323 research outputs found
The topographic development and areal parametric characterization of a stratified surface polished by mass finishing
Mass finishing is amongst the most widely used finishing processes in modern manufacturing, in applications from deburring to edge radiusing and polishing. Processing objectives are varied, ranging from the cosmetic to the functionally critical. One such critical application is the hydraulically smooth polishing of aero engine component gas-washed surfaces. In this, and many other applications the drive to improve process control and finish tolerance is ever present. Considering its widespread use mass finishing has seen limited research activity, particularly with respect to surface characterization. The objectives of the current paper are to; characterise the mass finished stratified surface and its development process using areal surface parameters, provide guidance on the optimal parameters and sampling method to characterise this surface type for a given application, and detail the spatial variation in surface topography due to coupon edge shadowing. Blasted and peened square plate coupons in titanium alloy are wet (vibro) mass finished iteratively with increasing duration. Measurement fields are precisely relocated between iterations by fixturing and an image superimposition alignment technique. Surface topography development is detailed with ‘log of process duration’ plots of the ‘areal parameters for scale-limited stratified functional surfaces’, (the Sk family). Characteristic features of the Smr2 plot are seen to map out the processing of peak, core and dale regions in turn. These surface process regions also become apparent in the ‘log of process duration’ plot for Sq, where lower core and dale regions are well modelled by logarithmic functions. Surface finish (Ra or Sa) with mass finishing duration is currently predicted with an exponential model. This model is shown to be limited for the current surface type at a critical range of surface finishes.
Statistical analysis provides a group of areal parameters including; Vvc, Sq, and Sdq, showing optimal discrimination for a specific range of surface finish outcomes. As a consequence of edge shadowing surface segregation is suggested for characterization purposes
P-07 Religiosity and Acceptance of Rape Myths in Conservative Christian College Students
Short AbstractReligiosity and Acceptance of Rape Myths in Conservative Christian College Students JORDANNE HOWELL-WALTON Andrews University (KARL G.D. BAILEY, Faculty Sponsor)
WRITING AS A COMPLETED STUDY
Long Abstract JORDANNE HOWELL-WALTON NATHANEL TCHAMBABETHANY MORRISON
Title: Religiosity and Perceptions of Rape Myth in Conservative College Campuses Area: Social Psychology
Major Purpose Freymeyer (1997) reported a positive correlation between religiosity and the acceptance of rape myth, especially among men who claimed to pray more (1997). Now that 20 years have passed, has the acceptance or rape myth changed for college students attending conservative Christian colleges? The purpose of our study was to examine whether there is a higher acceptance of rape myth in conservative Christian subcultures, especially for individuals who see themselves as being more religious. Twenty years ago, when Freymeyer conducted his study, he looked at religiosity in terms of prayer and other religious actions. We have decided to examine religion not only in actions, but as well as it’s intrinsic value to an individual and how that affects their acceptance of rape myth.
ProcedureWe conducted this study at a conservative Christian college, using 173 subjects collected from an undergraduate research participation pool. Subjects completed two surveys in addition to a demographic questionnaire. The first addressed religious orthodoxy (Religious Orthodoxy Scale; Fullerton, 1982). The second measured rape myth acceptance (Illinois Rape Myth Acceptance Scale; Payne & Fitzgerald, 1999). Subjects completed the scales online through LimeSurvey. Data was analyzed using Pearson’s R looking for a relationship between religiosity and rape myth as a whole. We then used a relative importance metrics within a linear regression to identify which type of rape myths share the most variance with religious orthodoxy.
Results We found the greatest amount of variance was between religiosity and the subscales: rape is trivial, it wasn’t rape, rape is deviant, and she lied.
ConclusionIn conclusion, the relationship between religiosity and the acceptance of rape myth as a whole showed a very small correlation. Some limitations we faced were only using subjects from one conservative college and the IRMA scales were biased in suggesting only women can be victims. Future research should focus on potentially running this study in another university associated with a different religion, or even universities of the same religion in different regions to see if location can also play a role in acceptance of rape myth. Further research into rape myth and culture and religion can help us to see if different subcultures see rape differently.
