A study of fermentation heterogeneity in a pilot scale airlift bioreactor

The extent of the heterogeneity in a large scale vessel can affect cell growth and product yields. Consequently, the examination of the impact of the engineering environment on the physiology of fermentation broths can lead to improved growth and production conditions which will be important for fermentation optimisation including scale up, design and operation of bioreactors. Bioreactor heterogeneity has been studied in a multiconfigurable pilot scale airlift reactor (0.25 m3) which can create different degrees of heterogeneity. Hydrodynamic and oxygen transfer performances of two air ring sparger configurations, ie. in the annulus or draft tube, in combination with a marine propeller fitted at the base of the reactor, were compared using Newtonian baker's yeast suspensions and batch cultures of non-Newtonian Saccharopolyspora erythraea. The cellular growth, morphology and productivity of the S. erythraea broths were also compared between the airlift reactor configurations and stirred tank. The comparison of gas holdup, liquid velocity and mixing times between the two sparger configurations with baker's yeast suspension was influenced by the ratio of the cross sectional area of the downcomer to the riser and the bubble flow regime. The achievement of a critical liquid height above the draft tube for optimal liquid mixing demonstrated the importance of the top section to the liquid mixing performance of the vessel. The local DOT and kLa values were greater in the downcomer than in the riser. This was caused by the high gas content, long gas residence times and smaller bubble diameter in the downcomer compared to the riser. The gas holdup, liquid circulation and oxygen transfer with conventional airlift operation were improved by operating the marine propeller in conjunction with the annulus ring sparger to draw liquid down the draft tube. This led to a reduction in the extreme DOT heterogeneity and a increase of the OUR of the yeast suspension. Maximum OUR was obtained when the lowest DOT of the cycling DOT was at or above 10% (air saturation). The OUR improved if the cells experienced the same DOT changes at a greater frequency. This indicated that cells could respond to rapid DOT changes around the vessel and so the cell metabolism was not based on an average DOT of the vessel. During the S. erythraea fermentations the enhancement of bubble coalescence with increasing apparent viscosity led to the reduction of the sectional gas holdups and local kLa values and the improvement of liquid mixing. The extent of the changes with increasing apparent viscosity were dependent on the broth morphology, reactor configurations and operating conditions. The relationships between broth rheology and the dry cell weight, morphology and liquid velocity were all influenced by the reactor configuration and operating conditions. DOT heterogeneity did not affect the growth of mycelial S. erythraea broths but the reduction of DOT heterogeneity improved the specific erythromycin production rate and final specific erythromycin production which was proportional to the energy dissipation rate. The study shows that an understanding of cell physiology and the effect of the engineering environment on their growth, productivity and morphology is essential for the enhancement of bioprocesses. The examination of reactor heterogeneity provides a better understanding of the effects of the translation of scale and as a result can lead to a more efficient process with improved productivity

Habits in action: a corrective to the neglect of habits in contemporary philosophy of action

I propose that if we pay proper attention to habits, we can correct distortions in prevailing accounts of action, and make progress in a number of contemporary debates. First I describe the everyday phenomenon of habit, and sketch the context as we find it within contemporary analytic philosophy. I then develop a notion of habit which has its origins in Wittgenstein, Ryle and Aristotie. The generic notion upon which all three thinkers draw is that of a kind of behaviour which is repeated; automatic, in the sense that it does not involve deliberation or trying; and responsible, since it is under the agent's control. I call such behaviour habitual action. Third, I reject the widely held view that the class of rational actions and the class of actions which we perform "for reasons" are equivalent. This view, made popular by Davidson, distorts our conception of rational actions by taking deliberated actions to be the sole paradigm. I suggest that this is an "intellectualist" error, which gives too prominent a place to our deliberative capacity in our picture of rational actions. 1 argue, against this, that on many of the occasions that we act habitually, we do not act for reasons, although we do act rationally, in ways that 1 spell out. Fourth and finally I outline how broadening our conception of rational actions to include many of those we perform habitually allows us to make progress in contemporary debates. I focus on the debate in meta-ethics between Humean (Smith, Blackburn) and anti-Fiumean (McDowell) accounts of moral motivation. I argue that properly understood, habits form a crucial part of the anti-Flumean argument - one which has hitherto been obscure in McDowell. I suggest other debates to which an understanding of habits could contribute, such as the project of "naturalising" rational action

The opponents of Paul at Corinth

Thesis (Ph.D.)--Boston University This item was digitized by the Internet Archive

The self-consciousness of Jesus

This item was digitized by the Internet Archive. Thesis (M.A.)--Boston Universityhttps://archive.org/details/theselfconscious00pol

Strategic Data Mining and Database Development for Research Projects at Lake Mead, Nevada-Arizona USA

