Manufacturing techniques using dycril

Fluidic elements are manufactured in various ways such as injection moulding, epoxy casting and from photo-sensitive ceramic and plastics. Most of the initial work on elements has been carried out using Dycril because of its ease in processing and the equipment required is fairly cheap and simple. Many companies have then developed satisfactory designs using Dycril and used them as ‘masters' in other production processes. Most users of Dycril have reported that nozzle widths of less than 0.015in cannot be satisfactorily etched from 0.040in thick Dycril. Various methods of etching have been tried at Cranfield and this report outlines some of the difficulties encountered and suggests a standard pattern to be followed from the drawings of the master at ten times full size through to the complete element

Familial Ménière's disease: clinical and genetic aspects

ABSTRACT Background and purpose:Mre's disease is not uncommon, with an incidence in Caucasians of about one in 2000. The incidence peaks in the fifth decade. Cases are usually isolated or sporadic, but in perhaps five per cent other family members are affected. We report here the clinical and genetic characteristics of a comprehensive set of familial Mre's disease cases from the UK.Methods:Forty-six affected families were studied. All cases were diagnosed using the American Academy of Otolaryngolog 8211;Head and Neck Surgery committee on hearing and equilibrium 1995, or more stringent, criteria.Outcomes and results:Autosomal dominant inheritance with reduced penetrance was the most likely mode of inheritance overall. Apparent genetic anticipation was observed, but may also be a result of ascertainment bias given the collection strategy. There was also a slight tendency for cases to result from maternal transmission within the families in this set. The family pedigrees are presented, and the authors have also set up a website at which all the pedigrees may be viewed in greater detai

Drilling system design project 1967: final report of frame design committee

This report outlines the recommendations of the Frame Design Committee for the final design of the machine, each major part of the structure being considered individually in the following sections : 1. Worktables 2. Guide and Slideways 3. Drill Head Support Structure 4. Swarf Disposal and Coolant Supply 5. General Constructio

Historical Gloss and the Separation of Powers

Arguments based on historical practice are a mainstay of debates about the constitutional separation of powers. Surprisingly, however, there has been little sustained academic attention to the proper role of historical practice in this context. The scant existing scholarship is either limited to specific subject areas or focused primarily on judicial doctrine without addressing the use of historical practice in broader conceptual or theoretical terms. To the extent that the issue has been discussed, most accounts of how historical practice should inform the separation of powers require “acquiescence” by the branch of government whose prerogatives the practice implicates, something that is viewed as critical to giving historical practice the force of law. Yet the concept of acquiescence has been treated much too casually in the literature. Claims about acquiescence are typically premised on a Madisonian conception of interbranch competition, pursuant to which Congress and the Executive Branch are each assumed to have the tools and the motivation consistently to guard against encroachments on their authority. It has become apparent from political science scholarship, however, that the Madisonian model does not accurately reflect the dynamics of modern congressional-executive relations. This requires a reexamination of the premises and implications of the idea of institutional acquiescence in particular, and of the role of historical practice more generally. Ultimately, we argue, the problems with the Madisonian model are not fatal to crediting historical practice in interpreting the separation of powers. But they do require more attention to the reasons why such practice is invoked, the extent to which the reasons demand institutional acquiescence, and the precise method by which such acquiescence is identified. To illustrate the importance of each of these questions, we present three case studies of constitutional debates concerning the separation of powers in which practice-based arguments are prominent - war powers, congressional-executive agreements, and removal of executive officers

Vented piston seal prevents fluid leakage between two chambers

To prevent fluid leakage around piston seals separating two fluids under differential pressure, a venting system has been devised. Two methods may be used for venting seals through internal passages to an external low-pressure area, O-ring or split-ring seals

Presidential Power, Historical Practice, and Legal Constraint

The scope of the President’s legal authority is determined in part by historical practice. This Essay aims to better understand how such practice-based law might operate as a constraint on the presidency. Some scholars have suggested that presidential authority has become “unbounded” by law, and is now governed only or primarily by politics. At the same time, there has been growing skepticism about the ability of the familiar political checks on presidential power to work in any systematic or reliable fashion. Skepticism about law’s potential to constrain in this context is heightened by the customary nature of much of what purports to be the law of presidential power, and by the limited availability of judicial review. As the Essay explains, no examination of whether law constrains the President can succeed without careful specification of what constraint entails and how it relates to distinct but related phenomena like genuine disagreement about the content of the law. After attempting such specification, the Essay identifies various internal and external causal mechanisms through which law, including practice-based law, could constrain the President. The Essay explains, among other things, that one way that law might constrain the President is through the simple fact that issues of presidential power are publicly criticized and defended in legal terms. To gain additional traction on the topic, the Essay considers two other areas of debate that pose analogous questions about the constraining effect of law: whether the doctrine of stare decisis (itself a practice-based norm) constrains Supreme Court decision making, and whether international law (including the international law that is based on customary practice) constrains the behavior of nation-states. The Essay concludes by suggesting some avenues of possible empirical research

Valuing New South Wales rivers for use in benefit transfer

The results from seven choice modelling applications designed to value improved river health in New South Wales are reported. These applications were designed to provide value estimates that could be used, through benefit transfer, to value improvements in the health of other rivers within the state. Because of limitations on the number of rivers that could be valued and populations sampled, a pooled model for use in benefit transfer was also estimated. The results indicate that both use and non‐use values were found to exist for all catchments. In addition, value estimates were found to differ across catchments when populations resident within catchments were sampled. However, when populations resident outside catchments were sampled for two of these catchments, value estimates were found to be statistically similar. This indicates the importance of valuing improved river health in specific catchments by sampling populations within catchments. Yet, it also indicates that it is less critical to conduct multiple surveys of residents outside catchments to value improved river health.Resource /Energy Economics and Policy,

Post-metamorphic fluid infiltration into granulites from the Adirondack Mountains, USA

Post-metamorphic effects in the anorthosites of the Adirondacks, New York were described. Calcite-chlorite-sericite assemblages occur as veins, in disseminated form and as clots, and document retrograde fluid infiltration. These features are associated with late-state CO2-rich fluid inclusions. Stable isotope analyses of calcites indicates that the retrograde fluids interacted with meta-igneous and supracrustal lithologies, but the precise timing of the retrogression is as yet unknown