Energetic and exergetic assessment of solar and wind potentials in Europe

International audienceThis paper deals with a physics-based assessment of renewable energy potential in Europe, particularly solar and wind energy sources, using two literature models. A sensibility analysis with the weather data is first done. Actual temperature, pressure, relative humidity, global radiation and wind speed data are employed to develop energy and exergy maps for Europe, based on iso-areas of land-use. These maps are compared with similar existing ones. A good agreement is obtained. A paradoxical result is found for wind exergy efficiency. The yearly average exergy efficiency where wind speed is less than 5 m/s is greater than that where wind speed is greater than 7 m/s. This can be explained by the 'dome' shape of wind exergy efficiency. A solar efficiency map for Europe is also developed to serve as a useful guide for choosing a renewable energy form based on yearly energy production

Investigation of the effects of kinesiophobia level on physical activity and quality of life in university students

Background: Kinesiophobia, which is called activity avoidance, is a condition that may cause university students to stay away from physical activity more. This study aimed to understand how physical activity and quality of life levels of university students with different levels of kinesiophobia are affected.  Methods: Our study included 395 students who were studying at Ankara Medipol University in the 2022-2023 academic year and were accepted to participate in our study. The kinesiophobia, physical activity, and quality of life levels of the students were evaluated with questionnaires. The Demographic Characteristics of Students were analyzed using Chi-Square and Mann-Whitney U tests. Spearman correlation analysis was used for the correlation between the scores of the scales, and Mann-Whitney U was used for comparing physical activity levels and quality of life according to kinesiophobia levels. Statistical significance was set as p<0.05. Results: Among the students who participated in our study, 226 (57.22%) students had high kinesiophobia levels and 169 (42.78%) had low kinesiophobia levels. While 74.3% of people with high kinesiophobia levels were women, 67.5% of participants with low kinesiophobia levels were women. The age and BMI levels of the participants in both groups were similar (p>0.05). In our study, while all parameters of WHOQOL and TKS were correlated with each other, only physical and psychosocial sub-parameters of WHOQOL and IPAQ were correlated (p<0.05). According to the results obtained from the study, the physical activity amount and quality of life scores of the students with lower kinesiophobia levels were found to be higher (p<0.05). Conclusion: As a result, different levels of kinesiophobia in university students can affect the amount of physical activity and quality of life of students. It is essential to keep students away from the vicious circle of kinesiophobia and lack of physical activity and to direct them to physical activities

HT2008-56446 FORMULATION OF FILM THEORY EQUATIONS FOR MODELING OF CONDENSATION OF STEAM-AIR MIXTURES IN A SHELL AND TUBE CONDENSER

ABSTRACT Through development of the fundamental equations of Film Theory, condensation of steam in the presence of air in a horizontal counter-current shell and one-path tube condenser is modeled. The interaction between heat and mass transfer and hydrodynamics in the shell-side is taken into consideration. A comparison between the predictions of the model and a set of experimental data available in the archival literature indicates excellent accuracy of the new formulation. The accuracy of the method is further validated by generating profiles of the temperature and pressure drops of the gas flow through the baffles, at various air leakages. Additionally, the effects of air leakage and upstream cooling water temperature are investigated to determine how they influence the total condensation rate, shell-side gas temperature and pressure drops. The results show that the total condensation rate decreases 5% and 20.5% for an air leakage of 1% and 5%, respectively, compared to the situation of pure vapor. Also, increasing the inlet cooling water temperature from 46

The role of GSTM1 gene polymorphisms in lung cancer development in Turkish population

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Techno-economic Feasibility of Renewable Energy Based Stand-alone Energy System for a Green House: Case Study

As the negative impacts of fossil fuel consumption for power generation become increasingly globally evident—particularly the effects of greenhouse gas (GHG) emissions on climate change—so too does the conversely positive potential of renewable energies to reduce the rate of damaging environmental impacts as energy demand grows. In addition to the clear environmental advantage, stand-alone renewable energy power generation options offer energy security and stability in regions where socio-political issues or geographic location might otherwise pose access limitations on fuel and/or electric grid power, particularly in remote communities. This paper discusses the techno-economic considerations for renewable energy power systems in residential community applications. A case study for a residential house in New Cairo in Egypt compares two different renewable energy systems that meet typical electrical demand for this region. Economic assessment—in terms of system net present cost (NPC) and levelized cost of electricity (LCOE)—provide measures for system performance comparison and optimization. The LCOE for system-I and system-II are found to be $0.359/kWh and$0.373/kWh, respectively

Design and simulation of a lithium-ion battery at large C-rates and varying boundary conditions through heat flux distributions

The final publication is available at Elsevier via https://doi.org/10.1016/j.measurement.2017.11.038 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/In this paper, the heat flux distributions on a prismatic lithium-ion battery at 1C, 2C, 3C and 4C discharge rates under various operating temperatures and boundary conditions (BCs) of 22 °C for air cooling and 5 °C, 15 °C, and 25 °C for water cooling are presented. The goal is to provide significant quantitative data on the thermal behaviour of lithium-ion batteries. In this regard, a battery thermal management system with water cooling is designed and developed for a 20 Ah capacity pouch type lithium-ion battery using dual cold plates. Three heat flux sensors are placed at different locations on the principle surface of the battery: the first near the anode, the second near the cathode, and the third at the mid surface of the body. From these the average and peak heat flux values are obtained and presented in this study. In addition to this, the heat flux and voltage distributions are simulated using the neural network approach with the above mentioned discharge rates and BCs. The present results show that increased discharge rates and decreased operating temperature result in increased heat fluxes at the three locations as experimentally measured. Furthermore, the sensors nearest the electrodes (anode and cathode) measured the heat fluxes (and hence temperatures) higher than the sensors located at the center of the battery surface

