Review of Non-destructive Testing (NDT) Techniques and their applicability to thick walled composites

A tier 1 automotive supplier has developed a novel and unique kinetic energy recovery storage system for both retro-fitting and OEM application for public transport systems where periodic stop start behaviour is paramount. A major component of the system is a composite flywheel spinning at up to 36,000 rpm (600 Hz). Material soundness is an essential requirement of the flywheel to ensure failure does not occur. The component is particularly thick for a composite being up to 30 mm cross section in some places. The geometry, scale and material make-up pose some challenges for conventional NDT systems. Damage can arise in composite materials during material processing, fabrication of the component or in-service activities among which delamination, cracks and porosity are the most common defects. A number of non-destructive testing (NDT) techniques are effective in testing components for defects without damaging the component. NDT techniques like Ultrasonic Testing, X-Ray, Radiography, Thermography, Eddy current and Acoustic Emission are current techniques for various testing applications. Each of these techniques uses different principles to look into the material for defects. However, the geometry, physical and material properties of the component being tested are important factors in the applicability of a technique. This paper reviews these NDT techniques and compares them in terms of characteristics and applicability to composite parts

Investigation on 252Cf Fission Fragment Tracks in Polycarbonate Detectors

Registration and development of fission fragments emitted from /sup 252/Cf source have been carried out in three different polycarbonate detectors. The detectors have been characterised in terms of bulk etch rate and its behaviour. Maximum etchable cone lengths have been compared with the theoretically computed values. Identification of the fission fragments in terms of their mass and charge has been done with the help of the computer programme 'FFR'

Volumes of cancer surgery for breast, colorectal and ovarian cancer 1992–97: is there evidence of increasing sub-specialization by surgeons?

The ‘Calman–Hine Report’ (1995) recommended that cancer surgery should be limited to ‘high-volume’ consultants. Through an analysis of 5 years of Hospital Episode Statistics for the West Midlands region (1992–1997), we have investigated whether there is evidence of increasing numbers of patients with breast, colorectal or ovarian cancer being treated by high throughput, i.e. sub-specialist surgeons, who carry out more than a threshold level of primary cancer resections annually. The proportion of cases treated by the high-volume breast, colorectal and ovarian cancer surgeons increased annually during the 5 years. The absolute number of consultant firms who undertook breast cancer resections reduced during the 5 years; but the number doing colorectal and ovarian surgery increased. Throughout the 5 years, half of the ovarian cancer resections were carried out by consultant firms who did very few procedures – less than 5 of these procedures annually. The relatively high case-load, the elective nature of breast cancer surgery and an early policy change have undoubtedly facilitated the move towards sub-specialization. The weaker trends for colorectal and ovarian cancer surgery suggest continued monitoring is required to ensure that there is a reduction in the proportion of people treated by surgeons who undertake few cancer resections annually. © 2001 Cancer Research Campaign www.bjcancer.co

LineStacker: A spectral line stacking tool for interferometric data

LineStacker is a new open access and open source tool for stacking of spectral lines in interferometric data. LineStacker is an ensemble of CASA tasks, and can stack both 3D cubes or already extracted spectra. The algorithm is tested on increasingly complex simulated data sets, mimicking Atacama Large Millimeter/submillimeter Array and Karl G. Jansky Very Large Array observations of [CII] and CO(3-2) emission lines, from $z\sim7$ and $z\sim4$ galaxies respectively. We find that the algorithm is very robust, successfully retrieving the input parameters of the stacked lines in all cases with an accuracy $\gtrsim90$\%. However, we distinguish some specific situations showcasing the intrinsic limitations of the method. Mainly that high uncertainties on the redshifts ($\Delta z > 0.01$) can lead to poor signal to noise ratio improvement, due to lines being stacked on shifted central frequencies. Additionally we give an extensive description of the embedded statistical tools included in LineStacker: mainly bootstrapping, rebinning and subsampling. Velocity rebinning {is applied on the data before stacking and} proves necessary when studying line profiles, in order to avoid artificial spectral features in the stack. Subsampling is useful to sort the stacked sources, allowing to find a subsample maximizing the searched parameters, while bootstrapping allows to detect inhomogeneities in the stacked sample. LineStacker is a useful tool for extracting the most from spectral observations of various types.Comment: Resubmitted to MNRAS after referee repor

Magnitude and factors associated with delayed initiation of breastfeeding among mothers who deliver in Mulago hospital, Uganda.

Background: Breastfeeding as a determinant of infant health and nutrition saves up to 1.5 million infant lives annually. Though breastfeeding is mostly universal in sub-Saharan Africa, early initiation of breastfeeding is rarely practiced.Objective: To determine magnitude and factors associated with delayed initiation of breastfeeding among mother-infant pairs who deliver in Mulago hospital.Methods: We carried out a descriptive cross sectional study, where 665 mother-infant pairs were interviewed within 24 hours following delivery; with additional qualitative data collected using focus group discussions to understand reasons for delaying initiation. The data was analysed by identification and coding of themes.Results: In this study, 31.4% mothers delayed initiation of breastfeeding. This was associated with maternal HIV positive status (AOR 2.3; 95% CI 1.3-4.2), inadequate prenatal guidance, (AOR 3.6; 95% CI 1.9-6.8), inadequate professional assistance to initiate breastfeeding (AOR 1.8; 95% CI 1.2-2.8) and caesarean section delivery (AOR 8.6; 95% CI 4.7-16.0). Other reasons were perceived lack of breast milk, need of rest for both mother and baby after labor, and negative cultural beliefs.Conclusion: In Mulago Hospital 1:3 mothers delayed initiation of breastfeeding. The reasons for delayed initiation include; inadequate information during ANC, HIV positive serostatus, caesarian section delivery and negative cultural ideas.Keywords: Breastfeeding, initiation, delayed, HI

Certain Mathieu-type Series Pertaining to Incomplete H-Functions

In the present article, we derive closed integral form expressions for a family of convergent Mathieu type a-series along with its alternating variants, whose terms contain incomplete H-functions, which are a notable generalization of familiar H-function. The results established herewith are very general in nature and provide an exquisite generalization of closed integral form expressions of aforementioned series whose terms contain H-function and Fox-Wright function, respectively. Next, we present some new and interesting special cases of our main results

Home-based versus hospital-based cardiac rehabilitation after myocardial infarction or revascularisation: design and rationale of the Birmingham Rehabilitation Uptake Maximisation Study (BRUM): a randomised controlled trial

Background: Cardiac rehabilitation following myocardial infarction reduces subsequent mortality, but uptake and adherence to rehabilitation programmes remains poor, particularly among women, the elderly and ethnic minority groups. Evidence of the effectiveness of home-based cardiac rehabilitation remains limited. This trial evaluates the effectiveness and cost-effectiveness of homebased compared to hospital-based cardiac rehabilitation. Methods/design: A pragmatic randomised controlled trial of home-based compared with hospital-based cardiac rehabilitation in four hospitals serving a multi-ethnic inner city population in the United Kingdom was designed. The home programme is nurse-facilitated, manual-based using the Heart Manual. The hospital programmes offer comprehensive cardiac rehabilitation in an outpatient setting. Patients: We will randomise 650 adult, English or Punjabi-speaking patients of low-medium risk following myocardial infarction, coronary angioplasty or coronary artery bypass graft who have been referred for cardiac rehabilitation. Main outcome measures: Serum cholesterol, smoking cessation, blood pressure, Hospital Anxiety and Depression Score, distance walked on Shuttle walk-test measured at 6, 12 and 24 months. Adherence to the programmes will be estimated using patient self-reports of activity