Measurements of Residual Stresses in Cold-Rolled 304 Stainless Steel Plates Using X-Ray Diffraction with Rietveld Refinement Method

The determination of the residual stresses using X-ray powder diffraction in a series of cold-rolled 304 stainless steel plates, deforming 0, 34, 84, 152, 158, 175 and 196 % reduction in thickness has been carried out. The diffraction data were analyzed using the Rietveld structure refinement method. The analysis shows that for all specimens, the martensite particles are closely in compression and the austenite matrix is in tension. Both the martensite and austenite, for a sample reducing 34% in thickness (containing of about 1% martensite phase) the average lattice strains are anisotropic and decrease approximately exponential with an increase in the corresponding percent reduction (essentially phase content). It is shown that this feature can be qualitatively understood by taking into consideration the thermal expansion mismatch between the martensite and austenite grains. Also, for all cold-rolled stainless steel specimens, the diffraction peaks are broader than the unrolled one (instrumental resolution), indicating that the strains in these specimens are inhomogeneous. From an analysis of the refined peak shape parameters, the average root-mean square strain, which describes the distribution of the inhomogeneous strain field, was predicted. The average residual stresses in cold-rolled 304 stainless steel plates showed a combination effect of hydrostatic stresses of the martensite particles and the austenite matrix.Received: 14 March 2008; Revised: 13 October 2008; Accepted: 6 November 200

Project portfolio management: The linchpin in strategy processes

© Cambridge University Press 2017. Introduction Project portfolio management (PPM) is a central component of organizational project management (OPM), especially through its role in both the formulation and the delivery of organizational strategy. Corporate activities are increasingly carried out in the form of projects, in a trend that has been called “projectification” (Midler, 1995). In particular, for the implementation of complex innovations, it is not enough for organizations to focus on the successful management of individual innovation projects; they must also manage a large number of interdependent projects from a portfolio perspective. In today's dynamic environment, organizing by projects has become the rule rather than the exception, and organizations face challenges in managing these large project landscapes (programs and portfolios). The management of project portfolios is closely linked to the implementation of strategies. As strategies are ultimately implemented by projects, PPM – as a link between corporate strategy and projects – plays a central role (Meskendahl, 2010). In most research and practice this role is considered from a top-down perspective: strategies are considered to be a given yardstick for the prioritization and selection of projects and the allocation of resources. From such perspectives, PPM acts as the recipient of strategic goals and requirements that need only to be operationalized. However, the strategic management literature has long recognized the importance of emergent strategy; and that the realized strategy (the strategy that is actually implemented) often strays from the intended strategy (Mintzberg, 1978). Surprisingly, this is hardly considered in existing research models and standards for PPM (PMI, 2013). While there is some empirical evidence to suggest that hierarchical, formal, top-down approaches are not the actual practice of PPM (Christiansen & Varnes, 2009; Jerbrant & Gustavsson, 2013; Martinsuo, 2013), a much broader debate is needed to fully explore the role of PPM in the context of emergent strategies. The goal of this chapter is therefore to explore the role of PPM in the relationship between the formulation and implementation of strategy and consider both the top-down approach as well as the bottom-up strategy emergence. We first discuss emergence in the context of strategy implementation and the role of different phases in the PPM process that affect strategy implementation

Observations of Al, Fe and Ca(+) in Mercury's Exosphere

We report 5-(sigma) tangent column detections of Al and Fe, and strict 3-(sigma) tangent column upper limits for Ca(+) in Mercury's exosphere obtained using the HIRES spectrometer on the Keck I telescope. These are the first direct detections of Al and Fe in Mercury's exosphere. Our Ca(-) observation is consistent with that reported by The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft

Business Case Control in Project Portfolios - An Empirical Investigation of Performance Consequences and Moderating Effects

© 1988-2012 IEEE. Practitioners place strong emphasis on business cases with the expectation that using business cases to inform and drive investment decisions will assist in creating value from those investments. Maximizing the value generated by project investments is a central aim of the project portfolio management, and the business case provides the underlying rationale for the evaluation of the value created in each project. However, research regarding the use of business cases at a project portfolio level is scarce, and there is a little guidance for portfolio managers on when and how to control the business cases. We identify three elements of a business case control at the portfolio level - the initial review, the ongoing monitoring during the project execution, and the postproject tracking until the business case is realized - and investigate the relationship between business case control and project portfolio success. Furthermore, we analyze enablers and contingencies for the application of the business case control. Based on a cross-industry sample of 183 firms, we find that the business case control is positively related to the project portfolio success. Accountability for business case realization and corresponding incentive systems increase this positive effect. Finally, we show that the portfolio complexity also positively moderates the relationship

The Role of Innovation Portfolio Management in the Nexus between Deliberate and Emergent Innovation Strategies

