Photon induced secondary electron emission

Numerical models for predicting photon-induced secondary electron emission are presented. The results are compared with experimental measurements made using a Co-60 gamma ray source

Geoids in General Relativity: Geoid Quasilocal Frames

We develop, in the context of general relativity, the notion of a geoid -- a surface of constant "gravitational potential". In particular, we show how this idea naturally emerges as a specific choice of a previously proposed, more general and operationally useful construction called a quasilocal frame -- that is, a choice of a two-parameter family of timelike worldlines comprising the worldtube boundary of the history of a finite spatial volume. We study the geometric properties of these geoid quasilocal frames, and construct solutions for them in some simple spacetimes. We then compare these results -- focusing on the computationally tractable scenario of a non-rotating body with a quadrupole perturbation -- against their counterparts in Newtonian gravity (the setting for current applications of the geoid), and we compute general-relativistic corrections to some measurable geometric quantities.Comment: 24 pages, 8 figures; v2: reference added; v3: introduction clarified, reference adde

Synthesis and characteristics of polyarylene ether sulfones

A method utilizing potassium carbonate/dimethyl acetamide, as base and solvent respectively, was used for the synthesis of several homopolymers and copolymers derived from various bisphenols. It is demonstrated that this method deviates from simple second order kinetics; this deviation being due to the heterogeneous nature of the reaction. Also, it is shown that a liquid induced crystallization process can improve the solvent resistance of these polymers. Finally, a Monte Carlo simulation of the triad distribution of monomers in nonequilibrium copolycondensation is discussed

Role of the multidisciplinary team in the care of the tracheostomy patient

Barbara Bonvento,1 Sarah Wallace,1,2 James Lynch,1 Barry Coe,1 Brendan A McGrath1 1Acute Intensive Care Unit, University Hospital South Manchester, Manchester, 2Royal College of Speech and Language Therapists, London, UK Abstract: Tracheostomies are used to provide artificial airways for increasingly complex patients for a variety of indications. Patients and their families are dependent on knowledgeable multidisciplinary staff, including medical, nursing, respiratory physiotherapy and speech and language therapy staff, dieticians and psychologists, from a wide range of specialty backgrounds. There is increasing evidence that coordinated tracheostomy multidisciplinary teams can influence the safety and quality of care for patients and their families. This article reviews the roles of these team members and highlights the potential for improvements in care. Keywords: tracheotomy, physiotherapist, Speech & Language, Nursin

Polyaryl ethers and related polysiloxane copolymer molecular coatings preparation and radiation degrdation

Poly(arylene ether sulfones) comprise a class of materials known as engineering thermoplastics which have a variety of important applications. These polymers are tough, rigid materials with good mechanical properties over a wide temperature range, and they are processed by conventional methods into products typically having excellent hydrolytic, thermal, oxidative and dimensional stability. Wholly aromatic random copolymers of hydroquinone and biphenol with 4.4 prime dichlorodiphenyl sulfone were synthesized via mechanical nucleophilic displacement. Their structures were characterized and mechanical behavior studied. These tough, ductile copolymers show excellent radiation resistance to electron beam treatment and retain much of the mechanical properties up to at least 700 Mrads under argon