Effect of Fertilization and Irrigation on Essential Oils Extracted from Laurel (Laurus nobilis L.) Leaves

This study focuses on the effects of fertilization and irrigation on the percentage of essential oil extracted from laurel (Laurus nobilis L.) leaves. Trees in the Aleppo Ecopark were treated with three different NPK fertilizers and three different irrigation water rates for two consecutive years, while the control group was left untreated. Phosphorus and potassium fertilizers were applied at the end of January, nitrogen fertilizer at the beginning of March. Additional irrigation was applied three times a year in summer (May, July and September). The leaves of each treatment were collected, dried and the essential oil was extracted with a clavinger. In addition, the extracted oil for each treatment was analyzed by gas chromatograph equipped with mass spectrometer. Results have shown that the fertilization and irrigation processes led to an increase in the essential oil percentage that was extracted from bay leaves and affected its quality, giving the highest percentage of oil, reaching 0.93% when treated with 1.5 kg of urea, 0.75 kg of triple superphosphate, 0.75 potassium sulphate and irrigation with 100 liters of water per tree. Fertilization and irrigation also influenced the proportions of essential oil components. Fertilization with 2 kg urea, 1 kg triple superphosphate, 1 kg potassium sulphate and irrigation with 150 litres of water for each tree gave the highest concentration of 1-8 cineole compounds, which reached 50.23%

Analysis of RC Continuous Beams Strengthened with FRP Plates: A Finite Element Model

Strengthening of reinforced concrete (RC) beams with externally bonded fibre reinforced polymer (FRP) plates/sheets technique has become widespread in the last two decades. Although a great deal of research has been conducted on simply supported RC beams, a few studies have been carried out on continuous beams strengthened with FRP composites.  This paper presents a simple uniaxial nonlinear finite-element model (UNFEM) that is able to accurately estimate the load-carrying capacity and the behaviour of RC continuous beams flexurally strengthened with externally bonded FRP plates on both of the upper and lower fibres. A 21-degree of freedom element is proposed with layer-discretization of the cross-sections for finite element (FE) modelling. Realistic nonlinear constitutive relations are employed to describe the stress-strain behaviour of each component of the strengthened beam. The FE model is based on nonlinear fracture mechanics. The interfacial shear and normal stresses in the adhesive layer are presented using an analytical uncoupled cohesive zone model with a mixed-mode fracture criterion. The results of the proposed FE model are verified by comparison with various selected experimental measurements available in the literature. The numerical results of the plated beams (beams strengthened with FRP plates) agreed very well with the experimental results. The use of FRP increased the ultimate load capacity up to 100 % compared with the non-strengthened beams as occurred in series (S). The major objective of the current model is to help engineers’ model FRP-strengthened RC continuous beams in a simple manner

Ethical leadership, management control systems and circular economy in SMEs in an emerging economy, the UAE

Prior literature on the transition to a circular economy has focused primarily on societal, institutional, and technical levels and has paid less attention to people- and organization-driven factors such as leadership and management control. Further, few studies have considered the circular economy in the context of small and medium enterprises in emerging economies. Thus, through this empirical study, we aim to fill these research gaps by investigating the concurrent effects of ethical leadership and management control systems on the extent of the circular economy in small and medium-sized enterprises in the United Arab Emirates. The survey data were collected from 111 enterprises. We performed a confirmatory factor analysis to validate the instrument and tested the theoretical model through structural equation modelling. The findings support our theoretical propositions and show that both ethical leadership and management control systems are positively associated with the extent of circular economy practices in these enterprises. Interestingly, our findings demonstrate that management control systems fully mediate the relationship between ethical leadership and the extent of the circular economy. The results suggest that ethical leadership requires the support of management control systems to convey its positive effects in terms of circular economy practices. Overall, the findings help explain how ethical leadership and management control systems are important driving mechanisms for enabling small and medium enterprises to deploy a circular economy effectively. The implications of these findings for research and practice are also discussed

