this sense, they represent an excellent solution for modern buildings, not only for external cladding but also as loadbearing elements. Despite the possible advantages of using lightweight AAC masonry, a specific assessment of its seismic performance is mandatory in order to set design recommendations allowing to reach safety levels consistent with those required for other masonry types complying with EN 1998 standard requirements. A comprehensive study on the seismic performance of unreinforced masonry buildings made of lightweight AAC was carried out in an integrated experimental‐numerical approach. The experimental campaign provided the necessary information to setup a reliable numerical model to be extensively used to assess the seismic performance of a number of prototype AAC masonry buildings with different characteristics, by means of both linear and nonlinear static (pushover) analysis. The results of this systematic numerical assessment were eventually used to draft design recommendations, to set parameters (behaviour factors) to be used in linear analysis and to calibrate rules for simple buildings. 相似文献
102.
Milan P. Allan Simon Berner Martina Corso Thomas Greber Jürg Osterwalder 《Nanoscale research letters》2007,2(2):94-99
High-temperature exposure of a Mo(110) surface to borazine (HBNH)3 leads to the formation of two distinctly different self-assembling nanostructures. Depending on the substrate temperature
during preparation, either well-aligned, ultra-thin boron nanowires or a single-layer stripe structure of hexagonal boron
nitride forms. Both structures show one-dimensional (1D) characteristics, but in directions perpendicular to each other. It
is also possible to grow the two phases in coexistence. The relative weights are controlled by the sample temperature during
preparation. 相似文献
103.
Maurizio Martina Guido Masera Gianluca Piccinini Maurizio Zamboni 《The Journal of VLSI Signal Processing》2003,35(2):137-153
This paper proposes two JPEG 2000 compliant architectures: one for DWT (Discrete Wavelet Transform) and one for IWT (Integer Wavelet Transform) implementation. First of all some theoretical issues about DWT and IWT are discussed, then, starting from transforms characteristics, the architectures are presented showing both performance and cost. In the literature many DWT architectures have been proposed; our implementation is a new architecture that computes the DWT using filters of interest for the forthcoming JPEG 2000 standard. Moreover, we propose a Lifting Scheme based architecture for IWT, JPEG 2000 compliant too. The proposed architectures are able to support real-time streams: the DWT one, which is made of 20,000 cells, with an input throughput of 160 Msamples per second and a clock frequency of 160 MHz, the IWT one, consisting of 50,000 cells, with an input throughput of 4.5 Msamples per second and an internal clock frequency of 108 MHz. 相似文献
104.
Markus Boese Tassilo Heeg Jürgen Schubert Martina Luysberg 《Journal of Materials Science》2006,41(14):4434-4439
Despite their potential application in strain-engineered layer structures, the epitaxial growth of rare earth scandate films on cubic perovskite substrates is not fully understood to date. Here we report on the epitaxy of the orthorhombic GdScO3 and DyScO3 on (001) BaTiO3 and SrTiO3 thin films. In particular, the orientation relationship between the orthorhombic epilayer and the cubic substrate is examined by aberration corrected high-resolution transmission electron microscopy. For all cases investigated, the long axis of the orthorhombic unit cell was found to be perpendicular to the growth direction. 相似文献
105.
Dennis Wichelns John Barry Jr Martina Mu¨ller Megumi Nakao Lisa D. Philo Adam Zitello 《国际水资源开发杂志》2003,19(4):535-552
Competition for water will increase in the northern portion of the Nile River basin, with increases in population and with new and continuing efforts to stimulate economic development, improve income levels and achieve food security. Water scarcity and the inefficient allocation of water can limit the pace of economic development in arid regions, particularly when nations are unable to implement agreements that enhance the sum of net benefits generated with water resources. Much of the discussion regarding water in the northern Nile basin involves the volumetric allocation of water among countries. That focus may limit appreciation of the benefits that might be generated by co-operation involving a larger set of activities, such as international trade and transborder investments. The authors present a conceptual framework that describes how co-operation and international agreements may contribute to achieving the development goals of individual countries, while also enhancing regional net benefits. The authors propose several types of transborder investments that might be helpful in achieving those goals. 相似文献
106.
