1,721,668 research outputs found
Introduction:The nature and scope of environmental mineralogy
No full textMinerals, as the inorganic solids that comprise the rocks, sediments and soils of the Earth, are an essential part of our environment. So, in a sense, all mineralogy is environmental mineralogy. However, the term environmental has come to be employed (particularly in combination with terms such as science, issue or problem) to refer to those systems at or near the surface of the Earth where the geosphere comes into contact with the hydrosphere, atmosphere and biosphere. This is, of course, the “environment” upon which the human race depends for survival, and which can be subject to disruptions due to human activity, particularly activity associated with the exploitation and utilisation of Earth’s resources. This is the sense in which we use the term environmental in this book. Thus, we consider here those systems containing minerals that constitute the most important or key environments: soils, modern sediments, atmospheric aerosols, and the interior or exterior parts of certain micro- and macro-organisms. Both pure systems and those contaminated as a result of human activity are considered. We also focus on certain specific problems that arise from resource exploitation or utilisation and that involve minerals in some way; either, or both, in creating the problem or ameliorating it. These include problems associated with the waste generated by mining, particularly mining of metals, industrial and domestic wastes, and those wastes produced by the nuclear industry. Particular problems can arise from use of minerals and rocks in buildings and monuments and other cultural artefacts. The relationship between minerals and human health constitutes a special case where the environment includes the human body itself
Plurality voting for enhancing reliability
No full textDue to the ubiquity of electronic systems, they are relied on now more than they ever have been in the past. Since technology trends suggest that the reliability of these systems will continue to be a serious concern, and due to their use in safety critical domains, they must be robust. Modelling the reliability of systems, electronic or otherwise, affords an understanding of how to design them to be more reliable. The perspective is taken that hardware is assumed to be abundant but faulty, and the question of how to combine unreliable components to produce a reliable system using redundancy is addressed. This leads to a model based on plurality voting, in which the mathematical properties of the model are explored in depth. Additionally, many properties of plurality voting itself are explored and proved. The model is deliberately made to be very general and does not assume the availability of much exploitable information. The parameter space is explored freely, allowing for high levels of redundancy and covering any number of states. These properties make plurality voting a more practical choice than other popular voting methods such as majority voting. Plurality voting is a more involved and lesser explored voting mechanism, particularly on the scale applied in this work. It is found that the rate at which the number of error states grows and the entropy of the error distribution are amongst the most important factors in the reliability. An interesting connection is found between Renyi entropy and plurality voting that provides a practical approximation for calculating the reliability of an arbitrary error distribution in the context of the model. A conjecture is made about this connection and it is proved for a special case. Finally, interesting and complex patterns are discovered when plurality voting is applied in a hierarchical structure. The interactions between the reliability and cost characteristics of the structures reveal that hierarchical structures can be optimal in reliability and cost for regions of high reliability, providing reliability boosts for free. A conjecture is made about the general behaviour of the optimal set of structures to this effect
Vaughan, David A. - An inaugural dissertation on cancer
No full textHandwritten inaugural dissertation on cancer by D. A. Vaughan, of Tennessee.Inaugural dissertation; no. 284
A new species of Myxinidocotyle (Monogenea: Acanthocotylidae: Myxinidocotylinae) from captive sixgill hagfish, Eptatretus hexatrema (Chordata: Myxinidae), with amendment of the subfamily diagnosis
No full textVaughan, David B., Christison, Kevin W. (2010): A new species of Myxinidocotyle (Monogenea: Acanthocotylidae: Myxinidocotylinae) from captive sixgill hagfish, Eptatretus hexatrema (Chordata: Myxinidae), with amendment of the subfamily diagnosis. Zootaxa 2650: 47-56, DOI: 10.5281/zenodo.19880
FIGURE 5. Callorhynchocotyle marplatensis. A. Whole mount. B in Towards addressing the current state of confusion within the Hexabothriidae Price, 1942 (1908): Callorhynchocotyle Suriano & Incorvaia, 1982 (Monogenea: Hexabothriidae) re-visited, with the preliminary evaluation of novel parameters for measuring haptoral armature of hexabothriids
No full textFIGURE 5. Callorhynchocotyle marplatensis. A. Whole mount. B. Enlarged anterior section of whole mount. C. Enlarged mid-section of whole mount. Abbreviations: ao, anterior section of ovary; ap, appendix; ci, cirrus; dv, distal portion of vagina; eg, egg; ep, excretory pore; i, intestinal caecum; ivt, indentation of ventral tegument surrounding ovate distal cirrus; ji, junction of caeca posterior to testes; oot, ootype; os, oral sucker; p, pharynx; po, posterior section of ovary; sr, seminal receptacle; t, testes; vas, vas deferens; vd, vitteline duct; vp, vaginal pore; 1–3, sucker-sclerite complexes 1–3. Scale bars = 1000µm.Published as part of Vaughan, David & Christison, Kevin, 2012, Towards addressing the current state of confusion within the Hexabothriidae Price, 1942 (1908): Callorhynchocotyle Suriano & Incorvaia, 1982 (Monogenea: Hexabothriidae) re-visited, with the preliminary evaluation of novel parameters for measuring haptoral armature of hexabothriids, pp. 1-34 in Zootaxa 3229 on page 16, DOI: 10.5281/zenodo.28032
FIGURE 2. Myxinidocotyle eptatreti n in A new species of Myxinidocotyle (Monogenea: Acanthocotylidae: Myxinidocotylinae) from captive sixgill hagfish, Eptatretus hexatrema (Chordata: Myxinidae), with amendment of the subfamily diagnosis
No full textFIGURE 2. Myxinidocotyle eptatreti n. sp. A. Marginal hook. B. Pharynx. C. Male accessory gland reservoirs with ducts. Abbreviations: dar, distal male accessory gland reservoir; du, ducts leading to male accessory gland reservoirs; eg, egg; mct, male copulatory tube; par, proximal male accessory gland reservoir (other abbreviations as for Figure 1). Scale bars: A. 15 μm, B. 100 μm, C. 200 μm.Published as part of Vaughan, David B. & Christison, Kevin W., 2010, A new species of Myxinidocotyle (Monogenea: Acanthocotylidae: Myxinidocotylinae) from captive sixgill hagfish, Eptatretus hexatrema (Chordata: Myxinidae), with amendment of the subfamily diagnosis, pp. 47-56 in Zootaxa 2650 on page 51, DOI: 10.5281/zenodo.19880
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