121 research outputs found

    Sintering Characteristics of Lignite Ash

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    The relationship of the sintering characteristics of lignite ash to the known fouling tendency of the ash was investigated. The investigation includes the determination of the temperature at which sintering begins and the correlation of fouling tendency of the ash to the compressive strength developed during the sintering of ash specimens. The significance of sample preparation, sodium content, and treatment temperature was determined by statistical analysis of the data. The temperature at which sintering begins was determined for samples of ash prepared in the laboratory. Differences in this sinter temperature were observed for samples with different fouling tendencies. The sinter point could not be determined for samples of ash which had been prepared by other methods from the same coal. Compressive strengths developed during sintering were very similar for samples of high-sodium content fly ash and high-sodium content laboratory ash. The sinter strengths of the low-sodium counter-parts of these two ashes were also very similar. The differences in sinter strength developed for the high- and low-sodium content samples of each type of ash also gives a clear indication of the relative fouling tendency. An analysis of the variance of the sinter strength data indicates that sodium level, sample preparation method and treatment temperature all have a significant effect on the sinter strength. The relative fouling tendency of lignite ash can be measured using samples of ash prepared is the laboratory, by wither determining the sinter point or the sinter strength developed

    Philosophy and ethics of de-extinction

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    In this essay, we explore the philosophical and ethical issues concerning de-extinction. First, we will characterize what de-extinction is. This requires clarification of the process of extinction. Second, we consider whether de-extinction is even possible. There are a variety of arguments involving the nature of species that purport to show that once they have disappeared they cannot be resurrected. Third, we examine whether de-extinction is morally permissible. There are arguments that suggest we are obligated to do it based on restorative justice and biodiversity conservation. There are other arguments that conclude we are not permitted to do so based on considerations of animal welfare, hubris and the allocation of conservation resources

    It's just a feeling: why economic models do not explain

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    Julian Reiss correctly identified a trilemma about economic models: we cannot maintain that they are false, but nevertheless explain and that only true accounts explain. In this reply we give reasons to reject the second premise – that economic models explain. Intuitions to the contrary should be distrusted

    Neo-Aristotelian Naturalism and the Evolutionary Objection: Rethinking the Relevance of Empirical Science

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    Neo-Aristotelian metaethical naturalism is a modern attempt at naturalizing ethics using ideas from Aristotle’s teleological metaphysics. Proponents of this view argue that moral virtue in human beings is an instance of natural goodness, a kind of goodness supposedly also found in the realm of non-human living things. Many critics question whether neo-Aristotelian naturalism is tenable in light of modern evolutionary biology. Two influential lines of objection have appealed to an evolutionary understanding of human nature and natural teleology to argue against this view. In this paper, I offer a reconstruction of these two seemingly different lines of objection as raising instances of the same dilemma, giving neo-Aristotelians a choice between contradicting our considered moral judgment and abandoning metaethical naturalism. I argue that resolving the dilemma requires showing a particular kind of continuity between the norms of moral virtue and norms that are necessary for understanding non-human living things. I also argue that in order to show such a continuity, neo-Aristotelians need to revise the relationship they adopt with empirical science and acknowledge that the latter is relevant to assessing their central commitments regarding living things. Finally, I argue that to move this debate forward, both neo-Aristotelians and their critics should pay attention to recent work on the concept of organism in evolutionary and developmental biology

    An Integrated Framework for Process-Driven Model Construction in Disease Ecology and Animal Health

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    Process models that focus on explicitly representing biological mechanisms are increasingly important in disease ecology and animal health research. However, the large number of process modelling approaches makes it difficult to decide which is most appropriate for a given disease system and research question. Here, we discuss different motivations for using process models and present an integrated conceptual analysis that can be used to guide the construction of infectious disease process models and comparisons between them. Our presentation complements existing work by clarifying the major differences between modelling approaches and their relationship with the biological characteristics of the epidemiological system. We first discuss distinct motivations for using process models in epidemiological research, identifying the key steps in model design and use associated with each. We then present a conceptual framework for guiding model construction and comparison, organised according to key aspects of epidemiological systems. Specifically, we discuss the number and type of disease states, whether to focus on individual hosts (e.g. cows) or groups of hosts (e.g. herds or farms), how space or host connectivity affect disease transmission, whether demographic and epidemiological processes are periodic or can occur at any time, and the extent to which stochasticity is important. We use foot-and-mouth disease and bovine Tuberculosis in cattle to illustrate our discussion and support explanations of cases in which different models are used to address similar problems. The framework should help those constructing models to structure their approach to modelling decisions and facilitate comparisons between models in the literature

    Analytic philosophy for biomedical research: the imperative of applying yesterday's timeless messages to today's impasses

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    The mantra that "the best way to predict the future is to invent it" (attributed to the computer scientist Alan Kay) exemplifies some of the expectations from the technical and innovative sides of biomedical research at present. However, for technical advancements to make real impacts both on patient health and genuine scientific understanding, quite a number of lingering challenges facing the entire spectrum from protein biology all the way to randomized controlled trials should start to be overcome. The proposal in this chapter is that philosophy is essential in this process. By reviewing select examples from the history of science and philosophy, disciplines which were indistinguishable until the mid-nineteenth century, I argue that progress toward the many impasses in biomedicine can be achieved by emphasizing theoretical work (in the true sense of the word 'theory') as a vital foundation for experimental biology. Furthermore, a philosophical biology program that could provide a framework for theoretical investigations is outlined
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