Investigation of renewable, coupled solar-hydrogen fuel generation with thermal management systems suitable for equatorial regions

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Solar Energy and Hydrogen (energy carrier) are possible replacement options for fossil fuel and its associated problems of availability and high prices which are devastating small, developing, oil-importing economies. But a major drawback to the full implementation of solar energy, in particular photovoltaic (PV), is the lowering of conversion efficiency of PV cells due to elevated cell temperatures while in operation. Also, hydrogen as an energy carrier must be produced in gaseous or liquid form before it can be used as fuel; but its‟ present major conversion process produces an abundance of carbon dioxide which is harming the environment through global warming. In search of resolutions to these issues, this research investigated the application of Thermal Management to Photovoltaic (PV) modules in an attempt to reverse the effects of elevated cell temperature. The investigation also examined the effects of coupling the thermally managed PV modules to a proton exchange membrane (PEM) Hydrogen Generator for the production of hydrogen gas in an environmentally friendly and renewable way. The research took place in Kingston, Jamaica. The thermal management involved the application of two cooling systems which are Gravity-Fed Cooling (GFC) and Solar-Powered Adsorption Cooling (SPAC) systems. In both systems Mathematical Models were developed as predictive tools for critical aspects of the systems. The models were validated by the results of experiments. The results of the investigation showed that both cooling systems stopped the cells temperatures from rising, reversed the negative effects on conversion efficiency, and increased the power output of the module by as much as 39%. The results also showed that the thermally managed PV module when coupled to the hydrogen generator impacted positively with an appreciably increase of up to 32% in hydrogen gas production. The results of this work can be applied to the equatorial belt but also to other regions with suitable solar irradiation. The research has contributed to the wider community by the development of practical, environmentally friendly, cost effective Thermal Management Systems that guarantee improvement in photovoltaic power output, by introducing a novel way to use renewable energy that has potential to be used by individual household and/or as cottage industry, and by the development of Mathematical Tools to aid in photovoltaic power systems designs

Aunt Betty : Barn Dance

https://digitalcommons.library.umaine.edu/mmb-ps/2977/thumbnail.jp

Investigation of renewable, coupled solar-hydrogen fuel generation with thermal management systems suitable for equatorial regions

Solar Energy and Hydrogen (energy carrier) are possible replacement options for fossil fuel and its associated problems of availability and high prices which are devastating small, developing, oil-importing economies. But a major drawback to the full implementation of solar energy, in particular photovoltaic (PV), is the lowering of conversion efficiency of PV cells due to elevated cell temperatures while in operation. Also, hydrogen as an energy carrier must be produced in gaseous or liquid form before it can be used as fuel; but its‟ present major conversion process produces an abundance of carbon dioxide which is harming the environment through global warming. In search of resolutions to these issues, this research investigated the application of Thermal Management to Photovoltaic (PV) modules in an attempt to reverse the effects of elevated cell temperature. The investigation also examined the effects of coupling the thermally managed PV modules to a proton exchange membrane (PEM) Hydrogen Generator for the production of hydrogen gas in an environmentally friendly and renewable way. The research took place in Kingston, Jamaica. The thermal management involved the application of two cooling systems which are Gravity-Fed Cooling (GFC) and Solar-Powered Adsorption Cooling (SPAC) systems. In both systems Mathematical Models were developed as predictive tools for critical aspects of the systems. The models were validated by the results of experiments. The results of the investigation showed that both cooling systems stopped the cells temperatures from rising, reversed the negative effects on conversion efficiency, and increased the power output of the module by as much as 39%. The results also showed that the thermally managed PV module when coupled to the hydrogen generator impacted positively with an appreciably increase of up to 32% in hydrogen gas production. The results of this work can be applied to the equatorial belt but also to other regions with suitable solar irradiation. The research has contributed to the wider community by the development of practical, environmentally friendly, cost effective Thermal Management Systems that guarantee improvement in photovoltaic power output, by introducing a novel way to use renewable energy that has potential to be used by individual household and/or as cottage industry, and by the development of Mathematical Tools to aid in photovoltaic power systems designs.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

A Census of the High-Density Molecular Gas in M82

We present a three-pointing study of the molecular gas in the starburst nucleus of M82 based on 190 - 307 GHz spectra obtained with Z-Spec at the Caltech Submillimeter Observatory. We present intensity measurements, detections and upper limits, for 20 transitions, including several new detections of CS, HNC, C2H, H2CO, and CH3CCH lines. We combine our measurements with previously-published measurements at other frequencies for HCN, HNC, CS, C34S, and HCO+ in a multi-species likelihood analysis constraining gas mass, density and temperature, and the species' relative abundances. We find some 1.7 - 2.7 x 10^8 M_sun of gas with n_H2 between 1 - 6 x 10^4 cm^-3 and T > 50 K. While the mass and temperature are comparable to values inferred from mid-J CO transitions, the thermal pressure is a factor of 10 - 20 greater. The molecular interstellar medium is largely fragmented and is subject to ultraviolet irradiation from the star clusters. It is also likely subject to cosmic rays and mechanical energy input from the supernovae, and is warmer on average than the molecular gas in the massive star formation regions in the Milky Way. The typical conditions in the dense gas in M82's central kpc appear unfavorable for further star formation; if any appreciable stellar populations are currently forming, they are likely biased against low mass stars, producing a top-heavy initial mass function.Comment: 15 pages (using emulateapj.cls), 6 figures, Astrophysical Journal, in pres

