The Stigma of Wasta: The Effect of Wasta on Perceived Competence and Morality

Wasta is an Arabic word that means the use of social connections to obtain benefits that otherwise would not be provided. Wasta plays a very important role in securing of employment in Arab countries. This paper attempts to study the attribution effects of wasta on perceptions of competence and morality. The main hypotheses is that those that use wasta to obtain employment will be perceived as incompetent and immoral irrespective of their true competence and morality. Data gathered from an Egyptian sample supports the hypotheses. Thus, we conclude that wasta may tarnish the image or stigmatize its user.Nepotism, attribution theory

Arid Climate Conditions Vs Water Resources Management in Africa Based on the Sustainable supply chain operations

Abstract-The purpose of this paper is to explore the impact of sustainable supply chain operations on economic, environmental and social performance, which are the three dimensions of corporate sustainability. Africa has been subjected to water stress due to its large part in arid and semi-arid geographical areas and its topographical features and uneven temporal and spatial distribution of rainfall. In this research, an attempt was carried out for water resources management in an arid climate area, the area is the central part of Darb El Arbeain. The study area occupies the central area of Darb EL-Arbeain and bounded by long. 30o 15/ and 30o 25/ E and lat. 23o 55/ and 24o 05/ N, it has an area of about 120 Km2. In this study four suggested exploitation rates of groundwater have been explored using the three-dimensional finite difference flow model (MODFLOW 2005) to simulate the flow system. These scenarios include running the model with abstraction from the aquifers equal 110 %, 180 %, 280 %, and 370 % of calculated initial recharge. The results indicated that the equilibrium could be reached while pumping out from the aquifer in that arid climate area, and the drawdown could be stable after some time depending on the potentiality and heterogeneity of the aquifer

Investigation on the Relationship between Fracture dimensions and Proppant Selection for Shale Gas Reservoir

The Search for new sources of energy has always been motivated by both economical and political reasons. This made the oil and gas industry look into resources that was overlooked before. Shale gas reservoirs represent a huge potential for gas reserves. However, the production process from shale gas is very complex due to the low permeability and the dual porosity nature of shale formation. Many parameters affect the process which in turn make the optimization of these parameters a very complex process. This project aims to create a matlab program to solve for a model of equations to arrive at the optimal parameters for the fracturing stimulation. This program uses the unified fracture design model to calculate the optimum fracture width and length for maximum fracture conductivity. In this project, the fracturing process of the reservoir is analyzed while explaining the role of the proppant agent selection and the fracture width for an optimal productivity after the process. The selection of the proppant is also discussed to arrive to the best proppant selection based on the type, size and concentration of the proppant

Synthesis and Characterization of Phenolic Lipids

Omega-3 polyunsaturated fatty acids (ω3 PUFAs) from fish oils promote well-established health and antiaging benefits that justify their use as functional ingredients in dietary supplements, healthy foods, and nutraceutical products. Dietary supply is needed because human metabolism exhibits limited to synthesize ω3 PUFAs. However, the practical use of such lipids as food ingredients is often limited due to their high susceptibility to oxidation, which is responsible for the undesirable off-flavor and odor of rancid oils, associated with the loss of nutritional value. Produced phenolic lipids were a good solution for all these problems. These phenolic lipids are preferentially produced by enzymatic bioprocesses that exhibit high selectivity toward polyfunctional substrates and mild reaction conditions compared with chemical synthesis pathways. This chapter presents the acylation of phenolic compounds and lipids using enzyme under various operating conditions. In conclusion, the acylation of lipids with natural phenolic compounds resulted in the formation of a lipophilic ester that should be able to stabilize the oil, fats, and emulsions against oxidation. Acylation of lipids to phenolic compounds that have antioxidant properties thus protects the lipids from oxidation, and the phenolic lipid derivatives carry the combined health beneficial properties of lipids and the phenolic molecules

Diseño y caracterización de estructuras resonantes y estrategias de concentración avanzada aplicadasa dispositivos fotónicos

