Laser-Based Ultrasound for the Inspection of Gas Pipelines

Ultrasonics has proven to be an effective method for detecting a variety of defects in gas transmission pipes including cracks, wall thinning and corrosion pits. The use of Lamb waves for the detection of defects and in situ process monitoring applications has been successfully pursued for many years [1–6]. The use of a laser-based ultrasound (LBU) inspection technique to detecti defects is attractive because of the potential for rapid inspection of large areas and because it is noncontact with large standoff distances. Owing to its noncontacting and remote nature, the LBU technique is being investigated as an alternative technology to piezoelectric transducers or electromagnetic acoustic transducers (EMATs) for the rapid nondestructive inspection of pipelines. Currently, the preferred methods for introducing ultrasonic waves into the pipe are by using a piezoelectric transducer in a liquid-filled wheel or an EMAT. In field use, the wheel or the EMAT is attached to a moveable platform (known as a pig), which travels along the length of the transmission line. The wheel must maintain contact with the pipe wall during the inspection. Although the EMAT is a noncontact sensor, it must be operated close to the pipe’s surface. The contact and near-contact requirements can result in a loss of data when pipe irregularities such as dents or joints between sections cause the wheel or the EMAT to lift off from the surface of the pipe. The liquid-filled wheel uses longitudinal waves that propagate into the wall of the pipe. For a complete inspection of the pipe’s circumference, many wheels must be used. The EMAT generates a Lamb wave in the wall of the pipe that can be directed either circumferentially or axially along the pipe. Although the LBU technique also uses Lamb waves, unlike EMAT systems, the detection sensitivity of the LBU system does not decrease with increased separation from the part. However, a potential difficulty for LBU techniques is that Lamb waves are a family of guided waves that exist in plate-like structures, and a large number of modes of vibration may coexist in a given plate thickness. A laser that has been focused to a spot or line represents a broadband Lamb wave source in both the temporal and spatial frequency domains, which leads to the simultaneous excitation of many modes. Consequently, LBU techniques for generating Lamb waves have generally been pursued only when the lowest order symmetric or asymmetric mode was needed, probably because these modes are generated and detected with the greatest efficiency and thus offer a de facto mode selection mechanism since these modes dominate the others that may be present. We previously demonstrated [7] a mechanism for efficiently generating and selecting a single Lamb wave mode using simulated arrays. In this paper, we describe the implementation of a laser array for the generation of Lamb waves. We also present some preliminary results of a study of the characteristics of Lamb wave modes to identify suitable modes for detecting defects in pipelines. The features that are important include the generation and detection efficiency of the Lamb wave modes, the mode’s energy distribution, and the velocity dispersion of the waves

Depression and loneliness in Jamaicans with sickle cell disease

<p>Abstract</p> <p>Background</p> <p>Sickle cell disease (SCD) is the commonest genetic disorder in Jamaica, and has life-long implications for those afflicted with it. It is well known that depression and loneliness may exist in those with chronic diseases, but the coexistence of depression and loneliness in people with sickle cell disease is not clear. The aim of this study is to determine the prevalence of and factors associated with depression and loneliness in the Jamaica Sickle Cell Cohort Study and its age and sex matched controls.</p> <p>Methods</p> <p>277 patients with SCD and 65 controls were administered a questionnaire that studied demographics, disease severity, depression, and loneliness. Regression analyses were done to examine relationships between outcomes and associated variables.</p> <p>Results</p> <p>Depression was found in 21.6% of patients and 9.4% in controls. Loneliness scores were also significantly higher in patients (16.9 ± 5.1) than in controls (14.95 ± 4.69). Depression was significantly associated with unemployment [OR = 2.9, p-value: < 0.001], whereas unemployment (p-value: 0.002), and lower educational attainment were significantly associated with loneliness.</p> <p>In patients with SCD, depression was significantly associated with being unemployed (OR 2.4, 95% CI 1.2,4.6, p-value:0.01), presence of a leg ulcer (OR = 3.8, 95% CI: 1.7, 8.4, p-value: 0.001), frequent visits (OR = 3.3, 95% CI: 1.2, 8.9, p-value: 0.019), and frequent painful crises (OR = 2.5, 95% CI: 1.1, 5.8, p-value: 0.035). Not being employed (Coef.: 2.0; p-value: 0.004) and higher educational attainment (tertiary vs. primary education, Coef.: -5.5; p-value: < 0.001) were significant associations with loneliness after adjusting for genotype.</p> <p>Conclusions</p> <p>Health workers need to actively look for and manage these problems to optimize their patients' total biopsychosocial care.</p

The significance of dynamic dysfunction of critically short telomeres in directing the evolution of chromosomal structural instability in human cells undergoing immortalization