Martina Aigner Jean-Claude Fardeau Felipe Zapata 《Nutrient Cycling in Agroecosystems》2002,63(1):49-58
Experiments have been carried out in acid soils developed under tropical climates with and without phosphate rock (PR) addition to assess the ability of the Pi strip method to extract available soil P compared with the Isotopic Exchange Kinetics method (IEK). In the Pi strip method strips of filter paper, previously impregnated with iron hydroxide acting as a sink for phosphate ions from soil components, are added to an aqueous soil suspension. The extracted phosphate ions are eluted in diluted sulfuric acid and quantified by a colorimetric method. Available soil P, defined as the amount of phosphate ions that can move from the soil particles to soil solution, is described by three factors: an intensity factor, a quantity factor and a capacity factor. These three factors were determined by the IEK-method. Following the addition of carrier-free 32PO4-ions to soil, the ability of the Pi strip to extract available soil P was assessed: (i) by comparing the quantity of instantaneously exchangeable P (E1) to the quantity extracted with the Pi strip; (ii) by determining the fraction of 32P extracted with the Pi strip, and (iii) by comparing the specific activity (SA) of P present as phosphate ions extracted by the Pi strip to the specific activity of P in the soil solution. It was observed that (i) E1 and the amount extracted with the Pi strip are highly correlated, (ii) the recovery of 32P extracted by the Pi strip varies between 17 and 66%, and (iii) the specific activity of P extracted by the Pi strip is of the same order of magnitude as that of P in the soil solution. In acid soils low in available P, part of the P in aqueous KCl-extracts is presumably not only present as free phosphate ions but also occluded in the form of a soluble complex, whose isotopic exchangeability is significantly lower than that of phosphate ions transferred to the Pi strip. It is concluded from the results that the Pi strip method can be recommended in routine analysis for the determination of the quantity factor. However, this method cannot provide intensity or capacity factors and therefore needs to be complemented by the IEK-method for full characterization of the available soil P status. 相似文献
107.
Dr.-Ing. Georg Scheuerer Dipl.-Ing. Martina Scheuerer 《Forschung im Ingenieurwesen》1992,58(5):128-134
A conservative finite-volume method is employed for simulations of two-phase flows with a two-fluid model using separate conservation
equations for each fluid. The mathematical model is based on ensemble- and phase-averaged transport equations and a set of
simple constitutive laws for interfacial phenomena. The equation system is solved iteratively and in a segregated manner with
the IPSA and PEA algorithms developed by Spalding [7]. The method is verified by comparison with analytical solutions and
experimental data for one-dimensional steady and unsteady two-phase flows. A formal solution error estimation procedure based
on extrapolation techniques is employed to assess the numerical accuracy of the results. 相似文献
108.
A Osterhaus M van de Bildt L Vedder B Martina H Niesters J Vos H van Egmond D Liem R Baumann E Androukaki S Kotomatas A Komnenou B Abou Sidi AB Jiddou ME Barham 《Canadian Metallurgical Quarterly》1998,16(9-10):979-981
During the past few months, more than half of the total population of about 300 highly endangered Mediterranean monk seals (Monachus monachus) on the western Saharan coast of Africa, died in a mysterious disease outbreak. Epizootiological and postmortem findings were reminiscent of similar outbreaks amongst pinniped and cetacean species in recent years, which were caused by an infection with newly discovered morbilliviruses (for review see osterhaus et al.). Virological, as well as toxicological, analysis performed on tissue samples collected from relatively fresh carcasses during the outbreak indicate that infection with a virus closely related to dolphin morbillivirus (DMV), possibly originating from affected dolphins in the same area, was the primary cause of the outbreak. Therefore it is concluded that vaccination with a safe and effective non-replicating vaccine should be considered as a management tool in the conservation of Mediterranean monk seals. 相似文献
109.
G Martina P Piras G Paolo Manca M D'Alpaos S Scuzzarella F Andreassi 《Canadian Metallurgical Quarterly》1996,49(9):981-983
OBJECTIVES: A case of traumatic avulsion of penile skin with amputation of the penis and sectioning of the urethra is described. METHODS/RESULTS: Surgical management included embedding the penis without scrotal skin and subsequent reconstruction utilizing scrotal skin. The patient has recovered sexual activity, although sensitivity has been reduced as a consequence of penile amputation. Six months postoperatively, the patient has reported orgasm during intercourse. CONCLUSIONS: The surgical technique of embedding the penis is safe and preserves elasticity for subsequent reconstruction of the urethral meatus. 相似文献
110.