ADHD & Eating Pathology: Is there an association between ADHD & eating disorders?

This dissertation will examine the association between ADHD & eating pathology, a link that has gone unnoticed for decades. Many females tend to internalise ADHD symptoms, most commonly reported in the form of depression, anxiety, and mood disorders; however, the literature review will provide evidence that suggests the development of an eating disorder may be the result of internalising ADHD symptoms. This dissertation will take the form of an autoethnography combined with an extended, critical literature review. I will be reflecting on my personal experience with comorbid ADHD & bulimia nervosa to support claims made in the literature. The relationship between ADHD and multiple forms of eating pathology, including bulimia nervosa, anorexia nervosa, and binge eating disorder will all be examined, as well as the relationship between ADHD and obesity and certain nutritional factors that contribute to ADHD. The literature review will provide evidence that there is a direct association between ADHD & bulimia and binge eating disorder. Possible treatment options, including medication for individuals suffering with comorbid ADHD & an eating disorder will be discussed along with other implications for practice

A spectroscopy study of gasoline partially premixed compression ignition spark assisted combustion

Nowadays many research efforts are focused on the study and development of new combustion modes, mainly based on the use of locally lean air–fuel mixtures. This characteristic, combined with exhaust gas recirculation, provides low combustion temperatures that reduces pollutant formation and increases efficiency. However these combustion concepts have some drawbacks, related to combustion phasing control, which must be overcome. In this way, the use of a spark plug has shown to be a good solution to improve phasing control in combination with lean low temperature combustion. Its performance is well reported on bibliography, however phenomena involving the combustion process are not completely described. The aim of the present work is to develop a detailed description of the spark assisted compression ignition mode by means of application of UV–Visible spectrometry, in order to improve insight on the combustion process. Tests have been performed in an optical engine by means of broadband radiation imaging and emission spectrometry. The engine hardware is typical of a compression ignition passenger car application. Gasoline was used as the fuel due to its low reactivity. Combining broadband luminosity images with pressure-derived heat-release rate and UV–Visible spectra, it was possible to identify different stages of the combustion reaction. After the spark discharge, a first flame kernel appears and starts growing as a premixed flame front, characterized by a low and constant heat-release rate in combination with the presence of remarkable OH radical radiation. Heat release increases temperature and pressure inside the combustion chamber, which causes the auto-ignition of the rest of the unburned mixture. This second stage is characterized by a more pronounced rate of heat release and a faster propagation of the reactions through the combustion chamber. Moreover, the measured UV–Visible spectra show some differences in comparison with the other stages. The relative intensities in of spectra from different combustion radicals have also been related to the different combustion phases.The authors acknowledge that part of this work was performed in the frame of Project DUFUEL TRA2011-26359, funded by the Spanish Government. The authors also thank GM for technical assistance and its support in other parts of this work.Pastor Soriano, JV.; García Oliver, JM.; García Martínez, A.; Micó Reche, C.; Durret, R. (2013). A spectroscopy study of gasoline partially premixed compression ignition spark assisted combustion. Applied Energy. 104:568-575. https://doi.org/10.1016/j.apenergy.2012.11.030S56857510

Exploring Hydrogen–Diesel Dual Fuel Combustion in a Light-Duty Engine: A Numerical Investigation

Dual fuel combustion has gained attention as a cost-effective solution for reducing the pollutant emissions of internal combustion engines. The typical approach is combining a conventional high-reactivity fossil fuel (diesel fuel) with a sustainable low-reactivity fuel, such as bio-methane, ethanol, or green hydrogen. The last one is particularly interesting, as in theory it produces only water and NOx when it burns. However, integrating hydrogen into stock diesel engines is far from trivial due to a number of theoretical and practical challenges, mainly related to the control of combustion at different loads and speeds. The use of 3D-CFD simulation, supported by experimental data, appears to be the most effective way to address these issues. This study investigates the hydrogen-diesel dual fuel concept implemented with minimum modifications in a light-duty diesel engine (2.8 L, 4-cylinder, direct injection with common rail), considering two operating points representing typical partial and full load conditions for a light commercial vehicle or an industrial engine. The numerical analysis explores the effects of progressively replacing diesel fuel with hydrogen, up to 80% of the total energy input. The goal is to assess how this substitution affects engine performance and combustion characteristics. The results show that a moderate hydrogen substitution improves brake thermal efficiency, while higher substitution rates present quite a severe challenge. To address these issues, the diesel fuel injection strategy is optimized under dual fuel operation. The research findings are promising, but they also indicate that further investigations are needed at high hydrogen substitution rates in order to exploit the potential of the concept

Application of UV Visible Light Absorption and Scattering technique to low absorption fuels under diesel-like conditions

