Enabling Mobile Neutron Detection Systems with CLYC

Cs2LiYCl6:Ce3+ (CLYC) has the desirable property of being sensitive to both gamma rays and neutrons while producing waveforms suitable for pulse shape discrimination (PSD) to determine which radiation was detected. This dissertation examines the behavior of CLYC to support its further development for mobile and portable applications. First, the feasibility of performing PSD with CLYC and an inexpensive data acquisition system was examined. This system was able to clearly distinguish both events with a figure of merit of 1.42. Next, the performance of a SiPM was compared to a traditional PMT. Analysis showed that the SiPM degraded the energy resolution by an average of 34.0±0.7% (at 662 keV). Measurements were also taken using a CLYC crystal with two optical windows which was rotated to determine the direction of a neutron source with an accuracy of ±10°. An analysis of the ability of clustering algorithms to discriminate between gamma ray and neutron interactions was also performed. A methodology was developed and applied to separate these two interactions and provide the ability to isolate the 35Cl(n,p)35S interaction with thermal neutrons, which occurs close to the gamma ray region and is difficult to separate visually. Finally, the effect of temperature on a 7Li (99%) enriched CLYC crystal (important when the 35Cl(n,p)35S interaction is more desirable than 6Li(n,t)α interaction) was examined. Measurements agreed with previous results from 6Li (95%) enriched CLYC, but also indicated that identifying the cluster corresponding to thermal neutrons interacting with 35Cl was temperature dependent

Copper Doping of Zinc Oxide by Nuclear Transmutation

This research verifies that neutron irradiation of zinc oxide leads to Cu-doping of the material by nuclear transmutation. After irradiation, both Zn-65 and Zn-69m were detected and positively identified. Zn-65 was visible at all times while Zn-69m was visible when the samples were measured within a few Zn-69m half-lifes. All decay paths of Zn-65 lead to Cu-65 and the detection of the 1115.5 keV characteristic gamma ray from this decay clearly indicated that Cu-65 was being created. Previous electron paramagnetic resonance (EPR) spectroscopic results were replicated to determine the spectrum of copper impurities in ZnO as well as the corresponding spacing between signals in the hyperfine spectrum for the two stable isotopes of copper. This spacing was found to be 1015 ± 1 G for Cu-65 and 947 ± 1 G for Cu-63. The separation of EPR signals in the Cu hyperfine spectrum measured after neutron irradiation of the samples was found to be 1013 ± 1 G confirming the creation of only Cu-65 during irradiation, as predicted by theory

The relation between BPM culture, BPM methods, and process performance: Evidence from quantitative field studies

Business process management (BPM) research conceptualizes BPM culture as a type of organizational culture that supports BPM. No quantitative fieldwork has so far examined how such a supporting role manifests itself. We study the relationship between BPM culture, BPM methods, and process performance empirically. Our analysis of multiple survey data sets from a total of 581 practitioners of multiple industries suggests that BPM methods indirectly contribute to process performance by establishing a BPM culture. This finding updates the prevalent assumption that the correct application of methods yields direct performance benefits. We discuss several implications for theory and practice

The Convergence of Business Process Management and Digital Innovation

Business process management is a prolific field of research and an area of strong industrial uptake with roots in both management science and information systems engineering. Traditionally, business process management has largely been utilized in an inward-looking way with the aim to improve operations, eliminate waste, and increase efficiency. Recent developments around digital innovation challenge conventional ideas of process reengineering with a strong emphasis on the external market and exploration. In this talk, we will discuss the complementarity of BPM and digital innovation

The effects of symmetry on the dynamics of antigenic variation

In the studies of dynamics of pathogens and their interactions with a host immune system, an important role is played by the structure of antigenic variants associated with a pathogen. Using the example of a model of antigenic variation in malaria, we show how many of the observed dynamical regimes can be explained in terms of the symmetry of interactions between different antigenic variants. The results of this analysis are quite generic, and have wider implications for understanding the dynamics of immune escape of other parasites, as well as for the dynamics of multi-strain diseases.Comment: 21 pages, 4 figures; J. Math. Biol. (2012), Online Firs

How store managers can empower their teams to engage in constructive deviance: Theory development through a multiple case study

In this paper, we explore how leaders enable constructive deviance in teams they manage. We report on a qualitative field study of two hierarchical layers of store management in 17 supermarket store teams. We focus on the emergence of constructive deviance – better ways of creating value by departing from common ways of working – and how store leaders can enable this behavior. Our inductive analysis from the multiple case data suggests that store management can enable constructive deviance by combining empowering leadership behaviors with adequate levels of contingent reward and monitoring behaviors. These findings allow us to develop new hypotheses about the linkages between constructive deviance, psychological empowerment, and leadership. We detail implications for store management and we describe several future research opportunities on the concept of constructive deviance, its enablement through empowering leadership, and the relationship between organizational norms and constructive deviance

Unternehmerisches Umdenken

Die Covid-19-Pandemie bringt viele Veränderungen. Es lohnt sich, bereits jetzt umzudenken für die Zeit danach.Footnot

Copper Doping of ZnO Crystals by Transmutation of \u3csup\u3e64\u3c/sup\u3eZn to \u3csup\u3e65\u3c/sup\u3eCu: An Electron Paramagnetic Resonance and Gamma Spectroscopy Study

Transmutation of 64Zn to 65Cu has been observed in a ZnO crystal irradiated with neutrons. The crystal was characterized with electron paramagnetic resonance (EPR) before and after the irradiation and with gamma spectroscopy after the irradiation. Major features in the gamma spectrum of the neutron-irradiated crystal included the primary 1115.5 keV gamma ray from the 65Zn decay and the positron annihilation peak at 511 keV. Their presence confirmed the successful transmutation of 64Zn nuclei to 65Cu. Additional direct evidence for transmutation was obtained from the EPR of Cu2+ ions (where 63Cu and 65Cu hyperfine lines are easily resolved). A spectrum from isolated Cu2+ (3d9) ions acquired after the neutron irradiation showed only hyperfine lines from 65Cu nuclei. The absence of 63Cu lines in this Cu2+ spectrum left no doubt that the observed 65Cu signals were due to transmuted 65Cu nuclei created as a result of the neutron irradiation. Small concentrations of copper, in the form of Cu+-H complexes, were inadvertently present in our as-grown ZnO crystal. These Cu+-H complexes are not affected by the neutron irradiation, but they dissociate when a crystal is heated to 900 °C. This behavior allowed EPR to distinguish between the copper initially in the crystal and the copper subsequently produced by the neutron irradiation. In addition to transmutation, a second major effect of the neutron irradiation was the formation of zinc and oxygen vacancies by displacement. These vacancies were observed with EPR

Data-Driven, Data-Informed, Data-Augmented: How Ubisoft’s Ghost Recon Wildlands Live Unit Uses Data for Continuous Product Innovation

To stay ahead of the competition, firms must continuously learn from their customers and swiftly adopt those lessons to improve their products. A unit at Ubisoft, a leading game publisher headquartered in Paris, has established a three-pronged approach to drive product innovation based on three practices: data-driven exploration, data-augmented ideation, and data-informed validation. By establishing processes and capabilities for these practices and blending them in a portfolio approach to product design, they maximize the value generation potential of the data at their disposal. Product development in a variety of industries can benefit from the lessons of these data-oriented innovation practices