Probing carrier behaviour at the nanoscale in gallium nitride using low voltage cathodoluminescence

The increasing application of GaN in blue and UV light emitting diodes and lasers has generated considerable interest in its optical and electrical properties. These optical devices exhibit extremely high emission efficiencies despite the presence of a very high concentration of threading dislocations (108 1010 cm-2) that act as non-radiative recombination channels. This perceived contradiction can be been explained by small (< 100 nm) carrier diffusion lengths which effectively negate the effect of the threading dislocations on the radiative recombination efficiency. These short exciton and minority carrier diffusion lengths in GaN can be explored by cathodoluminescence (CL) microscopy and spectroscopy using a SEM equipped with a Schottky field emission gun operating at 1 kV

Modeling Organizational Project Management

© 2019 Project Management Institute, Inc. The contemporary discourse on organizational project management (OPM) complements project, program, and portfolio management with emerging elements, such as governance, projectification, the project management office (PMO), and organizational design. This creates the need for an integrated model that defines the content and roles in OPM. This article addresses this by conceptually developing a seven-layered model that organizes 22 OPM elements, ranging from the corporate level to the management of individual projects. A theory is developed to explain the interaction of the elements and the layers within the model

Response to "Comment on 'Carrier recombination near threading dislocations in GaN epilayers by low voltage cathodoluminescence'" [Appl. Phys. Lett. 97, 166101 (2010)]

Abstract : The authors are aware that there are number of theoretical models available to simulate cathodoluminescence (CL) contrast as a function of the distance, r, from a nonradiative defect. In our letter1 a simple expression, C(r)=C0 exp(−r/L)C(r)=C0 exp(−r/L), was chosen to compare the diffusion length, L, from GaN samples with different n-doping levels over a range of low electron beam energies. This approach is widely used in other studies of CL dislocation contrast as pointed out in the comment on the letter and it was found to provide an acceptable fit to the experimental CL contrast data

The Digital Flynn Effect: Complexity of Posts on Social Media Increases over Time

Parents and teachers often express concern about the extensive use of social media by youngsters. Some of them see emoticons, undecipherable initialisms and loose grammar typical for social media as evidence of language degradation. In this paper, we use a simple measure of text complexity to investigate how the complexity of public posts on a popular social networking site changes over time. We analyze a unique dataset that contains texts posted by 942, 336 users from a large European city across nine years. We show that the chosen complexity measure is correlated with the academic performance of users: users from high-performing schools produce more complex texts than users from low-performing schools. We also find that complexity of posts increases with age. Finally, we demonstrate that overall language complexity of posts on the social networking site is constantly increasing. We call this phenomenon the digital Flynn effect. Our results may suggest that the worries about language degradation are not warranted

Exploring vertical and horizontal leadership in projects: A comparison of Indian and Australian contexts

Project-based organisational forms are becoming more and more prevalent in many industries, and leadership influences projects' success ultimately impacting the organisational performance. Two types of leadership styles have been explored: vertical and horizontal. This study aims to identify the nature and balance of vertical and horizontal leadership in projects to allow project managers to consciously poly these approaches in different situations. A case study-based approach is adopted wherein, two case studies from India and three case studies from Australia are included . A comparative study of leadership styles is performed to find the best contextual fit for leadership styles. The findings reveal that that national cultural is not a major factor in influencing project leadership. Rather, organisational culture and a shared understanding on leadership practices is what influences whether vertical or horizontal leadership will be more prevalent. Senior leaders' initiatives to create and support a culture of sharing ideasand decisions, backed by project manager's approach enable effective balance between horizontal and vertical leadership. Horizontal leadership is further by regular meetings and social interactions. Prevalence of horizontal leaderships is demonstrated in technical decisions, as team members have the best expertise to address technical issues. In contrast, strategic decisions are normally discussed with the project manager and often escalated to senior leaders for decisions

Gender specific factors contributing to cognitive resilience in APOE ɛ4 positive older adults in a population-based sample