Light Absorption and Scattering technique (LAS) has been applied for the measurement of fuel vapour distribution in diesel-type sprays. This technique is usually limited to fuels with relatively high absorptivity, which are sometimes not commonly used as surrogate fuels. In the present paper, a comparison of fuels with very different absorptive properties has been made to determine the range of application of the methodology. A calibration procedure has been applied to n-decane (DEC), a binary blend of n-decane and n-hexadecane (50DEC) and three blends of n-heptane with a highly-absorpting fuel (HEPB1, HEPB2 and HEPB3). This methodology enables the in-situ quantification of absorption coefficients at high pressure and temperature by creating a uniform mixture inside the cylinder. Results have been later applied for the quantification of fuel vapour distribution in sprays for DEC, 50DEC and HEPB3. Results obtained with these range of fuels have enabled to establish the limit in terms of absorption coefficient needed to get consistent results with the technique.This work was partially funded by the Government of Spain through Project TRA2011-26359 and Grant BES-2012-059721. In addition, the authors acknowledge that some equipment used in this work has been partially supported by FEDER project funds (FEDER-ICTS-2012-06), framed in the operational program of unique scientific and technical infrastructure of the Ministry of Science and Innovation of Spain.Pastor Soriano, JV.; García Oliver, JM.; López, JJ.; Micó Reche, C. (2016). Application of UV Visible Light Absorption and Scattering technique to low absorption fuels under diesel-like conditions. Fuel. 179:258-266. https://doi.org/10.1016/j.fuel.2016.03.080S25826617

Study of the auto-ignition phenomenon of PRFs under HCCI conditions in a RCEM by means of spectroscopy

An investigation of the effects of contour conditions and fuel properties on the auto-ignition and combustion process under HCCI conditions is presented in this study. A parametric variation of initial temperature, intake pressure, compression ratio, oxygen concentration and equivalence ratio has been carried out for Primary Reference Fuels in a Rapid Compression Expansion Machine while applying spectroscopy. The results have also been contrasted with natural chemiluminescence measurements. Additionally, the experiments have been simulated in CHEMKIN and the results derived from the optical techniques have been compared with the results from the chemical kinetics of the process, validating the chemical kinetic mechanism and an additional sub-model of excited OH . Two different scenarios can be seen according to the results from the spectrograph. For very lean or very low-temperature combustions no peak of OH is seen at 310 nm of wavelength, proving that the luminosity came from the CO continuum rather than from the OH . However, for more intense combustions (richer equivalence ratios, higher temperatures or lower EGR rates) spectrography shows a clear peak of OH that has much longer time of life than the corresponding to the CO continuum. The main chemical reaction that causes this two scenarios has been identified as H þ HO2 ) 2OH. The increase of relevance of this reaction at high combustion temperatures causes a higher OH accumulation, which leads to a brighter OH emission. Finally, for low temperature combustions the CO continuum out-shines the OH radiation so the light emitted by this radical cannot be detected by means of natural chemiluminescence. 201The authors would like to thank different members of the LAV team of the ETH-Zurich for their contribution to this work. The authors are grateful to the Universitat Politecnica de Valencia for financing the Ph.D. studies of W. Vera-Tudela (FPI SP1 grant 30/05/2012) and his stay at ETH-Zurich (grant 30/12/2014). Finally, the authors would like to thank the Spanish Ministry of Education for financing the Ph.D. studies of Dario Lopez-Pintor (grant FPU13/02329) and his stay at ETH-Zurich (grant EST14/00626).Desantes Fernández, JM.; García Oliver, JM.; Vera-Tudela-Fajardo, WM.; López Pintor, D.; Schneider, B.; Boulouchos, K. (2016). Study of the auto-ignition phenomenon of PRFs under HCCI conditions in a RCEM by means of spectroscopy. Applied Energy. 179:389-400. https://doi.org/10.1016/j.apenergy.2016.06.134S38940017

ADHD & Eating Pathology: Is there an association between ADHD & eating disorders?

This dissertation will examine the association between ADHD & eating pathology, a link that has gone unnoticed for decades. Many females tend to internalise ADHD symptoms, most commonly reported in the form of depression, anxiety, and mood disorders; however, the literature review will provide evidence that suggests the development of an eating disorder may be the result of internalising ADHD symptoms. This dissertation will take the form of an autoethnography combined with an extended, critical literature review. I will be reflecting on my personal experience with comorbid ADHD & bulimia nervosa to support claims made in the literature. The relationship between ADHD and multiple forms of eating pathology, including bulimia nervosa, anorexia nervosa, and binge eating disorder will all be examined, as well as the relationship between ADHD and obesity and certain nutritional factors that contribute to ADHD. The literature review will provide evidence that there is a direct association between ADHD & bulimia and binge eating disorder. Possible treatment options, including medication for individuals suffering with comorbid ADHD & an eating disorder will be discussed along with other implications for practice