Rural Crime and Community Safety

Crime is often perceived as an urban issue rather than a problem that occurs in rural areas, but how far is this view tenable? This book explores the relationship between crime and community in rural areas and addresses the notion of safety as part of the community dynamics in such areas. Rural Crime and Community Safety makes a significant contribution to crime science and integrates a range of theories to understand patterns of crime and perceived safety in rural contexts. Based on a wealth of original research, Ceccato combines spatial methods with qualitative analysis to examine, in detail, farm and wildlife crime, youth related crimes and gendered violence in rural settings. Making the most of the expanding field of Criminology and of the growing professional inquiry into crime and crime prevention in rural areas; rural development; and the social sustainability of rural areas, this book builds a bridge by connecting Criminology and Human Geography. This book will be suitable for academics, students and practitioners in the fields of criminology, community safety, rural studies, rural development and gender studies

Analysis of Rotor-to-Stator Rub in a Large Steam Turbogenerator

Rotor to stator rub is a very common topic in rotor dynamics and several models have been proposed in literature. Anyhow these models are often able to explain only the experimental dynamical behaviour of simple test rigs, which are deliberately reproducing a Jeffcott rotor. On the contrary case histories related to real machines are seldom presented and analyzed. The aim of this paper is to present an actual case history of a large turbo generator unit that was subjected to partial arc rubs. The experimental results are shown and discussed along with the model based diagnostic strategy employed to identify the fault severity and the location of the shaft cross-sections where the heaviest rubs occurred. Comparisons between experimental data and simulated vibrations caused by the identified fault are shown to validate the proposed methodolog

Experimental and Theoretical Application of Fault Identification Measures of Accuracy in Rotating Machine Diagnostics

Model-based diagnostic techniques can be used successfully in the health analysis of rotormachinery. Unfortunately, a poor accuracy of the model of the fully assembled machine, as well as errors in the evaluation of the experimental vibrations caused only by the impending fault, can affect the accuracy of fault identifications. This can make difficult to identify the type of the actual fault as well as to evaluate its severity and its position. This paper shows some methods that have been developed to measure the accuracy of the results obtained with model-based techniques aimed to identify faults in rotating machines. The testing of the capabilities of these methods is carried out using both machine response simulated with mathematical models and experimental data on a real machine. (C) 2003 Elsevier Science Ltd. All rights reserved

Effects of the hot alignment of a power unit on oil-whip instability phenomena

This paper shows the results of the analysis of the dynamic behaviour of a power unit, whose shaft-train alignment was significantly influenced by the machine thermal state, that was affected in operating condition by high subsynchronous vibrations caused by oil-whip instability phenomena. The dynamic stiffness coefficients of the oil-film journal bearings of the generator were evaluated considering the critical average journal positions that caused the instability onsets. By including these bearing coefficients in a mathematical model of the fully assembled machine, the real part of the eigenvalue associated with the first balance resonance of the generator rotor became positive. This paper shows the successful results obtained by combining diagnostic techniques based on mathematical models of journal bearings and shaft train with detailed analyses of monitoring data aimed to investigate the effects of the hot alignment of rotating machines on the occurrence of oil-whip instability onsets

Rural Crime and Community Safety

Crime is often perceived as an urban issue rather than a problem that occurs in rural areas, but how far is this view tenable? This book explores the relationship between crime and community in rural areas and addresses the notion of safety as part of the community dynamics in such areas. Rural Crime and Community Safety makes a significant contribution to crime science and integrates a range of theories to understand patterns of crime and perceived safety in rural contexts. Based on a wealth of original research, Ceccato combines spatial methods with qualitative analysis to examine, in detail, farm and wildlife crime, youth related crimes and gendered violence in rural settings. Making the most of the expanding field of Criminology and of the growing professional inquiry into crime and crime prevention in rural areas; rural development; and the social sustainability of rural areas, this book builds a bridge by connecting Criminology and Human Geography. This book will be suitable for academics, students and practitioners in the fields of criminology, community safety, rural studies, rural development and gender studies

A randomized placebo-controlled pilot study of the efficacy and safety of D-cycloserine in people with chronic back pain.

