Investigation of the trends of electricity demands in Jordan and its susceptibility to the ambient air temperature towards sustainable electricity generation

Background: Efficient production and reliable availability of electricity requires comprehensive understanding of load demand trends to plan and match production with consumption. Although electricity demand depends on a combination of cultural and economic conditions, weather conditions remain as the major driver. With increased capabilities of accurate predictions of weather, the importance of investigating and quantifying its impact on electricity demand becomes obvious. The electrical system in Jordan has been facing several challenges including the failure to respond to increased demands induced by extreme temperatures. This paper covers a clear gap in literature through presenting a detailed investigation of the electricity consumption trends and in identifying the susceptibility of these trends to weather. Methods: This study relies on the statistical processing and analysis, through modeling of hourly electricity demands in Jordan in the period of 10 years between 2007 and 2016. Actual weather data was used employing the degree-day approach. The monthly, daily, and hourly seasonal variation indices were determined. Optimally formulated piecewise functions were used to track the thermal comfort zone and rate of increase in electricity demand for temperatures beyond it for each year. Moreover, the elasticity of polynomial functions was adopted to identify saturation points to thermally map the electricity consumption. Results: The developed models successfully described the relationship between the daily electricity demand and the mean daily ambient temperature. The average comfort zone width was 4 °C and the average mean base temperature was 17.9 °C. The sensitivity of electricity demand to both high and low temperatures has increased on average, with 11% and 16.4% to hot and cold weather, respectively. Finally, the electricity demand in cooling was found to saturate at 32.9 °C, whereas it saturates for heating at 4.7 °C. Conclusions: The electricity demand in Jordan observes seasonal trends in a consistent and predictable manner. An optimally formulated piecewise function successfully tracked the thermal comfort zone and the rate of increase in electricity demand for temperatures beyond it for each year of the study period. Finally, saturation heating and cooling temperatures were acquired from the elasticity of the daily electricity demands modeled against daily HDD and CDD

External heat losses in small turbochargers: Model and experiments

[EN] The behavior of small turbochargers is deeply affected by heat transfer phenomena. The external heat losses of these machines are studied and a simplified model that takes into account both radiation and convective mechanisms has been proposed. The model has been adjusted in a turbocharger test bench for two different turbochargers, later on it has been validated against experimental measurements on an engine test bench. Finally, the model has been used to estimate the most important external heat flows among the different elements of the turbocharger, showing the operative points in which external heat transfer in turbochargers cannot be neglected. (C) 2014 Elsevier Ltd. All rights reserved.This work has been financial supported by Jaguar Land Rover Ltd.Payri González, F.; Olmeda, P.; Arnau Martínez, FJ.; Dombrovsky, A.; Smith, L. (2014). External heat losses in small turbochargers: Model and experiments. Energy. 71:534-546. https://doi.org/10.1016/j.energy.2014.04.096S5345467

An adapted heat transfer model for engines with tumble motion

In the last years, a growing interest about increasing the engine efficiency has led to the development of new engine technologies. The accurate determination of the heat transfer across the combustion chamber walls is highly relevant to perform a valid thermal balance while evaluating the potential of new engine concepts. Several works dealing with heat transfer correlations that consider the swirl motion are found in the literature; however, there is a lack of works dealing with heat transfer correlations which take into account the effect of the tumble movement. In this work, a new heat transfer model accounting for the tumble motion is presented. A two stroke HSDI Diesel engine with high tumble and no swirl is used to perform the theoretical study, the model development and its final calibration. Initially, a theoretical analysis of the gas movement phenomena is carried out based on CFD results and then, a model is developed and calibrated based on a skip-fire testing technique. Finally, a sensitivity study focused on evaluating the model robustness is performed. The results confirm an average RMSE reduction of 70% with respect to the Woschni model, being this consistent improvement qualitatively evidenced in the instantaneous heat transfer evolutionThe support of the Spanish Ministry of Economy and Competitiveness (TRA2013-41348-R) is greatly acknowledged.Olmeda González, PC.; Martín Díaz, J.; Novella Rosa, R.; Carreño, R. (2015). An adapted heat transfer model for engines with tumble motion. Applied Energy. 158:190-202. https://doi.org/10.1016/j.apenergy.2015.08.051S19020215

A study on the internal convection in small turbochargers. Proposal of heat transfer convective coefficients