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Óptica, leída el 23-09-2020Efficient low-cost optoelectronic devices are used for many applications, for example, energy production, and sensing. The development of these devices can be step-forward using nanophotonic and nanoplasmonic structures. In this dissertation we propose, design, and analyze several nanostructures to improve the performance of these devices. For energy applications, we select amorphous silicon hydrogenated, and perovskite/crystallinesilicon tandem solar cells. We choose amorphous silicon solar cells because this material is abundant, non-toxic, long-life compared to organic solar cells, and can be fabricated at a low cost. The tandem perovskite/crystalline silicon solar cells are devices with potential power conversion efficiency > 30 %. Our designs are based on dielectric nanostructures. We applied a 1D nanostructure array to the top and bottom of amorphous silicon hydrogenated solar cells, in two separate designs. The absorption enhancement within the auxiliary layers of these devices is dissipated as heat and partially mitigate the defects resulted from the Staebler Wronski effect. A metasurface in the form of multilayer gratings embedded in the active layer of the perovskite top cell of the tandem device, improves the absorption efficiency in the whole device. A sawtooth periodic back texture has been optimized and tested to work with the metasurfacef or further improvement of the device performance. These nanostructures are arranged to maximize the absorption efficiency of the selected solar cells, mainly by reducing their total reflectance. The analysis and calculations are completed by modeling the conditions of the sun illumination, i.e, unpolarized light, and oblique incidence. The performance of the devices is calculated under these conditions...Los dispositivos optoelectrónicos eficientes y de bajo coste se utilizan en muchas aplicaciones. Por ejemplo, en la producción de energía y en sensores. La incorporacion de estructuras nanofotónicas y nanoplasmónicas es un paso adelante en el desarrollo de estos dispositivos. En esta tesis doctoral proponemos, diseñamos y analizamos varias nano-estructuras que mejoran el rendimiento de estos dispositivos. En aplicaciones para energía, hemos selecionado células de silicio amorfo hidrogenado, y células tándem de perovskitas y silicio cristalino. Hemos elegido las células solares de silicio cristalino porque es un material abundante, no tóxico, de larga vida comparada con las células orgánicas y fabricadas a bajo coste. Las células tándem perovskita/silicio cristalino son dispositivos con eficiencias de conversión superiores al 30 %. Nuestros diseños están basados en nano-estructuras dieléctricas. Hemos aplicado una nano-estructura periódica 1D a la superficie anterior y posterior de células solares de silicio amorfo hidrogenado en dos diseños separados. El aumento de la absorción en las capas auxiliares de estas células se disipa como calor y mitiga parcialmente los defectos producidos por el efecto Staebler-Wronski. Una metasuperficie hecha con redes apiladas en capas incluidas en las capa activa de la porción superior de una célula tándem mejora la eficiencia de absorción de todo el dispositivo...Fac. de Ciencias FísicasTRUEunpu

Utilization of Batteries in The Momentary Load Variations of a Cruise Ship

The shipping and cruising industry is considered one of the most important and cheapest transportation, however, it is considered responsible for almost 2.89% of global emissions in 2018. Due to the new regulations provided by IMO, the need to reduce fuel consumption and emissions from the shipping industry becomes imperative. Several technologies have been applied to achieve those challenges, but the main focus of this thesis will be on the utilization of batteries as one of the most promising energy storage technologies, to handle the load variation rather than the operation of the auxiliary diesel engines at an economical loading range. In cruise ship applications, the auxiliary diesel engines are utilized to supply the power required for the auxiliary loads and thruster motors, usually, thruster motors operate close to harbors. So, to ensure power availability, the auxiliary diesel engines usually run at low loading levels. The optimum operating point for the diesel engines is at 80% of loading, if that percentage decreases, both fuel consumption, and NOx emissions increased exponentially, moreover, the engine’s lifetime will be reduced and more maintenance will be required. By utilizing batteries, it will be capable of providing the required power for the operation of thruster motors or during peak loading periods rather than the operation of all available auxiliary diesel engines at low loading levels. The presented study focused on four different scenarios with different battery-pack sizes, showing the space required for each scenario and the operating profile of each diesel engine indicating the fuel consumption with and without the presence of batteries. The first scenario utilized a 940-kWh battery pack, which increased the efficiency of the running engines close to the optimum operating level. The last scenario utilized a 3240-kWh battery pack, which enables the shutdown of the auxiliary engines during the operation of thruster motors or peak loading. By using the large battery model scenario, half the number of diesel engines will not be required in the future new builds of a cruise ship. This will not only improve the fuel consumption efficiency and reduce emissions, moreover, the maintenance and overall build cost will also be reduced. Technical and economic analysis is presented showing the payback period of the batteries with different fuel and battery price options. The payback period is highly affected by the saving associated with fuel costs and the price of batteries

