Statistical properties of acoustic emission signals from metal cutting processes

Acoustic Emission (AE) data from single point turning machining are analysed in this paper in order to gain a greater insight of the signal statistical properties for Tool Condition Monitoring (TCM) applications. A statistical analysis of the time series data amplitude and root mean square (RMS) value at various tool wear levels are performed, �nding that ageing features can be revealed in all cases from the observed experimental histograms. In particular, AE data amplitudes are shown to be distributed with a power-law behaviour above a cross-over value. An analytic model for the RMS values probability density function (pdf) is obtained resorting to the Jaynes' maximum entropy principle (MEp); novel technique of constraining the modelling function under few fractional moments, instead of a greater amount of ordinary moments, leads to well-tailored functions for experimental histograms.Comment: 16 pages, 7 figure

The International Urban Energy Balance Models Comparison Project: First Results from Phase 1

A large number of urban surface energy balance models now exist with different assumptions about the important features of the surface and exchange processes that need to be incorporated. To date, no com- parison of these models has been conducted; in contrast, models for natural surfaces have been compared extensively as part of the Project for Intercomparison of Land-surface Parameterization Schemes. Here, the methods and first results from an extensive international comparison of 33 models are presented. The aim of the comparison overall is to understand the complexity required to model energy and water exchanges in urban areas. The degree of complexity included in the models is outlined and impacts on model performance are discussed. During the comparison there have been significant developments in the models with resulting improvements in performance (root-mean-square error falling by up to two-thirds). Evaluation is based on a dataset containing net all-wave radiation, sensible heat, and latent heat flux observations for an industrial area in Vancouver, British Columbia, Canada. The aim of the comparison is twofold: to identify those modeling ap- proaches that minimize the errors in the simulated fluxes of the urban energy balance and to determine the degree of model complexity required for accurate simulations. There is evidence that some classes of models perform better for individual fluxes but no model performs best or worst for all fluxes. In general, the simpler models perform as well as the more complex models based on all statistical measures. Generally the schemes have best overall capability to model net all-wave radiation and least capability to model latent heat flux

Severe paraneoplastic hypoglycemia in a patient with a gastrointestinal stromal tumor with an exon 9 mutation: a case report

BACKGROUND: Non-islet cell tumor induced hypoglycemia (NICTH) is a very rare phenomenon, but even more so in gastrointestinal stromal tumors. It tends to present in large or metastatic tumors, and can appear at any time in the progression of the disease. We present herein a case of NICTH in a GIST tumor and report an exon 9 mutation associated to it. CASE PRESENTATION: A thirty nine year-old man with a recurrent, metastatic gastrointestinal stromal tumor presented to the hospital with nausea, dizziness, loss of consciousness, and profound hypoglycemia (20 mg/dL). There was no evidence of factitious hypoglycemia. He was stabilized with a continuous glucose infusion and following selective vascular embolization, the patient underwent debulking of a multicentric 40 cm × 25 cm × 10 cm gastrointestinal stromal tumor. After resection, the patient became euglycemic and returned to his normal activities. Tumor analysis confirmed excessive production of insulin-like growth factor II m-RNA and the precursor protein, "big" insulin-like growth factor II. Mutational analysis also identified a rare, 6 bp tandem repeat insert (gcctat) at position 1530 in exon 9 of KIT. CONCLUSION: Optimal management of gastrointestinal stromal tumor-induced hypoglycemia requires a multidisciplinary approach, and surgical debulking is the treatment of choice to obtain immediate symptom relief. Imatinib or combinations of glucocorticoids and growth hormone are alternative palliative strategies for symptomatic hypoglycemia. In addition, mutations in exon 9 of the tyrosine kinase receptor KIT occur in 11–20% of GIST and are often associated with poor patient outcomes. The association of this KIT mutation with non-islet cell tumor induced hypoglycemia has yet to be established

Sources of acoustic emission during fatigue of Ti-6Al-4V: effect of microstructure

The fundamentals of acoustic emission (AE) analysis of fatigue cracking were applied to Ti-6Al-4V. The effect of microstructure on the characteristics of the AE events generated and the failure mechanisms which produced AE in Ti-6Al-4V were established. Lamellar microstructures generated one to two orders of magnitude more emission than equiaxed microstructures. The combination of larger grain size, more continuous α/β interfaces, more tortuous crack-front geometry, cleavage and intergranular fracture in lamellar microstructures accounts for the greater amount of emission. For lamellar microstructures, most AE events were generated in the upper 20% of the stress range, whereas in equiaxed microstructures, most events were generated at lower stresses. Most AE events were generated during crack opening and also at low stresses. AE events having high level intensities were also generated at stresses other than the peak stress. This is because in titanium alloys, which have both high strength and toughness, AE events are generated from both plastic zone extension and crack extension.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44721/1/10853_2004_Article_BF00542927.pd

Paratextual subversion: Herrera and his poetry in the anotaciones

The year 1580 saw the publication of the Anotaciones a las obras de Garcilaso de la Vega by the critic and poet Fernando de Herrera (c. 1534–97). This study develops previous scholarship on the paratextual strategies employed by Herrera, especially with regard to the inclusion of his own poetry within the Anotaciones. Two Garcilasian sonnets, ‘D’aquella vista pura i ecelente’ (VIII) and ‘Si para refrenar este desseo’ (XII), in conjunction with Herrera’s poetic responses, lie at the heart of this investigation, representing two respectively dominant cultural currents of the period: Neoplatonism and Classical mythography. It will be shown how Herrera exploits Counter-Reformation attitudes towards secularity and mythography to engage in a critique that goes deeper than the attacks previously noted by Navarrete’s 1991 study. Indeed, Herrera’s lyric occupies a central role in a complete re-evaluation of Garcilasian lyric that not only moves to subvert the supremacy of the Toledan but also the hegemonic rule of intellectuals from Castile. Herrera presents himself as a learned Andalusian model for Neoplatonic poetics and as the model for imitation for Spanish letters in the wake of the Counter-Reformation. En 1580 el poeta y crítico Fernando de Herrera (c. 1534–97) publicó sus Anotaciones a las obras de Garcilaso de la Vega. Este artículo desarrolla estudios anteriores sobre esta obra en relación con las estrategias paratextuales empleadas por Herrera, sobre todo por lo que respecta a la inclusión de su propia poesía en el texto de las Anotaciones. Este trabajo se centra en dos sonetos de Garcilaso, ‘D’aquella vista pura i ecelente’ (VIII) y ‘Si para refrenar este deseo’ (XII), en conjunción con otros tantos textos poéticos de Herrera, teniendo en cuenta sus deudas con dos corrientes culturales contemporáneas: el neoplatonismo y la mitología clásica. Las actitudes hacia el amor neoplatónico y la mitología fueron explotadas por Herrera de una manera más profunda de lo que se suele creer. En efecto, la poesía de Herrera ocupa un papel central en la reevaluación completa de Garcilaso que no sólo subvierte la posición del poeta en el canon literario sino también la hegemonía de los intelectuales de Castilla. Herrera se presenta como un andaluz sabio y defensor de la poesía neoplatónica y como el modelo de referencia para la imitación poética en la nueva era que se abre con la Contrarreforma.This is the author accepted manuscript. The final version is available from Maney via http://dx.doi.org/10.1179/1468273715Z.00000000012