Finite pure bending of curved pipes

We present an original treatment for the finite bending of curved pipes with arbitrary cross sections. The curved pipe is successively regarded as a three-dimensional continuum and a shell, and a formulation is proposed for each model. We show that, from a numerical point of view, the finite bending problem is reducible to an axisymmetric analysis augmented with 1 d.f. We also show how to take advantage of this analogy to solve the bending problem using standard axisymmetric FE routine

Control of sand flies with attractive toxic sugar baits (ATSB) and potential impact on non-target organisms in Morocco

International audienceBackground: The persistence and geographical expansion of leishmaniasis is a major public health problem that requires the development of effective integrated vector management strategies for sand fly control. Moreover, these strategies must be economically and environmentally sustainable approaches that can be modified based on the current knowledge of sand fly vector behavior. The efficacy of using attractive toxic sugar baits (ATSB) for sand fly control and the potential impacts of ATSB on non-target organisms in Morocco was investigated. Methods: Sand fly field experiments were conducted in an agricultural area along the flood plain of the Ourika River. Six study sites (600 m x 600 m); three with ``sugar rich'' (with cactus hedges bearing countless ripe fruits) environments and three with ``sugar poor'' (green vegetation only suitable for plant tissue feeding) environments were selected to evaluate ATSB, containing the toxin, dinotefuran. ATSB applications were made either with bait stations or sprayed on non-flowering vegetation. Control sites were established in both sugar rich and sugar poor environments. Field studies evaluating feeding on vegetation treated with attractive (non-toxic) sugar baits (ASB) by non-target arthropods were conducted at both sites with red stained ASB applied to non-flowering vegetation, flowering vegetation, or on bait stations. Results: At both the sites, a single application of ATSB either applied to vegetation or bait stations significantly reduced densities of both female and male sand flies (Phlebotomus papatasi and P. sergenti) for the five-week trial period. Sand fly populations were reduced by 82.8% and 76.9% at sugar poor sites having ATSB applied to vegetation or presented as a bait station, respectively and by 78.7% and 83.2%, respectively at sugar rich sites. The potential impact of ATSB on non-targets, if applied on green non-flowering vegetation and bait stations, was low for all non-target groups as only 1% and 0.7% were stained with non-toxic bait respectively when monitored after 24 hours. Conclusions: The results of this field study demonstrate ATSB effectively controls both female and male sand flies regardless of competing sugar sources. Furthermore, ATSB applied to foliar vegetation and on bait stations has low non-target impact

A numeric-symbolic approach to the problem of localization of plastic flow

A method combining numerical and symbolic computations is presented for deciding whether or not a mechanical state given numerically in terms of its fourth-order tenser of moduli satisfies the localization condition, and more generally, any constitutive restriction on the tenser of moduli having a polynomial form. The idea underlying the method consists in posing the problem not as an optimization problem (minimizing the determinant of the acoustic tenser with respect to direction), but as a polynomial inequality. The polynomiality of the problem is then fully taken advantage of by using a powerful algorithm to solve polynomial inequalities: (a simplified version of) Collins' cylindrical algebraic decomposition algorithm. The method was implemented using the computer algebra system MATHEMATICA, which provides accuracy-controlled symbolic and numerical computations and many built-in functions to handle polynomials. These features make it possible to determine the onset of localization more accurately and more reliably than with the usual optimization-based approaches, which are not guaranteed to converge to the global minimum. The potential of the method is illustrated by addressing loss of ellipticity and loss of strong ellipticity in the case of Gurson's porous material

An adaptive relationship of thermal comfort for the Gulf Cooperation Council (GCC) Countries: The case of offices in Qatar

