Revealing the black-body regime of small-x deep-inelastic scattering through final-state signals

We derive the major characteristics of inclusive and diffractive final states in deep-inelastic scattering off heavy nuclei for the-high energy (small-x) kinematics in which the limit of complete absorption is reached for the dominant hadronic fluctuations in the virtual photon (the black-body limit of the process). Both the longitudinal and transverse distributions of the leading hadrons are found to be strikingly different from the corresponding ones within the leading-twist approximation, and hence provide unambiguous signals for the onset of the black-body limit.Comment: 12 pages, 1 figure, final version published in PR

Unitarity and the QCD-improved dipole picture

As a consequence of QCD factorization theorems, a wide variety of inclusive and exclusive cross sections may be formulated in terms of a universal colour dipole cross section at small $x$. It is well known that for small transverse size dipoles this cross section is related to the leading-log gluon density. Using the measured pion-proton cross section as a guide, we suggest a reasonable extrapolation of the dipole cross section to the large transverse size region. We point out that the observed magnitude and small $x$ rise of the gluon density from conventional fits implies that the DGLAP approximation has a restricted region of applicability. We found that `higher twist' or unitarity corrections are required in, or close to, the HERA kinematic region, even for small `perturbative' dipoles for scattering at central impact parameters. This means that the usual perturbative leading twist description, for moderate virtualities, $1 < Q^2 < 10$ GeV$^2$, has rather large `higher twist' corrections at small $x$. In addition, for these virtualities, we also find sizeable contributions from large non-perturbative dipoles (b \gsim 0.4 fm) to $F_2$, and also to $F_L$. This also leads to deviations from the standard leading twist DGLAP results, at small $x$ and moderate $Q^2$. Our model also describes the low $Q^2$ data very well without any further tuning. We generalize the Gribov unitarity limit for the structure functions of a hadron target to account for the blackening of the interaction at central impact parameters and to include scattering at peripheral impact parameters which dominate at extremely large energies.Comment: Final version, 38 pages, 16 figures, 1 table. A successful comparison to all low Q^2 HERA data is included. The discussion has been completely rewritten and extended to include both a detailed comparison with other models for the dipole cross section and also a new section on the approach to the black limit in DIS, including various new predictions. 23 new references have been added and several figures change

"We're still hitting things": The effectiveness of third-party processes for PIPELINE strike prevention

HIGH-PRESSURE GAS PIPELINES are vulnerable to damage in the course of building or maintaining other infrastructure, such as roads, water pipelines, and electricity or telecommunications cabling. Unlike other countries, there has never been a death or serious injury from a high-pressure gas pipeline strike in Australia and yet external interference continues to be the most common cause of pipeline damage despite a range of technical and legislative measures in place.This research project aims to enhance the safety strategies regarding third-party pipeline strikes by giving the pipeline sector a greater understanding of the motivations and priorities of those who work around pipeline assets and so how to work with them to achieve better outcomes. Using data gathered from more than 70 in-depth interviews, we explore empirically alternate understandings of risk amongst a range of stakeholders and individuals that are responsible in some way for work near or around high-pressure gas transmission pipelines in Australia. Outside the pipeline sector, much of the work around pipelines is conducted by those at the bottom of long chains of contractors and sub-contractors. We discuss perceptions of risk held by a range of third-party actors whose activities have the potential to threaten gas-pipeline integrity. We compare these views with gas-pipeline industry perceptions of risk, couched in terms of asset management, public safety, legal and insurance obligations, and reputation management This paper focuses on how financial risk - and so also management of the potential for pipeline strikes - is shifted down the third-party contractor chain. Added to this, incentives for timely project completion can unintentionally lead to situations where the potential for third-party contractors to strike pipelines increases. The data show that third-party contractors feel the time and cost impact of design or project changes most immediately. Consequently, strikes or near misses may result as sub-contractors seek to avoid perceived 'unnecessary' time delays along with the associated financial impact. We argue that efforts to reduce the potential for pipeline strikes need to be targeted at structural changes, rather than simply aimed at worker risk perception and enforcement of safety-compliance strategies

'We're still hitting things': The effectiveness of third party processes for pipeline strike prevention

High-pressure gas pipelines are vulnerable to damage in the course of building or maintaining other infrastructure, such as roads, water pipelines, electricity or telecommunications cabling. Unlike other countries, there has never been a death or serious injury from a high-pressure gas pipeline strike in Australia and yet external interference continues to be the most common cause of pipeline damage despite a range of technical and legislative measures in place. This research project aims to enhance the safety strategies regarding third party pipeline strikes by giving the pipeline sector a greater understanding of the motivations and priorities of those who work around pipeline assets and so how to work with them to achieve better outcomes. Using data gathered from more than 70 in-depth interviews, we explore empirically alternate understandings of risk amongst a range of stakeholders and individuals that are responsible in some way for work near or around high-pressure gas transmission pipelines in Australia. Outside the pipeline sector, much of the work around pipelines is conducted by those at the bottom of long chains of contractors and sub-contractors. We discuss perceptions of risk held by a range of third party actors whose activities have the potential to threaten gas pipeline integrity. We compare these views with gas pipeline industry perceptions of risk, couched in terms of asset management, public safety, legal and insurance obligations, and reputation management. This paper focuses on how financial risk and so also management of the potential for pipeline strikes is shifted down the third party contractor chain. Added to this, incentives for timely project completion can unintentionally lead to situations where the potential for third party contractors to strike pipelines increases. The data shows that third party contractors feel the time and cost impact of design or project changes most immediately. Consequently, strikes or near misses may result as sub-contractors seek to avoid perceived 'unnecessary' time delays along with the associated financial impact. We argue that efforts to reduce the potential for pipeline strike need to be targeted at structural changes, rather than simply aimed at worker risk perception and enforcement of safety compliance strategies

