A Tropical Modern Architect: Prof. John Owusu Addo

Professor John Owusu Addo is a Ghanaian tropical modern architect and a pioneer in architectural education and practice in the nation-building of Ghana and other Commonwealth countries. His contributions to the modern architecture discourse seem to be overshadowed by the cohort of architects of both Western and Socialist origin who practiced in Africa during the decolonization era. The Community Center at the Kwame Nkrumah University of Science and Technology (KNUST) campus in Kumasi-Ghana was designed by him; it represents a classic example of ‘unknown’ heritage within the narrative. This short essay examines both primary and secondary data, including unpublished interviews, master series events, articles, and papers to contextualize Prof. Owusu Addo as an exemplary protagonist to be explored for the benefit of tropical modern architects, especially in African settings

Photo-assisted Flow Battery Charging

The rapid increase in renewable energy in our electrical grid has driven the need for energy storage systems to mitigate the effects of intermittent renewable sources. The coupling of renewable energy sources such as photovoltaics with batteries can lead to space and efficiency losses due to the interconnection of the two systems through wiring. A potential method for conjoining solar energy generation with energy storage is through a technology known as solar flow batteries. These batteries utilize dye-sensitized solar cells to aid in the charging process of the battery. In this project a methodology for fabricating working photoanodes for usage in a solar flow battery is laid out in detail. Photoanodes are fabricated and tested through polarization testing and SEM imaging to determine the electrical and surface properties respectively. Photoanode samples with a maximum power output of ~0.1 mW/cm2 are shown but also demonstrate highly unideal solar cell performance through fill factor values ranging from 30-40%. Further work is then laid out on avenues to explore in detail to address the low performance values of photoanodes fabricated through the process detailed.http://deepblue.lib.umich.edu/bitstream/2027.42/169566/1/wesf_HonorsCapstone.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/169566/2/HonorsCapstonePresentation.pptxhttp://deepblue.lib.umich.edu/bitstream/2027.42/169566/3/CapstonePresentationVideo_WesFermanich.mp

Electrochemical studies of lithium-oxygen reactions for lithium-air battery applications

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (p. 61-63).Fundamentally understanding reaction mechanisms during Li-O₂ cell operation is critical for implementing Li-air batteries with high reversibility and long cycle life. In this thesis, the rotating ring disk electrode (RRDE) technique has been used to probe the influence of different electrolyte solvents on the stability of the superoxide radical produced on planar glassy carbon and Au electrodes. It was found that the fraction of oxygen reduction reaction current attributable to superoxide generation exhibits a solvent-invariant potential dependence on carbon, with a higher fraction of superoxide produced at lower discharge overpotentials. This trend is in support of a proposed growth model for different Li-O₂ morphologies, where Li-O₂ growth is governed primarily by disproportionation of superoxide at low overpotentials and direct electron transfer at high overpotentials. On Au, superoxide stability exhibits a strong solvent dependence, which can be explained in terms of the effect of the electrolyte solvent basicity on the stability of the Li+-O₂- ion pair. This study highlights the potential use of RRDE as a tool to gain insights into Li-O₂ reaction and growth mechanisms and the contribution of soluble intermediate species to parasitic reactions in practical Li-air batteries.by David G. Kwabi.S.M

The impact of stringent insider trading laws and institutional quality on cost of capital

This paper examines the effects of interaction between stringent insider trading laws, institutional quality and equity portfolio allocation on the cost of capital. Using a dataset drawn from 44 countries over the period from 2001 to 2015, we find that stringent insider trading laws interact with institutional quality and foreign equity portfolio allocation to reduce the country-level cost of capital. Further analysis from a quasi-natural experiment based on the 2008–2009 global financial crisis suggests that the findings are robust to endogeneity. Our results imply that the enactment of stringent insider trading laws and their interplay with the quality of institutions are not only important to portfolio investment allocation decisions but reduce the country-level cost of capital

Cre-loxP mediated genoinic targeting to develop rapid and reproducible expression of recombinant proteins in mammalian cells.