Nonrandom patterns of chromosomal aberrations are universally observed in all types of cancers as well as immortalized cell lines, for which the mechanism of initiation and progression is unknown. To examine whether dynamic telomere dysfunction contributes to the initiation and evolution of the preferential chromosomal aberrations during cellular immortalization, we developed a new technique which allowed, for the first time, telomere quantitative FISH and 24-colour spectral karyotyping in the same human cells. Two human ovarian surface epithelial cell lines (HOSE6-3, HOSE11-12), two esophageal cell lines (NE1-E6E7, NE6-E6E7), and one nasopharyngeal cell line (NP460-E6E7) immortalized by expression of HPV16 E6E7 oncogenes, were studied. We detected striking consistent differences in telomere signal intensities between homologous chromosomes and among non-homologous chromosomes in all five cell lines. The cell lines established from specimens from different donors had different distributions of the shortest telomeres. During cellular aging in vitro, chromosomes with the shortest telomeres were the first to show increased frequencies of chromosomal structural aberrations including dicentrics, translocations, insertions, deletions and duplications, independent of cell lines and cell types. With further cell proliferation towards crisis, progressive increases in frequencies of chromosomal structural aberrations occurred preferentially on specific chromosomes that had increasing frequencies of signal-free telomeres. None of analyzed pre-crisis or crisis metaphases had completely identical aberrations. In post-crisis (immortalized) cells, the majority of clonal stable aberrations again involved the chromosomes with signal-free telomeres before and during crisis. The existence of clonal aberrations in post-crisis cells demonstrates that chromosomes in post-crisis cells are far more stable than those during crisis. Parallel to this, the frequencies of chromosomal ends with undetectable telomeres dropped dramatically in post-crisis cells. Taken together, this study showed that the dysfunction of critically short telomeres played a fundamental role in directing the evolution of chromosomal structural instability leading to formation of nonrandom chromosomal aberrations in human cells undergoing immortalization, and this phenomenon appeared to be independent of cell lines and cell-types

Shanghai Central: A City in Search of a CBD

The automotive industry is increasingly interested in using adhesive bonding in the construction of body shell assemblies. Adhesive joints offer some significant potential advantages over conventional welding techniques, including improved strength and stiffness, greater flexibility in designs, and reduced costs. The NDE requirements associated with the introduction of adhesive bonding include the confirmation during construction that the dimensions of the adhesive in the joint are within specified tolerances. In the common case of a lap joint, illustrated in Figure 1, the key dimensions are the bond thickness and the overlap length

Longitudinal growth during infancy and childhood in children from Shanghai: Predictors and consequences of the age at onset of the childhood phase of growth

The age at onset of the childhood phase of growth, normally occurring between 6 and 12 mo, is recognized to be an important time during postnatal human development. The aims of this present work were to identify predictors for the age at onset of the childhood phase of growth. Furthermore, this work aimed to examine the consequences that this timing would have on the subsequent heights of 1720 Shanghai children. The mean age of the infants at onset of the childhood phase of growth was 11.2 mo in boys and 10.7 mo in girls. Compared with their Swedish counterparts, these means occurred 1.3 mo later in boys and 1.4 mo later in girls. Both age at onset of the childhood phase of growth and length at 6 mo of age significantly (p < 0.05) contributed to the attained height from 12 mo of age onward; 1-mo delay in the onset of the childhood phase of growth reduced height at 5 y of age by 0.4 cm in boys and 0.5 cm in girls. The age at onset of the childhood phase of growth was negatively associated (p < 0.001) with mid-parental height, although positively related (p < 0.001) to height at 6 mo of age. There was a distinct body mass index pattern of Chinese children between birth and 6 y of age in comparison with white values. There was a sharp increase in body mass index in Shanghainese during their first 6 mo of life, followed by a gradual decline up to 24 mo. In conclusion, the age at childhood onset is equally important when studying children from Shanghai as it is with their Swedish counterparts.link_to_subscribed_fulltex

Avaliação do cuidado prestado a pacientes diabéticos em nível primário Assessment of diabetic patient management at primary health care level

OBJETIVO: Descrever características de pacientes diabéticos acompanhados em um posto de atenção primária à saúde. MÉTODOS: Estudo transversal. Rastrearam-se 3.024 prontuários de família, em busca de pacientes com 30-75 anos, com diagnóstico de diabetes, atendidos nos últimos cinco anos. Os pacientes detectados foram entrevistados em seus domicílios, e compareceram ao posto para o exame físico e requisição para dosagem da hemoglobina glicosilada. RESULTADOS: A prevalência de diabetes foi de 4,2%. A maioria eram mulheres brancas, ±50 anos de idade, com renda familiar mensal <= 3 salários-mínimos. Menos de um terço seguia dieta; e, apenas um quinto fazia exercícios regulares. Cerca de 70% estavam em uso de hipoglicemiantes orais ou insulina. Dos que fizeram o exame (adesão de 70%), a maioria apresentou níveis normais ou aceitáveis de glicemia. CONCLUSÕES: Maior esforço deve ser dispendido pelas equipes de saúde de forma a promover a adesão dos pacientes diabéticos à dieta e ao exercício.<br>OBJECTIVE: The characterization of diabetic patients seen at a primary health care clinic. METHODS: The case notes of 3,024 families were searched by means of a cross-sectional study for patients 30 to 75 years of age with a diagnosis of diabetes mellitus who had had a medical consultation during the previsous five years. These patients were interviewed at their homes and were asked to come to the health center for physical examination and a plasma glucose test using glucosylated hemoglobin (GH). RESULTS: The prevalence of diabetes was 4%. The typical diabetic patient was a white women, ±50 years of age, from a family with a monthly income <= 3 minimum wages. Compliance with GH was observed in 70% of the patients. Diet therapy was followed by less than one third of the patients and only one fifth were engaged in regular exercise. Nearly 70% were undergoing drug therapy (oral hypoglicemic agents or insulin); of these, only 15% used insulin. Most of the patients (66%) who agreed to have the GH test showed normal or fair glucose blood levels. CONCLUSIONS: Great efforts should be made by health teams to enhance diabetic patient education in order to promote compliance with recommendations regarding diet and exercise