Transient electrochemical heat transfer modeling and experimental validation of a large sized LiFePO4/graphite battery

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.ijheatmasstransfer.2017.03.005 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Both measurement and modeling of thermal performance in lithium-ion battery cell are considered crucial as they directly affect the safety. Even though the operation of a lithium-ion battery cell is transient phenomena in most cases, most available thermal models for lithium-ion battery cell predicts only steady-state temperature fields. This paper presents a mathematical model to predict the transient temperature distributions of a large sized 20Ah-LiFePO4 prismatic battery at different C-rates. In this regard, the lithium-ion battery is placed in a vertical position on a stand inside the lab with an ambient air cooling and the battery is discharged under constant current rate of 1C, 2C, 3C, and 4C in order to provide quantitative data regarding thermal behavior of lithium-ion batteries. Additionally, IR images are taken for the same battery cell during discharging. The present model predictions are in very good agreement with the experimental data and also with an IR imaging for temperature profiles. The present results show that the increased C-rates result in increased temperatures on the principle surface of the battery. (C) 2017 Elsevier Ltd. All rights reserved

Experimental and simulated temperature variations in a LiFePO4-20Ah battery during discharge process

The final publication is available at Elsevier via http://dx.doi.org/10.101/j.apenergy.2016.08.008 © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/The present study investigates the impact of various discharge rates on the thermal (temperature and heat generation profiles) and electrical performance of the Li-ion battery for electric vehicles and hybrid electric vehicles. For this, a prismatic Li-ion phosphate (LiFePO4) battery with 20Ah capacity is tested under constant current discharge rates of C/10, C/5, C/2, 1C, 2C, 3C, and 4C and surface temperatures and voltage distributions during both charging and discharging are measured. In addition, IR images were also captured during experiments with a Flir Therma CAM S60 IR camera at various discharge rates and are reported in this study. Furthermore, a thermal model is created and validated for a particular battery using a MATLAB Simulink in terms of temperature, voltage, heat generation, and internal resistance. The results of this study demonstrate that the increased C-rates from C/10 to 4C result in increased temperatures on the principal surface of the battery. Also, at the lower discharge rates (below 1C), the surface temperature remains close to the ambient temperature, but at higher discharge rates (above 1C); the surface temperature quickly increases for all C-rates. The most noteworthy surface temperature distribution is observed to be 58.1°C towards the end of 4C discharge

Uneven temperature and voltage distributions due to rapid discharge rates and different boundary conditions for series-connected LiFePO4 batteries

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.icheatmasstransfer.2016.12.026 © 2017. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper presents the surface temperature and voltage distributions on a prismatic lithium-ion battery pack at 1C, 2C, 3C, and 4C discharge rates and 5°C, 15°C, 25°C, and 35°C boundary conditions (BCs) for water cooling and ~22°C for air cooling methods. It provides quantitative data regarding thermal behaviour of lithium-ion batteries for designing thermal management systems and developing reliable thermal models. In this regard, three large LiFePO4 20Ah capacity, prismatic batteries are connected in series with four cold plates used between cells and eighteen thermocouples are placed at distributed locations on the principle surface of all three cells: the first six for the first cell, the second six for the second cell, and the third six for the third cell, and the average and peak surface temperatures as well as voltage distributions are measured and presented in this study. In addition, the simulated heat generation rate, temperature and voltage distributions are validated with an experimental data for the above mentioned C-rates and BCs. The present study shows that increasing discharge rates and BCs results in increase in the maximum and average surface temperatures at the three locations (near the anode, cathode, and mid surface of the body). The highest value of the average surface temperature is obtained for 4C and 35°C BC (36.36°C) and the lowest value is obtained for 1C and 5°C BC (7.22°C) for water cooling method

Experimental and theoretical investigations of heat generation rates for a water cooled LiFePO4 battery

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.ijheatmasstransfer.2016.05.126 © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Understanding the rate of heat generation in a lithium-ion cell is critical for its safety and performance behavior. This paper presents in situ measurements of the heat generation rate for a prismatic Lithium-ion battery at 1C, 2C, 3C and 4C discharge rates and 5°C, 15°C, 25°C, and 35°C boundary conditions (BCs). For this work, an aluminum-laminated battery consisting of LiFePO4 cathode material with 20Ah capacity was adopted to investigate the variation of the rate of heat generation as a function of the discharge capacity. Ten thermocouples and three heat flux sensors were applied to the battery surface at distributed locations. The results of this study show that the highest rate of heat generation was found to be 91W for 4C discharge rate and 5°C BC while the minimum value was 13W measured at 1C discharge rate and 35°C BC. It was also found that the increase in discharge rate and thus the discharge current caused consistent increase in the heat generation rate for equal depth of discharge points. A model is later developed using the neural network approach and validated. The heat generation rate predicted by the model demonstrates an identical behavior with experimental results