Multi-objective optimization of building energy design to reconcile collective and private perspectives: CO2-eq vs. Discounted payback time

Building energy design is a multi-objective optimization problem where collective and private perspectives conflict each other. For instance, whereas the collectivity pursues the minimization of environmental impact, the private pursues the maximization of financial viability. Solving such trade-off design problems usually involves a big computational cost for exploring a huge solution domain including a large number of design options. To reduce that computational cost, a bi-objective simulation-based optimization algorithm, developed in a previous study, is applied in the present investigation. The algorithm is implemented for minimizing the CO2-eq emissions and the discounted payback time (DPB) of a single-family house in cold climate, where 13,456 design solutions including building envelope and heating system options are explored and compared to a predefined reference case. The whole building life is considered by assuming a calculation period of 30 years. The results show that the type of heating system significantly affects energy performance; notably, the ground source heat pump leads to the highest reduction in CO2-eq emissions, around 1300 kgCO2-eq/m2, with 17 year DPB; the oil fire boiler can provide the lowest DPB, equal to 8.5 years, with 850 kgCO2-eq/m2 reduction. In addition, it is shown that using too high levels of thermal insulation is not an effective solution as it causes unacceptable levels of summertime overheating. Finally a multi-objective decision making approach is proposed in order to enable the stakeholders to choice among the optimal solutions according to the weight given to each objective, and thus to each perspectiv

Compact modeling of multiple gate mos devices.

Aquesta tesi doctoral presenta models analítics electrostàtics i de transport de diferents tipus de transistors MOSFET de porta múltiple: Double-Gate (DG) MOSFET, Gate-All-Around MOSFETs i FinFETs.Les estructures de porta múltiple són les més adequades per aconseguir la miniaturització dels circuits CMOS per sota dels 50 nm de longitud de canal. La reducció del tamany implica més velocitat i més densitat de circuits a un xip, però també dóna lloc a problemes (efectes de canal curt) que empitjoren les prestacions dels transistors; aquests problemes es deuen a un control més deficient del canal per la porta, que causa un augment del corrent de fuites (degradant la relació on/off del corrent) i disminució de la resistència de sortida (degradant el guany). Amb les estructures de porta múltiple el control electrostàtic del canal per la porta augmenta considerablement i els efectes de canal curt es redueixen dràsticament.El disseny de circuits nanomètrics necessita models acurats dels dispositius MOS de porta múltiple. A més, els models han d'ésser analítics, de manera que els puguin utilitzar els simuladors de circuits, amb temps de simulació petits i sense problemes de convergencia.Aquesta tesi presenta models analítics dels transistors multi-gate MOSFETs, tant per al comportament electrostàtic com pels mecanismes de transport. L'electrostàtica ha estat modelada a partir de l'equació de Poisson en 2 o 3 dimensions. S'han desenvolupat tècniques per resoldre analíticament l'equació de Poisson. El fet de què els models es derivin d'una anàlisi bidimensional o tridimensional fa que els efectes de canal curt s'incloguin de manera física, sense paràmetres empírics. Els models analítics resultants s'han comparat amb simulacions numèriques bidimensionals i tridimensionals, i s'ha observat una concordància quasi perfecta fins als 20 nm de longitud de canal. En el cas del FinFET, a més, s'ha pogut realitzar una comparació amb mesures experimentals, que ha resultat bastant exitosa.Aquesta tesi està recolzada per un total 7 articles publicats o acceptats a revistes internacionals, i dos més d'enviats.En esta tesis hemos estudiado las características de los dispositivos MOSFET nodopados de puerta múltiple (multiple-gate MOSFETs), con dimensiones nanométricas.Hemos introducido modelos compactos de los efectos de canal corto (SCEs) para trestipos de dispositivos MOS de puerta múltiple (surrounding-gate MOSFET, double-gateMOSFET, y FinFET). Se han conseguido modelar los principales parámetros afectadospor los efectos de canal corto. Este trabajo supone un avance muy importante en el modelado de los nuevosdispositivos nanométricos MOS de puerta múltiple. Una buena prueba de ello es que lamayor parte de los resultados presentados en esta tesis se han publicado (o estánaceptados para publicación) en prestigiosas revistas internacionales y en actas decongresos internacionales de reconocido prestigio