Nowadays turbochargers play an important role in improving internal combustion engines (ICE) performance. Usually, engine manufacturers use computer codes to predict the behaviour of both engine and turbocharger, the later by means of measured look-up maps. Using look-up maps different problems arise, being one of the most important the difference in heat transfer between the current operating condition and the conditions at which maps were measured. These effects are very important at low to medium turbocharger speeds (typical condition of urban driving conditions) where heat transfer can even be higher than mechanical power. In this work, the different convective heat transfer phenomena inside these kind of machines have been measured and analysed. Besides, general correlations for these flows, based on dimensionless numbers, are fitted and validated in three different turbochargers. The applicability of the model is shown by comparison the main results obtained when the model is used and not, improving up to 20 C the predicted turbine outlet temperature. The main advantages of applying these correlations rely on predicting fluids outlet temperatures (compressor, turbine, oil and coolant). The former is needed to feed accurately ICE model, turbine outlet temperature is important for aftertreatment device modelling while oil and coolant temperatures are important in order to design optimum cooling systems.This work has been partially supported by the Spanish Ministerio de Economa y Competitividad through grant no. TRA2012-36954. The equipment used in this work has been partially supported by FEDER project funds "Dotacion de infraestructuras cientifico tecnicas para el Centro Integral de Mejora Energetica y Medioambiental de Sistemas de Transporte (CiMeT), (FEDER-ICTS-2012-06)", framed in the operational program of unique scientific and technical infrastructure of the Ministry of Science and Innovation of Spain.Serrano Cruz, JR.; Olmeda González, PC.; Arnau Martínez, FJ.; Reyes Belmonte, MÁ.; Tartoussi, H. (2015). A study on the internal convection in small turbochargers. Proposal of heat transfer convective coefficients. Applied Thermal Engineering. 89:587-599. https://doi.org/10.1016/j.applthermaleng.2015.06.053S5875998

The Gly2019Ser mutation in LRRK2 is not fully penetrant in familial Parkinson's disease: the GenePD study

<p>Abstract</p> <p>Background</p> <p>We report age-dependent penetrance estimates for leucine-rich repeat kinase 2 (<it>LRRK2</it>)-related Parkinson's disease (PD) in a large sample of familial PD. The most frequently seen <it>LRRK2 </it>mutation, Gly2019Ser (G2019S), is associated with approximately 5 to 6% of familial PD cases and 1 to 2% of idiopathic cases, making it the most common known genetic cause of PD. Studies of the penetrance of <it>LRRK2 </it>mutations have produced a wide range of estimates, possibly due to differences in study design and recruitment, including in particular differences between samples of familial PD versus sporadic PD.</p> <p>Methods</p> <p>A sample, including 903 affected and 58 unaffected members from 509 families ascertained for having two or more PD-affected members, 126 randomly ascertained PD patients and 197 controls, was screened for five different <it>LRRK2 </it>mutations. Penetrance was estimated in families of <it>LRRK2 </it>carriers with consideration of the inherent bias towards increased penetrance in a familial sample.</p> <p>Results</p> <p>Thirty-one out of 509 families with multiple cases of PD (6.1%) were found to have 58 <it>LRRK2 </it>mutation carriers (6.4%). Twenty-nine of the 31 families had G2019S mutations while two had R1441C mutations. No mutations were identified among controls or unaffected relatives of PD cases. Nine PD-affected relatives of G2019S carriers did not carry the <it>LRRK2 </it>mutation themselves. At the maximum observed age range of 90 to 94 years, the unbiased estimated penetrance was 67% for G2019S families, compared with a baseline PD risk of 17% seen in the non-<it>LRRK2</it>-related PD families.</p> <p>Conclusion</p> <p>Lifetime penetrance of <it>LRRK2 </it>estimated in the unascertained relatives of multiplex PD families is greater than that reported in studies of sporadically ascertained <it>LRRK2 </it>cases, suggesting that inherited susceptibility factors may modify the penetrance of <it>LRRK2 </it>mutations. In addition, the presence of nine PD phenocopies in the <it>LRRK2 </it>families suggests that these susceptibility factors may also increase the risk of non-<it>LRRK2</it>-related PD. No differences in penetrance were found between men and women, suggesting that the factors that influence penetrance for <it>LRRK2 </it>carriers are independent of the factors which increase PD prevalence in men.</p

Associated features in females with an FMR1 premutation

Abstract Changes in the fragile X mental retardation 1 gene (FMR1) have been associated with specific phenotypes, most specifically those of fragile X syndrome (FXS), fragile X tremor/ataxia syndrome (FXTAS), and fragile X primary ovarian insufficiency (FXPOI). Evidence of increased risk for additional medical, psychiatric, and cognitive features and conditions is now known to exist for individuals with a premutation, although some features have been more thoroughly studied than others. This review highlights the literature on medical, reproductive, cognitive, and psychiatric features, primarily in females, that have been suggested to be associated with changes in the FMR1 gene. Based on this review, each feature is evaluated with regard to the strength of evidence of association with the premutation. Areas of need for additional focused research and possible intervention strategies are suggested

Investigation and modelling of diesel particulate filters

Available from British Library Document Supply Centre- DSC:DXN060038 / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

The effect of boost pressure on the performance characteristics of a diesel engine: A neuro-fuzzy approach

This paper uses a neuro-fuzzy interface system (ANFIS) to study the effect of boost pressure on the efficiency, brake mean effective pressure (BMEP), and the brake specific fuel consumption (BSFC) of a single cylinder diesel engine. Experimental data were used as inputs to ANFIS to simulate the engine performance characteristics. The experimental as well as the model results emphasize the role of boost pressure in improving the different engine characteristics. The results show that the ANFIS technique can be used adequately to identify the effect of boost pressure on the different engine characteristics. In addition, different data points that were not used for ANFIS training were used to validate the developed models. The results suggest that ANFIS can be used accurately to predict the effect of boost pressure on the different engine characteristics.Boost pressure Diesel engine Neuro-fuzzy ANFIS