Elastic Properties in Tension and Shear of High Strength Nonferrous Metals and Stainless Steel - Effect of Previous Deformation and Heat Treatment

A resume is given of an investigation of the influence of plastic deformation and of annealing temperature on the tensile and shear elastic properties of high strength nonferrous metals and stainless steels in the form of rods and tubes. The data were obtained from earlier technical reports and notes, and from unpublished work in this investigation. There are also included data obtained from published and unpublished work performed on an independent investigation. The rod materials, namely, nickel, monel, inconel, copper, 13:2 Cr-Ni steel, and 18:8 Cr-Ni steel, were tested in tension; 18:8 Cr-Ni steel tubes were tested in shear, and nickel, monel, aluminum-monel, and Inconel tubes were tested in both tension and shear. There are first described experiments on the relationship between hysteresis and creep, as obtained with repeated cyclic stressing of annealed stainless steel specimens over a constant load range. These tests, which preceded the measurements of elastic properties, assisted in devising the loading time schedule used in such measurements. From corrected stress-set curves are derived the five proof stresses used as indices of elastic or yield strength. From corrected stress-strain curves are derived the secant modulus and its variation with stress. The relationship between the forms of the stress-set and stress-strain curves and the values of the properties derived is discussed. Curves of variation of proof stress and modulus with prior extension, as obtained with single rod specimens, consist in wavelike basic curves with superposed oscillations due to differences of rest interval and extension spacing; the effects of these differences are studied. Oscillations of proof stress and modulus are generally opposite in manner. The use of a series of tubular specimens corresponding to different amounts of prior extension of cold reduction gave curves almost devoid of oscillation since the effects of variation of rest interval and extension spacing were removed. Comparison is also obtained between the variation of the several properties, as measured in tension and in shear. The rise of proof stress with extension is studied, and the work-hardening rates of the various metals evaluated. The ratio between the tensile and shear proof stresses for the various annealed and cold-worked tubular metals is likewise calculated. The influence of annealing or tempering temperature on the proof stresses and moduli for the cold-worked metals and for air-hardened 13:2 Cr-Ni steel is investigated. An improvement of elastic strength generally is obtained, without important loss of yield strength, by annealing at suitable temperature. The variation of the proof stress and modulus of elasticity with plastic deformation or annealing temperature is explained in terms of the relative dominance of three important factors: namely, (a) internal stress, (b) lattice-expansion or work-hardening, and (c) crystal reorientation. Effective values of Poisson's ratio were computed from tensile and shear moduli obtained on tubular specimens. The variation of Poisson's ratio with plastic deformation and annealing temperature is explained in terms of the degree of anisotropy produced by changes of (a) internal stress and (b) crystal orientation

Practical study of the errors affecting surveying operations

The errors affecting linear measurements are so numerous, of such a variable nature and so inter -connected, that the ultimate accuracy of measuring distances is more difficult to assess than that of any other surveying operation. The greatest source of trouble is the pronounced interference of cumulative errors due principally to using an incorrect chain or tape, disregarding slòpe, poor alignment, the unevenness of the ground and the effect of sag.The care with which the measurements are made is also an important factor, and in many cases, in mine surveying particularly, the operation of measuring is left in the hands of unskilled workmen, and appreciable marking and reading errors are introduced

Frequency-dependent and correlational selection pressures have conflicting consequences for assortative mating in a color-polymorphic lizard, Uta stansburiana

Acknowledgments We would like to thank the numerous undergraduate researchers involved with this project for their invaluable assistance in lizard rearing and data collection. We also thank D. Haisten, A. Runemark, Y. Takahashi, and M. Verzijden for insightful comments on the manuscript. This project was funded by National Science Foundation DEBOS-15973 to A.G.M. and B.R.S.Peer reviewedPublisher PD

The Effect of Business Improvement Methods on Innovation in Small and Medium-Sized Enterprises in Peripheral Regions

