48 research outputs found

    Effects of the intensity of design live load on the seismic design modification factors of reinforced concrete frames

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    Seismic design modification factors that include the response modification factor (R), the overstrength factor (Ω), and the displacement amplification factor (Cd) play a significant role in the seismic design of structures. The recommended values for these factors in seismic design codes are empirical and do not account for the differences in the intensity of the design live load in structures. This study investigates the change in the value of these factors as a result of the change in the intensity of the design live load. For this purpose, eighteen reinforced concrete frames with the different number of stories and ductility classes were designed and analyzed. Nonlinear static analysis was used to calculate the capacity curve of frames and their seismic response modification factors. Results indicated that the values of Ω and Cd for both low and high-ductile reinforced concrete frames decreased slightly as the intensity of design live load increased. An increase in the intensity of the design live load increased the R-factor in the high-ductile RC frames

    A New Adaptive Rate IR-HARQ Combining with AMC

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    In this paper, we analyze a new cross layer combining scheme of adaptive modulation and coding (AMC) at the physical layer and hybrid automatic repeat request (HARQ) protocol at the data link layer. Our purpose is to improve the performance of the communication system in terms of throughput and errors. We propose a new adaptive HARQ protocol based on the estimated mutual information in addition to signal to noise ratio as channel state information (CSI), which are unavailable at the receiver. Unlike the traditional protocols, the transmitter is aware of the transmission mode only, not the instantaneous CSI, which minimize the load on the feedback channel. The transmission is supposed to be done over block fading channel. Mathematical formulation is improved for the performance criterions, in terms of throughput of the new HARQ, average number of transmissions and the spectral efficiency of the AMC/HARQ. The comparison with the traditional variable rate HARQ shows that our new adaptive HARQ protocol provides an upper bound for the throughput. In addition, the simulation results show that, a small number of transmissions, is enough to reach the maximum spectral efficiency while maintaining the error probabilities under certain acceptable level

    Evaluation of Nutritional, Phytochemical, and Mineral Composition of Selected Medicinal Plants for Therapeutic Uses from Cold Desert of Western Himalaya

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    The aim of this study was to determine the elemental and nutritive values of leaf parts of 10 selected wild medicinal plants, Acer pictum, Acer caecium, Betula utilis, Oxalis corniculata, Euphorbia pilosa, Heracleum lanatum, Urtica dioica, Berberis lycium, Berberis asiaticaand, and Quercus ilex, collected from the high hills of the Chitkul range in district Kinnaur, Western Himalaya. The nutritional characteristics of medicinal plant species were analyzed by using muffle furnace and micro-Kjeldahl methods, and the mineral content in plants was analyzed through atomic absorption spectrometry. The highest percentage of used value was reported in Betula utilis (0.42) and the lowest in Quercus ilex (0.17). In this study, it was found that new generations are not much interested in traditional knowledge of ethnomedicinal plants due to modernization in society. Therefore, there is an urgent need to document ethnomedicinal plants along with their phytochemical and minerals analysis in study sites. It was found that rural people in western Himalaya are dependent on wild medicinal plants, and certain steps must be taken to conserve these plants from extinction in the cold desert of Himalayan region. They are an alternative source of medicine because they contain saponin, alkaloid, and flavonoid etc. as well as minerals. The leaves used for analysis possesses good mineral content, such as Na, N, K, P, Zn, Fe, Cu, Mn, Ca, Mg, and S. Hence, in the current study it was observed that medicinal plants are not only used for therapeutic purposes, but they can also be used as nutritional supplements

    A Lung Segmental Model of Chronic <em>Pseudomonas</em> Infection in Sheep

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    Chronic lung infection with Pseudomonas aeruginosa is a major contributor to morbidity, mortality and premature death in cystic fibrosis. A new paradigm for managing such infections is needed, as are relevant and translatable animal models to identify and test concepts. We sought to improve on limitations associated with existing models of infection in small animals through developing a lung segmental model of chronic Pseudomonas infection in sheep.Using local lung instillation of P. aeruginosa suspended in agar beads we were able to demonstrate that such infection led to the development of a suppurative, necrotising and pyogranulomatous pneumonia centred on the instilled beads. No overt evidence of organ or systemic compromise was apparent in any animal during the course of infection. Infection persisted in the lungs of individual animals for as long as 66 days after initial instillation. Quantitative microbiology applied to bronchoalveolar lavage fluid derived from infected segments proved an insensitive index of the presence of significant infection in lung tissue (>10(4) cfu/g).The agar bead model of chronic P. aeruginosa lung infection in sheep is a relevant platform to investigate both the pathobiology of such infections as well as novel approaches to their diagnosis and therapy. Particular ethical benefits relate to the model in terms of refining existing approaches by compromising a smaller proportion of the lung with infection and facilitating longitudinal assessment by bronchoscopy, and also potentially reducing animal numbers through facilitating within-animal comparisons of differential therapeutic approaches

    Multi-body Integrated Vehicle-Occupant Models for Collision Mitigation and Vehicle Safety using Dynamics Control Systems

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    The aim of this paper is to investigate the effect of vehicle dynamics control systems (VDCS) on both the collision of the vehicle body and the kinematic behaviour of the vehicle's occupant in case of offset frontal vehicle-to-vehicle collision. A unique 6-Degree-of-Freedom (6-DOF) vehicle dynamics/crash mathematical model and a simplified lumped mass occupant model are developed. The first model is used to define the vehicle body crash parameters and it integrates a vehicle dynamics model with a vehicle front-end structure model. The second model aims to predict the effect of VDCS on the kinematics of the occupant. It is shown from the numerical simulations that the vehicle dynamics/crash response and occupant behaviour can be captured and analysed quickly and accurately. Furthermore, it is shown that the VDCS can affect the crash characteristics positively and the occupant behaviour is improved

    Frequency domain model of power amplifier for OFDM signals

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    Effects of the intensity of design live load on the seismic design modification factors of reinforced concrete frames

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    Abstract Seismic design modification factors that include the response modification factor (R), the overstrength factor (Ω), and the displacement amplification factor (Cd) play a significant role in the seismic design of structures. The recommended values for these factors in seismic design codes are empirical and do not account for the differences in the intensity of the design live load in structures. This study investigates the change in the value of these factors as a result of the change in the intensity of the design live load. For this purpose, eighteen reinforced concrete frames with the different number of stories and ductility classes were designed and analyzed. Nonlinear static analysis was used to calculate the capacity curve of frames and their seismic response modification factors. Results indicated that the values of Ω and Cd for both low and high-ductile reinforced concrete frames decreased slightly as the intensity of design live load increased. An increase in the intensity of the design live load increased the R-factor in the high-ductile RC frames.</jats:p
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