Although APOE ɛ4 has been identified as the strongest genetic risk factor for Alzheimer’s Disease, there are some APOE ɛ4 carriers who do not go on to develop Alzheimer’s disease or cognitive impairment. This study aims to investigate factors contributing to this “resilience” separately by gender. Data were drawn from APOE ɛ4 positive participants who were aged 60 + at baseline in the Personality and Total Health Through Life (PATH) Study (N = 341, Women = 46.3%). Participants were categorised into “resilient” and “non-resilient” groups using Latent Class Analysis based on their cognitive impairment status and cognitive trajectory across 12 years. Logistic regression was used to identify the risk and protective factors that contributed to resilience stratified by gender. For APOE ɛ4 carriers who have not had a stroke, predictors of resilience were increased frequency of mild physical activity and being employed at baseline for men, and increased number of mental activities engaged in at baseline for women. The results provide insights into a novel way of classifying resilience among APOE ɛ4 carriers and risk and protective factors contributing to resilience separately for men and women

Balancing person-centric and team-centric leadership in projects

Final Report of the PMiI Sponsored Research Gran

Laboratory Characterization and Astrophysical Detection of Vibrationally Excited States of Vinyl Cyanide in Orion-KL

New laboratory data of CH$_2$CHCN (vinyl cyanide) in its ground and vibrationally excited states at the microwave to THz domain allow searching for these excited state transitions in the Orion-KL line survey. Frequency-modulated spectrometers combined into a single broadband 50-1900 GHz spectrum provided measurements of CH$_2$CHCN covering a spectral range of 18-1893 GHz, whose assignments was confirmed by Stark modulation spectra in the 18-40 GHz region and by ab-initio anharmonic force field calculations. For analyzing the emission lines of CH$_2$CHCN species detected in Orion-KL we used the excitation and radiative transfer code (MADEX) at LTE conditions. The rotational transitions of the ground state of this molecule emerge from four cloud components of hot core nature which trace the physical and chemical conditions of high mass star forming regions in the Orion-KL Nebula. The total column density of CH$_2$CHCN in the ground state is (3.0$\pm$0.9)x10$^{15}$ cm$^{-2}$. We report on the first interstellar detection of transitions in the v10=1/(v11=1,v15=1) dyad in space, and in the v11=2 and v11=3 states in Orion-KL. The lowest energy vibrationally excited states of vinyl cyanide such as v11=1 (at 328.5 K), v15=1 (at 478.6 K), v11=2 (at 657.8 K), the v10=1/(v11=1,v15=1) dyad (at 806.4/809.9 K), and v11=3 (at 987.9 K) are populated under warm and dense conditions, so they probe the hottest parts of the Orion-KL source. Column density and rotational and vibrational temperatures for CH$_2$CHCN in their ground and excited states, as well as for the isotopologues, have been constrained by means of a sample of more than 1000 lines in this survey. Moreover, we present the detection of methyl isocyanide (CH$_3$NC) for the first time in Orion-KL and a tentative detection of vinyl isocyanide (CH$_2$CHNC) and give column density ratios between the cyanide and isocyanide isomers.Comment: 46 pages, 22 figures, 14 tables, 9 online table

A Manifesto for project management research

Project management research has evolved over the past five decades and is now a mature disciplinary field investigating phenomena of interest to academics, practitioners and policymakers. Studies of projects and project management practices are theoretically rich and scientifically rigorous. They are practically relevant and impactful when addressing the pursuit of operational, tactical and strategic advancements in the world of organisations. We want to broaden the conversation between project management scholars and other scholars from cognate disciplines, particularly business and management, in a true scholarship of integration and cross-fertilisation. This Manifesto invites the latter scholars to join efforts providing a foundation for further creative, theoretical and empirical contributions, including but not limited to tackling grand challenges such as climate change, pandemics, and global poverty. To this end, we identify five theses: Projects are often ‘agents of change’ and hence fundamental to driving the innovation and change required to tackle grand challenges. Much project management research leverages and challenges theories across disciplines, including business, organisation and management studies, contributing to developing new theories, including those specific to projects and temporary organisations. ‘Projects’ are useful units of analysis, project management research is ideal for scientific cross-fertilisation and project management scholars welcome academics from other communities to engage in fruitful conversations. As in many other fields of knowledge, the project management research community embraces diversity, welcoming researchers of different genders and various scientific and social backgrounds. Historically rooted in ‘problem-solving’ and normative studies, project management research has become open to interpretative and emancipatory research, providing opportunities for other business, management and organisational scholars to advance their knowledge communities