197,660 research outputs found
Acanthogyrus (Acanthosentis) barmeshoori Amin, Gholami, Akhlaghi & Heckman 2013
No full textAcanthogyrus (Acanthosentis) barmeshoori Amin, Gholami, Akhlaghi & Heckman, 2013 Host: Aphanius farsicus Locality: Maharlou Lake, Fars Province (Amin et al. 2013 a)Published as part of Tavakol, Sareh, Amin, Omar M., Luus-Powell, Wilmien J. & Halajian, Ali, 2015, The acanthocephalan fauna of Iran, a check list, pp. 237-258 in Zootaxa 4033 (2) on page 241, DOI: 10.11646/zootaxa.4033.2.3, http://zenodo.org/record/23377
Experimental parametric study on dynamic divergence instability and chaos of circular cylindrical shells conveying airflow
No full textExperiments have shown that soft circular cylindrical shells supported at both ends and conveying airflow lose stability by so-called dynamic divergence. The present study investigates experimentally the effect of geometric parameters of a silicone rubber shell, namely length-to-radius (L/R) and thickness-to-radius (h/R) ratios, on the dynamic divergence instability. Bifurcation diagrams of the rms velocity of the shell vibration versus flow velocity are obtained for different shells, displaying a strongly subcritical nonlinear behaviour. Then, the onset of instability and post-critical behaviour of the shells are compared: (i) thinner and longer shells lose stability at lower flow velocities, (ii) thinner shells have higher rms vibration velocity, and (iii) by decreasing L/R, the subcritical behaviour is weakened for thin shells, while it is strengthened for thick shells. The existence of chaos and the influence of geometric parameters on the chaotic behaviour of the system are deeply examined by means of several measures
A modelling methodology for a solar energy-efficient neighbourhood
No full textPurpose: The purpose of this paper is to present a methodology to quantify the solar energy potential for applying photovoltaic systems and find an efficient geometry for urban blocks to obtain a better quality of daylighting in terms of continuous daylight autonomy (DA) and spatial DA with less energy consumption. Design/methodology/approach: The paper is based on a complete simulation of the topography and micro-climate of the area under study. Simulations were performed using ArcGIS and Rhinoceros and urban daylight (UD) and urban modeling interface plugin for a neighborhood in the region of Narmak in Tehran, Iran. Five configurations of a neighborhood were compared using simulations. Findings: It was found that the impact of the geometrical form on daylight gain and energy consumption is significant and the terraced model is the most suitable form for obtaining a constant floor area ratio. Furthermore, it is an optimal form of urban blocks to gain the most energy through photovoltaic systems in the neighborhood as it would be able to satisfy about 42 percent of the energy needs. Originality/value: Planning to achieve sufficient energy factors in cities is a difficult task, since urban planners often do not have adequate technical knowledge to measure the contribution of solar energy in urban plans and this paper aims to introduce a comprehensive modeling methodology by which the urban energy planning can be used and understood in the urban context to make it completely clear as a strategy of implementation
Dynamic divergence of circular cylindrical shells conveying airflow
No full textExperimental studies have shown that circular cylindrical shells, supported at both ends, conveying internal fluid flow can lose stability by dynamic divergence when the shell is highly pliable. This is an instability phenomenon starting as a divergence, with amplitude comparable to the shell radius, that largely constrains the flow. This results in pressure building up and reopening the shell, triggering a dynamic instability. The characteristics of dynamic divergence instability are studied in-depth in this paper for the first time to elucidate the nature and characteristics of this phenomenon. Experiments have been conducted on an elastomer (silicone rubber) thin circular cylindrical shell clamped at both ends and subjected to internal airflow. Bifurcation diagrams have been obtained by varying the flow velocity as the control parameter, exhibiting strong subcritical behaviour and large hysteresis in the flow velocity for the onset and cessation of dynamic instability. The possible existence of a chaotic component in the oscillations was firstly discerned by looking at high-resolution photos taken with a high-speed camera. The existence of chaos in the dynamic response following the initial divergence was then confirmed by means of several qualitative and quantitative measures and criteria for chaos, such as phase plane plots, Poincaré maps, power spectra, the largest Lyapunov exponent, autocorrelation, and probability density function. All these measures have shown that the chaotic nature of dynamic divergence may be intensified or weakened depending on the flow velocity. The results demonstrate that generally at higher flow velocities the oscillations display more complex nonlinear dynamics
Generation Capacity Expansion with CO2 Emission and Transmission Constraints in an Oligopolistic Market
No full textThe European Union is committed to cut Greenhouse Gas emissions (GHGs) by 30% of 1990 levels by 2020; other countries are committed to make similar reductions under a global agreement. Some technical options are available on the supply side, to reduce GHG and other harmful emissions by the power sector. Therefore, it is important to analyze what type of power generation technologies will be chosen by companies under different CO2 mitigation targets. Several models look into Generation Expansion Planning in oligopolistic markets; however, they do not consider the impact of CO2 reduction targets and the transmission constraints together. This study presents a Generation Expansion planning model with transmission constraints for analyzing the implications of CO2 emission mitigation constraints for investment decisions in oligopolistic electricity markets. The results of the model are presented with reference to the Italian power sector, responsible for 32% of national CO2 emissions