PhDExpression levels of transgenes in mammalian cells show extreme variability between individual clones isolated from a single transfection. This is due to differing number of copies integrated into the genome and also from chromosomal "position effects". Therefore extensive screening is required to isolate a suitable cell line for high level expression of a recombinant protein. In this work, the Cre-loxP site-specific recombination system was investigated to eliminate such problems by directing the rapid targeting of any input DNA to a single pre-selected site in Chinese hamster ovary (CHO) cell line. Cre is a 38 kDa recombinase encoded by the bacteriophage P1 which mediates recombination between a pair of specific 34 bp target sequencesc alled loxP sites. The recombination reaction was first investigated in vitro to establish which kinetic parameters could be relevant for efficient gene targeting: a recombinant baculovirus was constructed with a hexa-histidine-cre fusion gene. The activity of Cre protein purified (by single step, hexa-histidine/nickel-bindinga, ffinity chromatography) from infected insect cells was verified by: (i) Cre-loxP interaction in gel retardation assays and (ii) Cre-mediated intramolecular excision between two loxP sites flanking a lacZ gene in a plasmid DNA. To investigate Cre-mediated targeting of an exogenous DNA to a chromosomal loxP site, three CHO cell lines were constructed, each carrying a loxP site between a ß-actin promoter and a secreted alkaline phosphatase (SAP) gene as a reporter. To demonstrate the targeting event, a promoterless lacZ/neor gene was cotransfected with either a cre plasmid or the purified Cre protein from the baculovirus/insect system. Proper targeting should activate expression of f 3- galactosidase from the chromosomal 0-actin promoter and give loss or reduction of SAP expression in G418 resistant transformants. Southern blot analysis showed targeted events mediated by both cre plasmid and recombinant Cre protein. This work should allow the development of a generic mammalian cell line by incorporating the Cre-loxP system for rapid and reproducible large scale production of recombinant proteins.Medical Research Council The Wellcome Foundation Limited post-graduate CASE studentship

Agricultural productivity and supply responses in Ghana

The importance of Agricultural Supply Response (ASR) modelling cannot be over emphasised. Knowledge of its size provides a roadmap for designing a tailored agricultural policy based on suppliers’ responses to price and non-price incentives. In spite of its policy importance, limited amount of studies exist for Ghana. This study seeks to fill the gap and also sheds some light on how future agricultural policies in Ghana should be formulated. This study is conducted on a regional (ecological) group basis and at a crop-level. Apart from price and non-price factors, we have also accounted for technical inefficiencies, a problem that impedes the growth of agricultural production in Ghana. We employed the duality modelling technique (based on the profit function). This technique provides a more intuitive way of modelling and interpreting ASRs. We used the fourth wave of the Ghana Living Standard Survey (GLSS4), a cross-sectional dataset collected between 1998 and 1999. The analysis is based on six crops, grouped into industrial (cocoa and groundnut), food (maize, rice and cowpea) and staple (sorghum and millet combined and termed migso in the study). A sensitivity analysis is carried out to check the robustness of results. We found high national and ecological technical inefficiency scores. Nationally, technical inefficiency is in the neighbourhood of 53%. At the ecological levels, groundnut (industrial crop) farmers in the Coastal zone recording the highest inefficiency (83%) with the least inefficiency score coming from cowpea (food) farmers in the Savannah zone (30%). In a related outcome we found that technical inefficiency estimates and patterns are sensitive to the structure and composition of the dataset. Our supply elasticities support claims that farmers in Ghana will respond to both market (price) and non-price incentives. In terms of price incentives we found that, with or without technical inefficiency, farmers of food crops in the Coastal zone will respond the most to changes to outputs prices. Farmers in the Savannah zone for all crops but staples will be the least to respond to output price change. We found, however, that with production inefficiency accounted for, supply responses were relatively lower, reinforcing the arguments that earlier supply response estimates from other studies could have been inaccurately estimated especially where analysis failed to account for non-price factors. Moreover, the study estimates revealed that farmers in Ghana are would record a larger output supply responses to changes in inputs prices than output prices. Besides price, the study also found that all four non-price incentives - plot size, animal capital, family labour and education of household head - are important to the development of an effective agricultural policy regardless of whether technical inefficiency is accounted for or not. In some cases, output supply responses from non-prices factors outweighed price elasticities, again supporting the argument that ASR estimates are likely to be biased if non-price factors are omitted. These findings provide two policy signposts for the design of Ghana’s future agricultural policies. Firstly, the policy - aimed at increasing output and/or improving the sector’s competitiveness - must identify and address technical inefficiencies among smallholder agricultural farmers. Failure to address such inefficiencies would lead to suboptimal performance - operating on a lower production frontier. Secondly, the differences in crop-level ecological supply elasticities support regional-based agricultural policies rather than a one-size-fits all centralised agricultural policy