Passionate projects: practitioner reflections on emotion management

Purpose: The fundamental challenge for project management is dealing with people and their feelings. While there has been sporadic attention to the importance of emotions in project work, project management practices tend to neglect the role of emotions and emotional reflexivity. The authors use a symbolic interaction framework to present an in-depth exploration of emotions and emotional reflexivity in projects. Design/methodology/approach: Empirical data was gathered in 19 semi-structured interviews with diverse project managers to assess their experience of emotion (15 male, 4 female, early 20s to late 50s, 3–38 years of expertise). Transcribed interviews were thematically analysed using a sociology of emotions informed, grounded theory, interactional framework. Findings: The data revealed that emotional states are framed by factors specific to project management, including organisational change, project constraints and dealing with stakeholders. Explicitly managing emotions improved team engagement and project performance by acting as a catalyst for engaging in reflective practice and intuitive decision making. Practical implications: Given the widely held misconceptions of emotion as maladaptive, project management education must focus on empathy in communication and leadership if practitioners are to master valuable soft skills. Techniques for emotional reflection and learning feeling lessons must be incorporated into practice. Originality/value: The authors contribute to the emerging understanding that emotions matter in project management. The authors demonstrate the centrality of emotions in projects and the substantial impact they have on the wellbeing of practitioners and staff. Emotional reflexivity in practice, which is widely acknowledged yet tends to be ignored, is an essential part of the project manager's toolkit

Patient-Specific Fetal Dose Determination for Multi-Target Gamma Knife Radiosurgery: Computational Model and Case Report.

A 42-year-old woman at 29 weeks gestation via in vitro fertilization who presented with eight metastatic brain lesions received Gamma Knife stereotactic radiosurgery (GKSRS) at our institution.&nbsp;In this study, we report our clinical experience and a general procedure of determining the fetal dose from patient-specific treatment plans and we describe quality assurance measurements to guide the&nbsp;safe practice of multi-target GKSRS of pregnant patients.&nbsp;To estimate fetal dose pre-treatment, peripheral dose-to-focal dose ratios (PFRs) were measured in a phantom at the distance approximating the fundus of uterus. Post-treatment, fetal dose was calculated from the actual patient treatment plan.&nbsp;Quality assurance measurements were carried out via the extrapolation dosimetry method in a head phantom at increasing distances along the longitudinal axis.&nbsp;The measurements were then empirically fitted and the fetal dose was extracted from the curve.&nbsp;The computed and measured fetal dose values were compared with each other and associated radiation risk was estimated. Based on low estimated fetal dose from preliminary phantom measurements, the patient was accepted for GKSRS.&nbsp;Eight brain metastases were treated with prescription doses of 15-19 Gy over 143 min involving all collimator sizes as well as composite sector mixed shots.&nbsp;Direct fetal dose computation based on the actual patient's treatment plan estimated a maximum fetal dose of 0.253 cGy, which was in agreement with surface dose measurements at the level of the patient's uterine fundus during the actual treatment. Later phantom measurements also estimated fetal dose to be in the range of 0.21-0.28 cGy (dose extrapolation curve R2 = 0.998). Using the National Council on Radiation Protection and Measurements (NCRP) population-based model, we estimate the fetal risk of secondary malignancy, which is the primary toxicity after 25 weeks gestation, to be less than 0.01%.&nbsp;Of note, the patient delivered the baby via scheduled cesarean section at 36 weeks without complications attributable to the GKSRS procedure. GKSRS of multiple brain metastases was demonstrated to be safe and feasible during pregnancy.&nbsp;The applicability of a general patient-specific fetal dose determination method was also demonstrated for the first time for such a treatment

A New Methodology for Developing A Self-Report Psychodiversity Questionnaire: Update and Future Directions For A Work in Progress

A novel self-report methodology for the construction of a multidimensional questionnaire measure of psychodiversity is described and preliminary findings from three exploratory studies examining construct validity in relation to indices of well-being are discussed. Arising from these empirical endeavours, the notion of metamotivational state specific psychodiversity is proposed. The need for additional item generation for the combined alloic-autic and masterysympathy pairs is acknowledged. Suggestions are made for further research developing and using the resultant measure both within and beyond Reversal Theory