The effect of business improvement methods on innovation in small and medium-sized enterprises in peripheral regions, Regional Studies. This paper tests whether commonly used business improvement methods (BIM) foster or inhibit innovation in small and medium-sized enterprises (SMEs) in peripheral regions. The findings show that adopting BIM diverts firms away from successful innovation (i.e., in terms of new products/services and new processes in the past three years), and instead is associated with undertaking innovation-related activities while remaining non-innovators. Indeed, reinforcing BIM (through greater ‘depth’ of use) may lead to further exclusion from successful innovation

Alley coppice: combining willow SRC with poplar and cherry trees

PosterShort Rotation willow Coppice (SRC) is an important source of biomass energy in Ireland. Growing and intensively managing trees at wide spacing generates high value timber, sequesters carbon and delivers other ecosystem services. The alley coppice system combines the production of SRC with high value timber trees. Three alley coppice experiments were established to study the interaction of SRC with high value timber trees. In Experiment 1 the cherry variety - willow interaction is investigated: 5 willow varieties (and a mixture of all 5); (‘Resolution’, ‘Beagle’, ‘Endeavour’, ‘Olaf’ and ‘Terra Nova’) interact with rows of clonal wild cherry: ‘Neso’, ‘Pluto’, ‘Saturn’, ‘Hermes’ and ‘Concordia’ and one control of seedlings. The willow is planted in double rows 0.75m by 1.5m apart. Cherry trees are planted at an intra-row tree to tree spacing of 2.5m and inter-row spacing of 12.75m and alley widths of 1m & 2 m. In Experiment 2, 18 year old poplars (‘Hoogwoorst’, ‘Beaupre’, ‘Gebec’ ‘Trichobel’) are 5m apart in 14m wide alleys, planted with each of the 7 willow varieties (6 monoculture – as above in Experiment 1 but including ‘Tora’ & one mixed willow treatment simulating commercial planting). In Experiment 3, cherry are inter-planted along an existing commercial SRC as single tree plots in a linear randomised design. Cherry trees are 2.5m apart in rows; each is 2.5 m from nearest willow stool. Each block contains 5 sub plots. Each sub plot contains 26 tree genotypes: 22 German varieties, 2 French varieties and seedlings as controls. For each experiment the growth and yield of the tree and SRC components and their interactions will be measured and evaluated

Research to improve the design of driven pile foundations in chalk: the ALPACA project

Large numbers of offshore wind turbines, near-shore bridges and port facilities are supported by driven piles. The design and installation of such piles is often problematic in Chalk, a low-density, porous, weak carbonate rock, which is present under large areas of NW Europe. There is little guidance available to designers on driveability, axial capacity, the lateral pile resistance which dominates offshore wind turbine monopile behaviour, or on how piles can sustain axial or lateral cyclic loading. This paper describes the ALPACA project which involves comprehensive field testing at a low-to-medium density chalk research test site. The project is developing new design guidance through comprehensive field testing and analysis combined with in-situ testing campaigns and advanced static-and-cyclic laboratory testing on high quality block and rotary core samples

High-temperature Hydrogen Chloride Releases from Mixtures of Sodium Chloride with Sulfates: Implications for the Chlorine-Mineralogy as Determined by the Sample Analysis at Mars Instrument on the Curiosity Rover in Gale Crater, Mars

Hydrogen chloride releases above 500 C occurred in several samples analyzed by the Sample Analysis at Mars (SAM) evolved gas analyzer on the Curiosity rover in Gale crater. These have been attributed to reactions between chlorides (original or from oxychlorine decomposition) and water. Some of these HCl releases that peaked below the melting temperature of common chlorides did not co-evolve with oxygen or water, and were not explained by laboratory analog work (Figure 1). Therefore, these HCl releases were not caused by MgCl2 or soley due to reactions between water and melting chlorides. The goal of this work was to explain the HCl releases that did not co-evolve with oxygen or water and occurred below the melting point of common chlorides, which have not been explained by previous laboratory analog work. This work specifically evaluates the role of evolved SO2 in the production of HCl