Planning and implementing innovation strategies are typically considered to be top-down processes and innovation portfolio management plays a decisive role in this context by aligning the project portfolio to the firm’s strategy. However, in strategic management research it is well accepted that strategies are not solely deliberate but can also be emergent. Thus, between top-down innovation strategy formulation and its implementation, responding dialectic elements are required to sense emerging strategic impetuses and cope with changing environmental conditions. This paper addresses the role of portfolio management in the nexus between strategy formulation and implementation. Using a sample of 182 medium and large firms with two informants, we show that portfolio management not only fosters the implementation of intended innovation strategies through vertical integration but also discloses strategic opportunities by unveiling emerging patterns. The findings show that portfolio management contributes to innovation portfolio success by supporting both the implementation of deliberate and emergent strategies through vertical integration and strategic disclosure. The effects are complementary in that both activities increase the positive effects of the other. Furthermore we find that strategic control (i.e. premise control, implementation control, and strategic surveillance) on a portfolio level indirectly contributes to success mediated by vertical integration and strategic disclosure. Finally, we show that the influence of vertical integration on innovation portfolio success is reduced under high environmental turbulence

Turbulence Measurements in Dilute Polymer Flows

A hot-film sensor was flush-mounted in the wall of a four-inch pipe and was calibrated as a function of wall shear stress. Flows with water and with homogeneous aqueous solutions of Polyox WSR-301 were utilized. The heat transfer characteristics of the sensor were reduced for polymer flows. Measurements of the number of zeroes and the frequency spectra for the turbulent fluctuations were obtained for a variety of test conditions. The effects of Polyox WSR-301 on surface pressure fluctuations on both smooth and rough surfaces were also measured

A Concept for Small, Remotely Operated, Coronagraph located at Small Observatory to Obtain Frequent Low-cost Remote Observations of the Lunar Exosphere and the Mercurian Tail

The sodium in the lunar exosphere is a marker species for studying the lunar exosphere because the element possesses two strong resonance transitions from the ground state whose wavelengths fall in the visible spectrum near 590 nm. Emissions at these wavelengths are thus, observable from Earth. Observations have shown that the exosphere responds in a complex way to the external processes (impact vaporization, sputtering, and photon stimulated desorption) that weather the lunar regolith to produce the sodium. Unraveling the sodium production allows us to study the processes that weather the regolith. Obtaining the extensive time sequence of observations required to unravel the sources of sodium using conventional observatories is impractical, and too expensive. Effectively imaging the lunar sodium exosphere dose to the Moon requires an off-axis rejection of scattered light that can only be obtained with a coronagraph. A related problem. the observation of the sodium tail of Mercury, can be addressed as well only by coronagraphic observations. We present here a concept for a small, rugged coronagraph sited at an observatory dedicated to remote robotic observing (the Winer Observatory in Sonoita Arizona) that can obtain the quality and quantity of lunar sodium observations needed to answer these questions. The design uses Commercial Off the Shelf Technology (COTS). If this facility is operational by 2013. the observations will be concurrent with the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission

The Perceived Value of Certification by Certified Perioperative Nurses

We conducted this study to determine the perceived value of certification in perioperative nursing. Following development and pilot-testing, we mailed the 18-item Likert-type instrument, the Perceived Value of Certification Tool (PVCT), to a sample of 2750 perioperative nurses who had earned the CNOR or CRNFA credential or both. A total of 1398 surveys were returned (50.8% response rate). Factor analysis extracted three factors, accounting for 61% of the variance: personal value, recognition by others, and professional practice. Internal consistency reliability testing (Cronbach\u27s α) identified a standardized α of .924. Over 90% of respondents agreed or strongly agreed with statements about the value of certification related to feelings of personal accomplishment and satisfaction, validating specialized knowledge, indicating professional growth, attainment of a practice standard, personal challenge, and professional commitment, challenge, and credibility. These results are consistent with previously published literature on specialty certification in nursing

Observation of Neutral Sodium Above Mercury During the Transit of November 8, 2006

We mapped the absorption of sunlight by sodium vapor in the exosphere of Mercury during the transit of Mercury on November 8, 2006, using the IBIS Interferometric BIdimensional Spectrometer at the Dunn Solar Telescope operated by the National Solar Observatory at Sunspot, New Mexico. The measurements were reduced to line-of-sight equivalent widths for absorption at the sodium D2 line around the shadow of Mercury. The sodium absorption fell off exponentially with altitude up to about 600 km. However there were regions around north and south polar-regions where relatively uniform sodium absorptions extended above 1000 km. We corrected the 0-600 km altitude profiles for seeing blur using the measured point spread function. Analysis of the corrected altitude distributions yielded surface densities, zenith column densities, temperatures and scale heights for sodium all around the planet. Sodium absorption on the dawn side equatorial terminator was less than on the dusk side, different from previous observations of the relative absorption levels. We also determined Earthward velocities for sodium atoms, and line widths for the absorptions. Earthward velocities resulting from radiation pressure on sodium averaged 0.8 km/s, smaller than a prediction of 1.5 km/s. Most line widths were in the range of 20 mA after correction for instrumental broadening, corresponding to temperatures in the range of 1000 K