Emission and Cost Configurations in Earthmoving Operations

Brief introduction to the problem. The paper examines the influence of varying operation parameters such as equipment heterogeneity, payload, and travel times, on unit emissions and unit costs in earthmoving and like operations. The need to minimise cost and maximise production of earthmoving and like operations has led to such operations being heavily scrutinised. With environmental issues becoming more important, there is now a need to additionally scrutinise and minimise emissions. Cycle times and production were measured in a cut-and-fill case study operation; average fuel burn data are converted to idling and nonidling emission fractions; and queuing theory is used for the theoretical evaluation of production for varying operation parameters. It is demonstrated that the optimum fleet sizes in terms of minimum unit costs and minimum unit emissions coincide in earthmoving operations. The result is independent of any specific operational parameters. The paper concludes that the traditional way of undertaking earthmoving operations, namely configuring to give minimum unit costs, will also result in minimum unit emissions. And that configuring differently to that will lead to unnecessary emissions. The result carries over to quarrying and surface mining operations

Vigilantism, Current Racial Threat, and Death Sentences

Capital punishment is the most severe punishment, yet little is known about the social conditions that lead to death sentences. Racial threat explanations imply that this sanction will be imposed more often in jurisdictions with larger minority populations, but some scholars suggest that a tradition of vigilante violence leads to increased death sentences. This study tests the combined explanatory power of both accounts by assessing statistical interactions between past lynchings and the recent percentage of African Americans after political conditions and other plausible effects are held constant. Findings from count models based on different samples, data, and estimators suggest that racial threat and lynchings combine to produce increased death sentences, but the presence of liberal political values explains the absence of death sentences. These findings both confirm and refine the political version of conflict theory because they suggest that the effects of current racial threat and past vigilantism largely directed against newly freed slaves jointly contribute to current lethal but legal reactions to racial threat

Coherent generation of EPR-entangled light pulses mediated by a single trapped atom

We show that a single, trapped, laser-driven atom in a high-finesse optical cavity allows for the quantum-coherent generation of entangled light pulses on demand. Schemes for generating simultaneous and temporally separated pulse pairs are proposed. The mechanical effect of the laser excitation on the quantum motion of the cold trapped atom mediates the entangling interaction between two cavity modes and between the two subsequent pulses, respectively. The entanglement is of EPR-type, and its degree can be controlled through external parameters. At the end of the generation process the atom is decorrelated from the light field. Possible experimental implementations of the proposals are discussed.Comment: 11 pages, 4 figure

Relationship between childhood trauma and paranoia: a study of specificity and underlying theoretical mechanisms

Purpose: While biogenetic theories have traditionally dominated understandings of psychosis, there is now a large body of evidence suggesting a causal relationship between childhood trauma and psychosis. We sought to further study this relationship by adopting a psychotic experience specific approach and applying two of Bradford Hill’s causality criteria, namely specificity and underlying theoretical mechanisms, to the relationship between childhood trauma and paranoia. Method: Chapter 1 was a systematic review and meta-analysis that sought to examine the magnitude of the association between childhood sexual (CSA), physical (CPA) and emotional abuse (CEA) and physical (CPN) or emotional neglect (CEN) and paranoia across community and clinical samples. Chapter 2 is an empirical research study that sought to test whether negative core schema mediated the relationship between childhood trauma and paranoia. Study 1 sought to these relationships within the general population, whereas Study 2 aimed to test these in a clinical sample of people with persecutory delusions. We also sought to pilot a new measure of negative core schema, The Schema Rating Scale (SCIRATS). Correlation and mediation analysis were utilised to test our empirical study hypothesis. Results: Our meta-analysis found small associations between all forms of childhood trauma and paranoia examined, however the magnitude of the association may be somewhat greater for CEA and CPA than for the other forms of childhood we examined and paranoia . In Study 1, we found that negative-self, negative-other and both negative-self and negative-other core schema mediated the relationship between childhood trauma and paranoia. We found similar results when repeating these analyses with the SCIRATS. In Study 2, we found significant associations between childhood trauma and negative-self core schema that remained significant on the SCIRATS. Negative-self and negative-other core schema were also significantly associated with paranoia however, when we repeated this analysis with the SCIRATS, only negative-self core schema remained significant. We found no significant association between childhood trauma and paranoia. Positive initial feedback on the SCIRATS would suggest participants view this as an acceptable measure. Conclusions: Whilst acknowledging the limitations associated with our studies, our findings suggest that while there appears to be a general association between the forms of childhood trauma we examined and paranoia, this relationship may be somewhat greater for CEA and CPA and paranoia. They are consistent with cognitive models of psychosis and suggest that negative core schema may be important underlying mechanisms in the relationship between childhood trauma and paranoia. We make recommendations for future research to further examine the evidence for specificity and recommend that individuals with psychosis should be asked about childhood trauma and that future research should further examine the potential benefits of trauma-informed formulation and psychological therapies targeting negative core schema in reducing paranoia

Who Survives on Death Row? An Individual and Contextual Analysis

What are the relationships between death row offender attributes, social arrangements, and executions? Partly because public officials control executions, theorists view this sanction as intrinsically political. Although the literature has focused on offender attributes that lead to death sentences, the post-sentencing stage is at least as important. States differ sharply in their willingness to execute and less than 10 percent of those given a death sentence are executed. To correct the resulting problems with censored data, this study uses a discrete-time event history analysis to detect the individual and state-level contextual factors that shape execution probabilities. The findings show that minority death row inmates convicted of killing whites face higher execution probabilities than other capital offenders. Theoretically relevant contextual factors with explanatory power include minority presence in nonlinear form, political ideology, and votes for Republican presidential candidates. Inasmuch as there is little or no systematic research on the individual and contextual factors that influence execution probabilities, these findings fill important gaps in the literature

A Comparative Study of Collegiate Aviation Students and Business Students Related to Myers-Briggs Type Indicator Preferences

There has been limited research to date that addresses the difference, if any, between students who choose the various fields of aviation as a major, and those who choose other majors, particularly business. This study utilizes the Myers-Briggs Type Indicator (MBTI) to compare preferences of aviation majors to business majors because of its unique characteristics and its noted lack of use in the aviation arena. The findings of the study revealed that there are no significant differences between business and aviation students in the Myers-Briggs Type Indicators except in the way they orient themselves in the environment (Judging and Perceiving). These findings are a reminder to teachers of aviation students that classroom structure should balance discussion, practice skills, fun and other activities with learning objectives to accommodate the dominant styles of aviation learners. On the other hand, the predominant Judging style of business students would demand that classroom discussion be somewhat limited in order to meet specific learning goals. Maintaining a balance of teaching style is important both for the teacher and the student in reducing the discomfort of the teacher operating outside a preferred style and eliminating the mental stress of the student attempting to learn new material while using an auxiliary type

Evidence base for health and planning – lessons from an ESRC seminar series

The article looks at the lessons on the health and planning evidence base, evidence-sharing and integration that have been emerging from an ESRC seminar series on reuniting health and planning bringing together academics and planning and public health professionals