Optimal operation of renewable energy communities under demand response programs
No full textWithin the context of renewable energy communities, this paper focuses on optimal operation of producers equipped with energy storage systems in the presence of demand response. A novel strategy for optimal scheduling of the storage systems of the community members under price-volume demand response programs, is devised. The underlying optimization problem is designed as a low-complexity mixed-integer linear program that scales well with the community size. An algorithm for redistributing the demand response rewards corresponding to the optimal solution is also developed in order to guarantee fairness among participants. The proposed approach is evaluated using two different objective functions through extensive numerical simulations. In all cases, economic benefits are demonstrated for producers that participate in a community rather than operating independently
Agro-environmental assessment of recycling abattoir blood meal powder as an organic fertilizer using soil quality index and hazard quotient
No full textPurpose This study assessed the fertilizing potential and environmental impacts of recycling the blood meal powder (BMP) produced in the abattoir as an organic fertilizer in agriculture.Method In this study, a 70-day laboratory incubation experiment was conducted using a clayey calcareous soil to study the effects of adding abattoir BMP at three rates (1.5, 3.0, and 6.0 ton ha-1). At the end of the incubation period, the pH value, total C and N, inorganic N, and availability of macro- and micronutrient minerals (P, K, Cu, Fe, Mn, Ni, and Zn) were measured. Soil basal respiration, substrate-induced respiration, the abundance of culturable bacteria, fungi, and azotobacter, and dehydrogenase, alkaline and acid phosphomonoesterase, cellulase, invertase, protease, and urease enzymes activities were also determined as biochemical indicators of soil fertility.Results The results showed that the BMP has potential as fertilizer because it increased C, N, P, and Zn as compared to the control soil. Furthermore, the abundance of culturable microorganisms and dehydrogenase activity increased in the amended soil, whereas the other soil enzyme activities and basal respiration did not show an increase. The calculation of the Hazard Quotient (HQ) and the soil quality index (SQI) indicated that 3.0-ton BMP ha-1 is an appropriate treatment to improve soil quality without environmental hazards.Conclusion The results indicate that abattoir BMP application increased the fertility status of calcareous soil without environmental threats
Tripose: A weakly-supervised 3d human pose estimation via triangulation from video
No full textGholami M, Rezaei A, Rhodin H, Ward R, Wang ZJ. Tripose: A weakly-supervised 3d human pose estimation via triangulation from video. arXiv preprint arXiv:2105.06599. 2021
A comparison of energy and thermal performance of rooftop greenhouses and green roofs in Mediterranean climate: A hygrothermal assessment in WuFi
No full textIn urban areas, a considerable proportion of energy demand is allocated to buildings. Since rooftops constitute one-fourth of all urban surfaces, an increasing amount of attention is paid to achieving the most efficient shapes and component designs compatible with every climate and urban context, for rooftops of varying sizes. In this study, three types of rooftop technologies, namely insulated, green roof, and rooftop greenhouse, are evaluated for energy and thermal performance using computer simulations. Water surface exposure, absorption, and intrusion are the three important factors in the calculation of hygrothermal models that impact energy consumption and building envelope performance; however, a few studies are specifically focused on providing realistic results in multi-dimensional hygrothermal models and the assessment of the impact of moisture in roofing solutions. This paper aims at evaluating the performance of three different roofing technologies through a two-dimensional hygrothermal simulation in software WUFI. To accomplish this, a precise localized microclimate model of a complex urban context on the scale of a neighborhood was employed to evaluate the cooling and heating loads of the buildings, the impact of the water content in the green roof on the thermal behavior of the roof surface, and the feasibility of designing a building with nearly zero cooling needs. A two-story building in the city center of Bologna, Italy is modelled. Simulation results have shown that during the cooling period, the performance of the designed rooftop greenhouse is the most effective by 50% reduction in cooling loads. Besides, the impact of moisture in green roofs has been detected as a negative factor for thermal and energy performance of the building in the Mediterranean climate. The results ultimately highlighted the capability of passively-designed rooftop greenhouses to create a building with nearly zero cooling needs
Self-Supervised 3D Human Pose Estimation in Static Video Via Neural Rendering
No full textGholami M, Rezaei A, Rhodin H, Ward R, Wang ZJ. Self-Supervised 3D Human Pose Estimation in Static Video Via Neural Rendering. Neurocomputing. 2022;488:97-106
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