Escalating building energy expenditure encourages rethinking on thermal comfort delivery in the Gulf Cooperation Council (GCC) countries in warm desert climate. The GCC states do not have an adaptive comfort standard, or its precursor long term field surveys. Therefore, we carried out thermal comfort field studies in Qatar for thirteen months. In ten typical air-conditioned office buildings, 1174 voluntary subjects have completed 3742 questionnaires, while their thermal environments were simultaneously being measured. We found the mean Griffiths comfort temperature to be 24.0 �C. It varied seasonally and also with the indoor temperature. Indoor Griffiths comfort temperature adaptively related with the outdoor temperature. This relationship can be used in buildings of similar nature in the GCC region. The subjects mostly felt cooler sensations. Thermal acceptance was high (82.7%). The offices had very low indoor air movement (median air speed 0.02 m/s), while 80% recorded less than 0.05 m/s. This is below the average air speed of 0.28 m/s, American Society of Heating, Refrigerating and Air-conditioning Engineers permitted. Increased air movement can effectually facilitate an elevated thermal regime, more in sync with outdoor conditions. Adopting variable comfort standards may be made mandatory to achieve the building sustainability goals of the GCC nations. 2017 Elsevier B.V.Qatar National Research Fund through National Priorities Research Program (NPRP ?7-143�2-070) funded this research. The Japan Society for Promotion of Science and The University of Tokyo, Japan provided the instruments used. The responsibility for the views expressed in this article solely rests with the authors

Optimizing the composition profile of a functionally graded interlayer using the adjoint equations.

No abstract provide

Towards an inter-Emirate urban conservation strategy in the United Arab Emirates

SIGLEAvailable from British Library Document Supply Centre-DSC:m02/36649 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

User satisfaction and energy use behavior in offices in Qatar

The occupant behavior significantly contributes to the total energy use in buildings and its understanding is greatly needed in energy analysis/simulation studies. Uncertainties about the occupant behavior adversely affect the building performance predictability of the simulation models. As field data in Qatar on occupant energy use and behavior was unavailable, we conducted an environmental satisfaction and energy use survey in the city of Doha, Qatar in seven office buildings. Building occupants were highly satisfied with their work environments with respect to most of the environmental parameters excepting acoustics. Access to operable controls such as windows, thermostats improved their satisfaction. Subjects in private offices were more satisfied with their work environments. We noted the self-declared productivity of respondents to be high in general. It was significantly higher in offices with better occupant access to temperature controls. Noise level dissatisfaction was the highest in high partitioned cubicle offices and satisfaction was high in open plan offices. These findings provide vital design direction for new offices and environmental systems design and for managerial motivational campaigns. Practical application: Using field study data, we analyzed the occupant behavior and environmental satisfaction in offices in Doha, Qatar. The Middle East in general and Qatar in particular are known to consume enormous energy for buildings leaving a large ecological footprint. The finding of this study informs the designers of air-conditioning systems about the user behavioral patterns. Further, these findings help the building managers in designing targeted energy awareness/saving campaigns, as user motivation is vital in energy saving. ? 2018, The Chartered Institution of Building Services Engineers 2018.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Qatar Foundation funded this research through grant number NPRP 7-143-2-070

Building energy model calibration using automated optimization-based algorithm

Multiple numbers of Building Energy Simulation (BES) programs have been improved and implemented during the last decades. BES models play a crucial role in understanding building energy demands and accelerating the malfunction diagnosis. However, due to the very high number of interacting parameters, most of the developed energy simulation programs do not accurately predict building energy performance under a known condition. Even the energy models which are developed with the very precise assignment of parameters, there is always significant discrepancies between the simulation results and the real-time data measurements. Current study develops an optimization-based framework to calibrate the whole building energy model. The optimization algorithm attempts to set the identified parameters to minimize the error between the simulation results and the real-time measurements. Due to the high number of parameters, the developed optimization algorithm utilizes a Harmony Search algorithm as its search engine coupled with the energy simulation model to accelerate the calibration process. Moreover, to illustrate the efficiency of using the developed framework, a case study of the office building is modeled and calibrated and the statistical analysis was conducted to assess the accuracy of the results. The results of the calibration process show the reliability of the framework. - 2019This work was supported by the Qatar National Research Foundation (QNRF)/National Priorities Research Program (NPRP 7 - 143 - 2 - 070). Authors would like to acknowledge their supports through this research.Scopu