BACKGROUND: Few effective pharmacological treatment options exist for chronic back pain, the leading cause of disability in the US, and all are associated with significant adverse effects. OBJECTIVE: To determine the efficacy and safety of D-cycloserine, a partial agonist to the N-methyl-D-aspartate receptor, in the treatment of chronic low back pain. METHODS: A total of 41 participants with chronic back pain who met all inclusion and exclusion criteria were enrolled in a double-blind, placebo-controlled randomized pilot trial of D-cycloserine. Treatment was administered orally for six weeks at escalating daily doses of 100 mg, 200 mg, and 400 mg, each for two weeks. The primary outcome measure was back pain intensity using the Numeric Rating Scale (0-10). Secondary measures were back pain-related questionnaires: McGill Pain Questionnaire short form, painDETECT, PANAS, and BDI. The pre-specified analysis was a two-way repeated measures analysis of variance. RESULTS: A treatment difference was observed between groups treated with D-cycloserine and placebo at six weeks of 1.05 ± 3.1 units on the Numeric Rating Scale, with an effect size of 0.4 and p = 0.14. This trend of better chronic back pain relief with D-cycloserine was also observed in the secondary measures. No safety issues were seen. CONCLUSION: The difference in mean pain between the D-cycloserine and placebo groups did not reach statistical significance. However, a clinically meaningful effect size in the magnitude of pain relief was observed with a consistent pattern across multiple outcome measures with good safety, supporting further research into the effectiveness of D-cycloserine for chronic back pain

On the Born-Oppenheimer approximation of diatomic molecular resonances

We give a new reduction of a general diatomic molecular Hamiltonian, without modifying it near the collision set of nuclei. The resulting effective Hamiltonian is the sum of a smooth semiclassical pseudodifferential operator (the semiclassical parameter being the inverse of the square-root of the nuclear mass), and a semibounded operator localised in the elliptic region corresponding to the nuclear collision set. We also study its behaviour on exponential weights, and give several applications where molecular resonances appear and can be well located.Comment: 22 page

Diagnostic Significance of Orbit Shape Analysis and its Application to Improve Machine Faults Detection

The full spectrum analysis of rotating machine vibrations is a diagnostic tool that enables the symptoms of some special types of fault to be clearly detected. The Shape and Directivity Index (SDI) of journal filtered orbits is an additional diagnostic parameter whose evaluation can be combined with the full spectrum analysis. The ellipticity of the filtered orbit, as well as the amplitude and the inclination angle of the major axis of the orbit, are parameters whose analysis can provide important diagnostic information. In order to validate the proposed approach, the vibrations of a large turbine-generator unit that was subjected to rotor-to-stator rubs have been analyzed in this paper. The results of this investigation have been used to update the model of the rotor-system that has been used to identify the location and the severity of the fault. In the paper, the improvements in the accuracy of the fault identification provided by the model updating enabled by the SDI analysis are shown

Steam whirl analysis in a high pressure cylinder of a turbo generator

In this paper steam-whirl instability occurrence and modelling is described. Some weak points in usual modelling and in standard stability criteria are discussed. The motivation of the present study is the case history of asteam turbine that experienced heavy steam-whirl instability though the calculated stability margin was sufficiently high in design conditions. During the electrical load rise of a power plant, the 425 MW steamturbogenerator showed an unstable vibrational behaviour as soon as maximum output power was approached. The combined effect of steam excitation (in bladed rows and in the steam glands) and of low damping in some of the oil film bearings was most likely the main cause of the observed malfunction. A model of the turbogenerator has been set up, the steam-whirl exciting force coefficients and the oil film bearing coefficients have been applied and eigenfrequencies and damping factors have been calculated. In order to check the accuracy of this calculation also another method based on energy balance has been used but very similar values have been obtained, confirming the results of the standard stability evaluation approach. The calculation showed that the machine should have been stable, with a sufficient margin of stability, in design conditions. Therefore the steam-whirl excitation models have been analysed for identifying possible weak points which could justify the discrepancies between experimental behaviour and calculated results

Bivariate Analysis of Complex Vibration Data: an Application to Condition Monitoring of Rotating Machinery

The problem of the robust definition of the acceptance regions in conditionmonitoring of the vibrations of rotatingmachinery is related to the more wide field of the analysis of bivariate data. Traditional parametric techniques and innovative nonparametric methods based on the statistical concept of the data depth are presented and critically examined in the paper. The performances with respect to the robustness in the estimation of the acceptance regions are analysed by means of experimental cases of real rotatingmachinery of a power plant