Axial and flexural behaviour of reinforced concrete-filled FRP tubes experimental and theoretical studies

Corrosion of steel reinforcement causes continual degradation to the worldwide infrastructures and it has prompted the need for challenges to those involved with reinforced concrete structures. Recently, the use of fibre-reinforced polymers (FRP) tubes as structurally integrated stay-in-place forms for concrete members, such as beams, columns, bridge piers, piles and fender piles has emerged as an innovative solution to the corrosion problem. In such integrated systems, the FRP tubes may act as a permanent form, often as a protective jacket for concrete, and especially as external reinforcement in the primary and secondary directions such as for confinement. Furthermore, the use of concrete-filled FRP tubes (CFFT) technique is predicated on performance attributes linked to their high strength-to-weight ratios, expand the service life of structures, enhance corrosion resistance, and potentially high durability. This dissertation evaluates the axial and flexural performances of reinforced CFFT through experimental and analytical investigations. The details description and the findings of the investigations are presented through seven articles. To fulfill the objectives of this research, an experimental program has been designed including pure compression tests (33 specimens), axial-eccentric load tests (4 specimens) and pure flexure tests (10 specimens). Experimental investigations of the behaviour of CFFT have generally been carried out without using internal longitudinal reinforcement. The CFFT system of this study consists basically of filament-wound glass FRP tubes filled with concrete and reinforced internally with steel or FRP bars. Five types of new FRP tubes have been used with different thicknesses and two different diameters, 152 and 213 mm. Pure compression tests have been conducted on 40 specimens with a total height ranging from 305 mm to 1520 mm. One of the main objectives of testing these specimens is to evaluate the design equations of the North American codes and design guidelines to predict the ultimate load capacities of reinforced and unreinforced short CFFT columns. In addition, the effect of three parameters and their interactions on the buckling behaviour were investigated for these specimens; namely, the FRP tube thickness, concrete compressive strength, and slenderness ratio. The effect of eccentric load on the behaviour of four CFFT specimens of diameters 152mm and long 912mm, has been evaluated using four different eccentricity values (15, 30, 45 and 60 mm). Based on the finding of experimental and theoretical investigation for the CFFT columns, a new confinement model is proposed for the confined concrete compressive strength of the CFFT cylinders. Also, the design equations are modified to accurately predict the ultimate and yield loads capacities of internally reinforced and unreinforced short CFFT columns. In addition, the theoretical analysis was utilized to correlate the slenderness ratio of the CFFT columns to various material characteristics and geometric properties of the FRP tubes and concrete. It was found that a slenderness ratio of 12 gave a safe value for the design purposes. However a more precise formula for the slenderness ratio was proposed to control the buckling mode of failure. Pure flexural tests have been conducted on 10 RCFFT and RC beams of a total length 2000 mm with constant diameter 213 mm. The test variables were the type of internal reinforcements (steel or GFRP bars), the FRP tube thickness, concrete compressive strength and the type of transverse reinforcements (spiral steel or FRP tubes). The influence of the considered variables on the flexural behaviour of the tested RCFFT beams is presented. A simplified analytical method is developed to predict the yield and resisting moments corresponding to the failure modes of the tested RCFFT beams. The analysis was conducted according to the equations derived from linear elastic analysis. This analysis was found to be acceptable for predicting the ultimate and yield moments capacities of the FRP or steel-RCFFT beams. In addition, an analytical investigation to examine the validity of the available design provisions for predicting the load-deflection response of CFFT is conducted. The effective moments of inertia of the tested beams are analyzed using the different available code, manuals and design guidelines equations. The results of the analysis are compared with the experimental values. It has been found that the predicted tension stiffening for steel or FRP-RCFFT beams using the conventional equations (steel or FRP-RC member) is underestimated and hence the predicted deflections are overestimated. Based on the experimental data obtained in this study, new proposed equations and a modified expression for the effective moment of inertia of a simply supported CFFT beams reinforced with steel or GFRP bars are introduced