Hollow cathode chemical modelling

In this paper the state of hollow cathode life time modelling at the University of Southampton will be reported. Two models have been developed: one for BaO depletion from the hollow cathode insert and another for low work function compounds deposition and desorption. The model developed to predict BaO depletion from hollow cathode insert will be presented together with some comparison between experimental and numerical data to prove its validity.A model for low work function compounds deposition and desorption will also be presented. This model will be used to simulate the NSTAR cathode showing a very conservative estimate of the cathode life due to conservative character of the hypotheses made in the model development and due to the chosen criteria for the end of life

A dual Stage ion engine for high impulse missions

In this paper, the applicability of dual stage ion opticsand in particular of the so-called dual stage ion engine to highpower, high specific impulse missions will be evaluated. First, theperformance limits of conventional two gridded ion engines (GIE)will be discussed and the advantages provided by dual stage ionengines reported. The limits of applicability of a dual stage ionengine will be analyzed analytically and the results confirmednumerically. The lifetime and performance of a three griddeddual stage ion engine (DS3G) will be numerically investigated andcompared to those of a conventional GIE assessing for the firsttime in the open literature under what condition dual stage ionoptics provide performance improvements over conventional GIEsand what is its impact on the thruster lifetime. Dual stage ionengines have been found to be capable of providing higher thrustdensity and longer lifetime with respect to conventional griddedion engines

Skeletal muscle: a significant novel neurohypophyseal hormone-secreting organ

Vasopressin (arg8-vasopressin) and oxytocin are closely relalated hormones, synthesized as pre-hormones in the magnocellular neurons of the paraventricular Q6 and supraoptic nuclei of the hypothalamus. Vasopressin and oxytocin are secreted in response to a variety of physiological stimuli, serving such different functions as controlling water balance, milk ejection, uterine contraction, mood, and parental behavior (Lechan and Toni, 2000; Costa et al., 2014a)

Inflation Targeting, Price-Level Targeting, and Fluctuations in Canada's Terms of Trade

Coletti and Lalonde compare inflation targeting and price-level targeting in the context of a small open economy subject to sizable terms-of-trade shocks. The authors summarize recent research that compares the ability of price-level targeting and inflation targeting to stabilize the macroeconomy when confronted with shocks similar to those experienced by Canada in recent years. Their preliminary results suggest that price-level targeting may represent a feasible alternative to traditional inflation targeting. Their article also provides insight into the direction of current research in this area at the Bank.

Conference Summary: Price Adjustment and Monetary Policy

The 2002 Bank of Canada Conference focused on price adjustment, a critically important issue for monetary policy. Given the acceptance throughout the 1990s and 2000s of the existence of price stickiness in goods or labour markets, or both, and of the important role that monetary policy can play in an economy, the time was right for a conference that would focus on current developments in this area of research, particularly within a Canadian context. Conference papers covering both theoretical and empirical studies explored such themes as sources of the persistence of inflation, forward-looking models of inflation, models of inflation in open economies, the macroeconomic effects of technology shocks, and models of the interaction between wages, prices, and real economic outcomes.

Default Logic in a Coherent Setting

In this talk - based on the results of a forthcoming paper (Coletti, Scozzafava and Vantaggi 2002), presented also by one of us at the Conference on "Non Classical Logic, Approximate Reasoning and Soft-Computing" (Anacapri, Italy, 2001) - we discuss the problem of representing default rules by means of a suitable coherent conditional probability, defined on a family of conditional events. An event is singled-out (in our approach) by a proposition, that is a statement that can be either true or false; a conditional event is consequently defined by means of two propositions and is a 3-valued entity, the third value being (in this context) a conditional probability