“Water 2025” is a Department of Interior initiative designed to guide the management of scarce water resources in the American West. As an important Colorado River reservoir, Lake Mead is a fundamental component of Water 2025. For Water 2025 to achieve its goals, comprehensive knowledge is needed of historic and current Lake Mead water quality data. A task agreement between the National Park Service and the University of Nevada, Las Vegas provides for a strategic data mining project to identify research and monitoring projects on Lake Mead that have been conducted in the past, prioritize relevant projects, and ensure data availability by converting the data to an electronic format. During the first phase of the project a comprehensive literature search was conducted to discover research projects focused on Lake Mead, particularly those focused on the topics of water quality, limnology, contaminants, fisheries, aquatic biota, and riparian/shoreline resources. A relational database was created using Microsoft Access to serve as a repository for descriptive data for Lake Mead research projects. Data is structured to allow multi-field searches for project results with sub-headings such as: research topics, research locations, parameters measured, and date or duration of research. A ranking system allows for prioritization of data mining activities and the capture of electronic data during the project’s second phase. The ultimate goal of this project is to make historic data more available to the managers and researchers working towards meeting the goals of Water 2025

Harmonising topographic & remotely sensed datasets, a reference dataset for shoreline and beach change analysis.

This paper presents a novel reference dataset for North Norfolk, UK, that demonstrates the value of harmonising coastal field-based topographic and remotely sensed datasets at local scales. It is hoped that this reference dataset and the associated methodologies will facilitate the use of topographic and remotely sensed coastal datasets, as demonstrated here using open-access UK Environment Agency datasets. Two core methodologies, used to generate the novel reference dataset, are presented. Firstly, we establish a robust approach to extracting shorelines from vertical aerial photography, validated against LiDAR (Light Detection and Ranging) and coastal topography surveys. Secondly, we present a standard methodology for quantifying sediment volume change from spatially continuous LiDAR elevation datasets. As coastal systems are monitored at greater spatial resolution and temporal frequency there is an unprecedented opportunity to determine how and why coastal systems have changed in the past with a view to informing future forecasting. With revelation of trends that suggest increasing coastal risk, coastal change research is needed to inform the management and protection of coasts

Waste to want: polymer nanocomposites using nanoclays extracted from oil based drilling mud waste.

Due to the European Union (EU) waste frame work directive (WFD), legislations have been endorsed in EU member states such as UK for the Recycling of wastes with a vision to prevent and reduce landfilling of waste. Spent oil based drilling mud (drilling fluid) is a waste from the Oil and Gas industry with great potentials for recycling after appropriate clean-up and treatment processes. This research is the novel application of nanoclays extracted from spent oil based drilling mud (drilling fluid) clean-up as nanofiller in the manufacture of nanocomposite materials. Research and initial experiments have been undertaken which investigate the suitability of Polyamide 6 (PA6) as potential polymer of interest. SEM and EDAX were used to ascertain morphological and elemental characteristics of the nanofiller. ICPOES has been used to ascertain the metal concentration of the untreated nanofiller to be treated (by oil and heavy metal extraction) before the production of nanocomposite materials. The challenges faced and future works are also discussed

A Legal Framework for Regulating Autonomous Weapon System Deployments

The principle aim of this research is the creation of a unique legal framework to regulate the use of the emerging technology referred to as Autonomous Weapons Systems (AWS). To date, the formulation of such a framework has not been possible due primarily to the abject lack of certainty as to what an AWS is. Despite this, AWS are particularly controversial primarily because in order for them to operate humankind must delegate battlefield life-or-death decision making responsibilities to machines. In 2019, amidst increasing calls for absolute prohibition to be placed upon their use, a group of governmental experts (GGE), assembled by the United Nations (UN), did endorse a set of (non binding) “guiding principles”. These were intended to help shape future weapons development. However, they are woefully superficial, and notably muted as to exactly what types of weapons they should be applied to. This thesis seeks to compensate for the existing lacunae in several novel ways. First, it develops an unparalleled, multi-dimensional, definitional tool. This is referred to throughout as the Template. Unconventionally, the Template allows for individual classification based first, according to a weapons type, second to the matter of whether the AWS is to be deployed defensively or offensively, and third in regard of whether an AWS is to apply a lethal, or non-lethal force (noting the latter two axes represent a particularly contentious element of the existing discussion). It is only by consulting the Template that the researcher is able undertake the second thesis aim, which is the realisation of an unrivalled, comprehensive, and independent analysis as to the lawfulness of AWS deployments – doing so according to the jus ad bellum, the jus in bello, and international human rights law. From these separate, though inextricably intertwined examinations, various rules are distilled. These are significantly dissimilar to any such rules which have preceded them, not least because each is grounded, or in some other way related to, an existing legal obligation. In closing, the researcher presents these rules holistically as set guiding principles which efficaciously provide the absent legal framework for regulating individual AWS deployments. Ultimately, this body of research unequivocally supports the researcher’s hypothesis that AWS are not inherently unlawful. However, by endorsing the guiding principles, states can greatly restrict or eliminate many of the inherent dangers of utilizing this revolution in military affairs, while still harnessing many of their advantages