An idea used in the characterization of even perfect numbers is used, first, to derive new necessary conditions for the existence of an odd perfect number and, second, to show that there are no even 3-perfect numbers of the form 2aM , where M is odd and squarefree and a ≤ 718, besides the six known examples. –In memory of John Selfridge

Corresponding author: Tae-Yun Sung, M.D., Department of Anesthesiology and Pain Medicine, Konyang University Hospital, Konyang University College of Medicine, 158, Gwangeodong-ro, Seo-gu, Daejeon 302-718, Korea. Tel: 82-42-600-9316, Fax: 82-42-545-2132, E-mail: [email protected] This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License...

The effect of microstructural variations on the fracture toughness of Alloy 718 was reviewed. The metallurgical parameters surveyed in this paper included heat treatment, heat-to-heat variations, product-form variations, neutron irradiation and long-term thermal aging. Key microstructural features and operative fracture mechanisms were related to macroscopic fracture toughness properties.

cancelled 718 Posters, Monday 10 September © 2012 EFNS European Journal of Neurology 19 (Suppl. 1), 458–807 P2740 Influence of subclinical hypothyroidism on neuropsychological impairment in patients with multiple sclerosis E. Kiseleva1, N.N. Spirin2 1Neurology, 2Neurology with Medical Genetics and Neurosurgery, Yaroslavl State Medical Academy, Yaroslavl,

6,876,998 B2 * 4/2005 Evans ................................. .. 1/1 7,761,480 B2 * 7/2010 Toledano et a1. .. 707/804 7,818,313 B1* 10/2010 TsimelZon et a1. 707/718 8,131,540 B2 * 3/2012 Marchisio et a1. 704/9 2004/0034632 A1* 2/2004 Carmel et a1. 707/5 2005/0033711 A1* 2/2005 Horvitz et a1. . 706/5

Electrical Discharge Machine (EDM) parameters have a significant influence on machining characteristic like material removal rate (MMR) and tool wear rate (TWR). Inconel 718, which is widely used in the Medical, Marine, Architectural and food processing industries, is used as a work material. The tool electrode materials used are brass. Experiments are conducted using face centered central comp...

In this paper, the effect of TiC particle size on microstructure and mechanical properties an Inconel 718/TiC composite material fabricated using binder jetting additive manufacturing was investigated. Vacuum sintering, hot isostatic pressing heat treatment as post-processing were applied to samples. The addition 1 wt% micron-sized 718 matrix resulted in a significant increase strength relative...

Inconel 718, a high-temperature alloy, is a promising material for high-performance aerospace gas turbine engines components. However, the machining of the alloy is difficult owing to immense shear strength, rapid work hardening rate during turning, and less thermal conductivity. Hence, like ceramics and composites, the machining of this alloy is considered as difficult-to-turn materials. Laser...