Referrals for suspected hematologic malignancy: A survey of primary care physicians

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91356/1/23172_ftp.pd

Prison Life, Sociology of: Recent Perspectives from the United Kingdom

Prison life both fascinates and repels. As with many aspects of punishment it attracts the interest of both academics and the general public. In this short and accessible account the principal issues of prison life are presented in a historical context that traces the emergence of focussed academic study of the way people live, and die, in prison. The most influential theoretical perspectives are clearly set out alongside a discussion of their influence on research and analysis in the UK and beyond. Questions of women’s experience and that of black and minority ethnic prisoners are explored before a consideration of post-colonial prison studies is introduced. These studies of prison life beyond the axis of Europe and north America challenge some of the accumulated academic wisdom of Anglo-phone and European studies of prison life, indicating the potential of novel developments to come in an era which, nfortunately, shows no signs of declining to produce more and more prisons

Brilliance of a fire: innocence, experience and the theory of childhood

This essay offers an extensive rehabilitation and reappraisal of the concept of childhood innocence as a means of testing the boundaries of some prevailing constructions of childhood. It excavates in detail some of the lost histories of innocence in order to show that these are more diverse and more complex than established and pejorative assessments of them conventionally suggest. Recovering, in particular, the forgotten pedigree of the Romantic account of the innocence of childhood underlines its depth and furnishes an enriched understanding of its critical role in the coming of mass education - both as a catalyst of social change and as an alternative measure of the child-centeredness of the institutions of public education. Now largely and residually confined to the inheritance of nursery education, the concept of childhood innocence, and the wider Romantic project of which it is an element, can help question the assumptions underpinning modern, competence-centred philosophies of childhood

Irrigation and the Origins of the Southern Moche State on the North Coast of Peru

In this paper, I examine the role that irrigation played in the formation of the Southern Moche state in the Moche Valley, Peru. Specifically, I attempt to test Wittfogel and Steward's hydraulic model, which postulates that in certain arid environments, the managerial requirements of construction and maintenance of irrigation systems played a crucial role in the formation of centralized polities. I formulate and evaluate four hypotheses concerning the role of irrigation systems in the Moche Valley. Those hypotheses are then evaluated using settlement pattern data drawn from two surveys that cover the entire coastal section of the valley and provide information on 910 archaeological sites. Based on those data, I present a sequence of political development for the valley from the formation of the first autonomous village in the Late Preceramic period (2500–1800 B. C.) to the zenith of the Southern Moche state. Evaluation of the four hypotheses indicates that the managerial requirements of irrigation were relatively unimportant; rather, warfare, highland-coastal interaction, and political control of irrigation systems created opportunities for leaders to form a highly centralized, territorially expansive state sometime between A. D. 200 and 700

Detection of an ultra-bright submillimeter galaxy in the Subaru/XMM-Newton Deep Field using AzTEC/ASTE

We report the detection of an extremely bright ($\sim$37 mJy at 1100 $\mu$m and $\sim$91 mJy at 880 $\mu$m) submillimeter galaxy (SMG), AzTEC-ASTE-SXDF1100.001 (hereafter referred to as SXDF1100.001 or Orochi), discovered in 1100 $\mu$m observations of the Subaru/XMM-Newton Deep Field using AzTEC on ASTE. Subsequent CARMA 1300 $\mu$m and SMA 880 $\mu$m observations successfully pinpoint the location of Orochi and suggest that it has two components, one extended (FWHM of $\sim$ 4$^{\prime\prime}$) and one compact (unresolved). Z-Spec on CSO has also been used to obtain a wide band spectrum from 190 to 308 GHz, although no significant emission/absorption lines are found. The derived upper limit to the line-to-continuum flux ratio is 0.1--0.3 (2 $\sigma$) across the Z-Spec band. Based on the analysis of the derived spectral energy distribution from optical to radio wavelengths of possible counterparts near the SMA/CARMA peak position, we suggest that Orochi is a lensed, optically dark SMG lying at $z \sim 3.4$ behind a foreground, optically visible (but red) galaxy at $z \sim 1.4$. The deduced apparent (i.e., no correction for magnification) infrared luminosity ($L_{\rm IR}$) and star formation rate (SFR) are $6 \times 10^{13}$ $L_{\odot}$ and 11000 $M_{\odot}$ yr$^{-1}$, respectively, assuming that the $L_{\rm IR}$ is dominated by star formation. These values suggest that Orochi will consume its gas reservoir within a short time scale ($3 \times 10^{7}$ yr), which is indeed comparable to those in extreme starbursts like the centres of local ULIRGs.Comment: 18 pages, 13 figure