International equity portfolio allocations and stock market development

This paper examines whether the widely reported phenomena of home and foreign biases (i.e. sub-optimal international equity portfolio diversification) hold any ramifications for the development of stock markets. The results, analysed using macro- and micro-level data, support the view that stock markets that are characterised by a higher degree of home bias are associated with lower levels of development. On the other hand, markets where foreign investors show a higher degree of allocation preference, relative to the prescribed benchmark (foreign bias), are found to be more developed. The results, which are robust to the use of shock based identification strategy, indicate that policy measures that promote optimal international equity portfolio diversification could be crucial in developing the depth and breadth of domestic stock markets

Agricultural productivity and supply responses in Ghana

The importance of Agricultural Supply Response (ASR) modelling cannot be over emphasised. Knowledge of its size provides a roadmap for designing a tailored agricultural policy based on suppliers’ responses to price and non-price incentives. In spite of its policy importance, limited amount of studies exist for Ghana. This study seeks to fill the gap and also sheds some light on how future agricultural policies in Ghana should be formulated. This study is conducted on a regional (ecological) group basis and at a crop-level. Apart from price and non-price factors, we have also accounted for technical inefficiencies, a problem that impedes the growth of agricultural production in Ghana. We employed the duality modelling technique (based on the profit function). This technique provides a more intuitive way of modelling and interpreting ASRs. We used the fourth wave of the Ghana Living Standard Survey (GLSS4), a cross-sectional dataset collected between 1998 and 1999. The analysis is based on six crops, grouped into industrial (cocoa and groundnut), food (maize, rice and cowpea) and staple (sorghum and millet combined and termed migso in the study). A sensitivity analysis is carried out to check the robustness of results. We found high national and ecological technical inefficiency scores. Nationally, technical inefficiency is in the neighbourhood of 53%. At the ecological levels, groundnut (industrial crop) farmers in the Coastal zone recording the highest inefficiency (83%) with the least inefficiency score coming from cowpea (food) farmers in the Savannah zone (30%). In a related outcome we found that technical inefficiency estimates and patterns are sensitive to the structure and composition of the dataset. Our supply elasticities support claims that farmers in Ghana will respond to both market (price) and non-price incentives. In terms of price incentives we found that, with or without technical inefficiency, farmers of food crops in the Coastal zone will respond the most to changes to outputs prices. Farmers in the Savannah zone for all crops but staples will be the least to respond to output price change. We found, however, that with production inefficiency accounted for, supply responses were relatively lower, reinforcing the arguments that earlier supply response estimates from other studies could have been inaccurately estimated especially where analysis failed to account for non-price factors. Moreover, the study estimates revealed that farmers in Ghana are would record a larger output supply responses to changes in inputs prices than output prices. Besides price, the study also found that all four non-price incentives - plot size, animal capital, family labour and education of household head - are important to the development of an effective agricultural policy regardless of whether technical inefficiency is accounted for or not. In some cases, output supply responses from non-prices factors outweighed price elasticities, again supporting the argument that ASR estimates are likely to be biased if non-price factors are omitted. These findings provide two policy signposts for the design of Ghana’s future agricultural policies. Firstly, the policy - aimed at increasing output and/or improving the sector’s competitiveness - must identify and address technical inefficiencies among smallholder agricultural farmers. Failure to address such inefficiencies would lead to suboptimal performance - operating on a lower production frontier. Secondly, the differences in crop-level ecological supply elasticities support regional-based agricultural policies rather than a one-size-fits all centralised agricultural policy

High frequency trading, price discovery and market efficiency in the FTSE100

The file attached to this record is the author's final peer reviewed version.This study examines the role of high frequency trading in price discovery and efficiency in the FTSE100 index tick changes. Using a unique data set, we find that there is no random walk when investors extract information at a millisecond to a second. Further analysis provides evidence that the information cannot be extracted by investors at frequencies starting from 10 minutes. This is consistent with the view that the market already experiences a random walk, which contributes to the weak form of market efficiency

Corporate carbon emissions and market valuation of organic and inorganic investments

We empirically examine the impact of a firm’s carbon emissions level on the market valuation of organic and inorganic investments. We document that the market reacts negatively to corporate investment announcements by companies with high carbon emissions levels. Further analysis indicates that the discount on market valuation is more pronounced for the set of organic investments, within which only asset acquisitions and product launches are negatively affected by the high carbon emissions level at the announcement