PRINCIPAL-AGENT PREFERENCES IN IMPERFECT MARKETS: THEORETICAL ANALYSIS ON MURABAHAH AND IJARAH

This paper aims to determine the optimal contract for the principal and the agent in imperfect market, when murabahah and ijarah are used. The financial contracting enforceability approach is employed to determine the contract that maximizes the value of the firm subject to agents’ constraints when the shock is low and high, and regarding market frictions. Furthermore, this approach allows us to assess the level of market frictions that agents may bear in case of low shock and high shocks. Findings reveal that the simulated values of the market frictions’ parameters for both contracts increase when moving from the low shock to the high shock. Such evidence implies that the agent is more likely to cheat and hide significant information about the project when the shock is high. As a response to this higher risk, the simulated values of the profit margin parameters for the principal rise also when the shock is high in order to compensate for the increase of market frictions and mitigate conflicts of interest. By comparing both contracts based on the simulated optimal values of the firm, it is noticeable that the gap between both contracts is very tight, which can be attributed to their common debt-based financial arrangements. However, the results show that ijarah allows the principal and the agent to generate the highest value in case of low shock and high shock, comparing to murabahah. Therefore, ijarah seems to be more attractive for the principal and the agent than murabahah

Mantle Flow Pattern Associated With the Patagonian Slab Window Determined From Azimuthal Anisotropy

Geological processes in Southern Patagonia are affected by the Patagonian slab window, formed by the subduction of the Chile Ridge and subsequent northward migration of the Chile Triple Junction. Using shear wave splitting analysis, we observe strong splitting of up to 2.5 s with an E-W fast direction just south of the triple junction and the edge of the subducting Nazca slab. This region of strong anisotropy is coincident with low uppermost mantle shear velocities and an absence of mantle lithosphere, indicating that the mantle flow occurs in a warm, low-viscosity, 200–300 km wide shallow mantle channel just to the south of the Nazca slab. The region of flow corresponds to a volcanic gap caused by depleted mantle compositions and absence of slab-derived water. In most of Patagonia to the south of this channel, splitting fast directions trend NE-SW consistent with large-scale asthenospheric flow.Fil: Ben Mansour, Walid. Washington University in St. Louis; Estados UnidosFil: Wiens, Douglas A.. Washington University in St. Louis; Estados UnidosFil: Mark, Hannah F.. Washington University in St. Louis; Estados UnidosFil: Russo, Raymond M.. University of Florida; Estados UnidosFil: Richter, Andreas Jorg. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de la Plata. Facultad de Cs.astronomicas y Geofisicas. Laboratorio Maggia.; ArgentinaFil: Marderwald, Eric Rodolfo. Universidad Nacional de la Plata. Facultad de Cs.astronomicas y Geofisicas. Laboratorio Maggia.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Barrientos, Sergio. Universidad de Chile; Chil

Lithospheric erosion in the Patagonian slab window, and implications for glacial isostasy

Author Posting. © American Geophysical Union, 2022. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 49(2), (2022): e2021GL096863, https://doi.org/10.1029/2021GL096863.The Patagonian slab window has been proposed to enhance the solid Earth response to ice mass load changes in the overlying Northern and Southern Patagonian Icefields (NPI and SPI, respectively). Here, we present the first regional seismic velocity model covering the entire north-south extent of the slab window. A slow velocity anomaly in the uppermost mantle indicates warm mantle temperature, low viscosity, and possibly partial melt. Low velocities just below the Moho suggest that the lithospheric mantle has been thermally eroded over the youngest part of the slab window. The slowest part of the anomaly is north of 49°S, implying that the NPI and the northern SPI overlie lower viscosity mantle than the southern SPI. This comprehensive seismic mapping of the slab window provides key evidence supporting the previously hypothesized connection between post-Little Ice Age anthropogenic ice mass loss and rapid geodetically observed glacial isostatic uplift (≥4 cm/yr).The facilities of the IRIS Consortium are supported by the National Science Foundation’s SAGE Award under Cooperative Support Agreement EAR-1851048. The GUANACO project is funded by the National Science Foundation under grants EAR-1714154 to WUSTL and EAR-1714662 to SMU, and Erik R. Ivins was supported by NASA under grant NNH19ZDA001N-GRACEFO.2022-07-1