References
Freymeyer, R.H., (1997). Rape myths and religiosity. Sociological Spectrum 17, 473. doi:10.1177/0886260516665110
Fullerton, J.T., Hunsberger, B.,(1982). A unidimensional measure of christian orthodoxy. Journal for the Scientific Study of Religion, 21, 317-326. doi:10.2307/1385521
Payne, D.L., Lonsway, K.A., Fitzgerald, L.F.,(1999). Rape myth acceptance: Exploration of its measurement using the Illinois rape myth acceptance scale. Journal of Research in Personality, 33, 27-68. doi:10.1006/jrpe.1998.223
A real parametric characterisation of ex-service compressor blade leading edges
In-service the degradation of compressor blade leading edges can have a disproportional effect on compressor efficiency. The high surface curvature in this region makes quantifying the surface finish of this sensitive and prominent region difficult. An automated technique that characterises the roughness of the leading edge in terms of areal parameters is presented. A set of ex-service blades of differing sizes are used to demonstrate the procedure. Improved characterisation of this blade region will allow engine companies to better understand where in-service deterioration has the greatest effect and inform them as to how they might minimise the effect. The present work shows that the leading edges of compressor blades exhibit a significantly higher characteristic surface roughness than other blade regions, and the spatial distribution of peaks in this characteristic roughness is detailed. In addition it is shown that peak wear and roughness are not uniformly correlated
Variable-focus microscopy and UV surface dissolution imaging as complementary techniques in intrinsic dissolution rate determination
This work reports a novel approach to the assessment of the surface properties of compacts used in Surface Dissolution Imaging (SDI). SDI is useful for determining intrinsic dissolution rate (IDR), an important parameter in early stage drug development. Surface topography, post-compaction and post-SDI run, have been measured using a non-contact, optical, three-dimensional microscope based on focus variation, the Alicona Infinite Focus Microscope, with the aim of correlating the IDRs to the surface properties. Ibuprofen (IBU) was used as a model poorly-soluble drug. DSC and XRD were used to monitor possible polymorphic changes that may have occurred post-compaction and post-SDI run. IBUs IDR decreased from 0.033 mg/min/cm2 to 0.022 mg/min/cm2 from 10 to 20 min, respectively, during the experiment. XRD and DSC showed no form changes during the SDI run. The surface topography images showed that a distinct imprint was embossed on the surfaces of some compacts which could affect IDRs. Surface parameter values were associated with the SDI experiments which showed strong correlations with the IDR values. The variable-focus microscope can be used as a complimentary tool in the determination of IDR values from the SDI
MI5 and the Cold War in South-East Asia: Examining the Performance of Security Intelligence Far East (SIFE), 1946-1963
From 1946–1963, MI5 operated a South-East Asian regional headquarters in Singapore: Security Intelligence Far East (SIFE). This article responds to growing interest in theatre-level intelligence organisation and the importance of intelligence to Britain’s Cold War and decolonisation by examining the performance of SIFE. On the organisational level, SIFE was strongest when it remained wedded to its charter functions and closely adhered to the priorities of its principal consumer: the Commissioner-General for South-East Asia. Its assessments were influential in shaping decision-makers’ understandings of key regional developments, although this did not always translate into public policy. Lastly, SIFE enjoyed success in developing lasting liaison relationships to cement British influence, but failed to utilise these to improve its intake of raw intelligence
An investigation of drug compact topography as relates to intrinsic dissolution rates determined by dissolution imaging
Characterisation of wear areas on UHMWPE total knee replacement prostheses through study of their areal surface topographical parameters
Total knee replacement is one of the most common elective surgeries in the world, and presents a number of challenges related to the wear of ultra-high molecular weight polyethylene (UHMWPE). This paper presents an analysis of the surface topographical properties of the worn and unworn condylar surfaces on a small cohort of both wear simulated and retrieved prostheses of varying designs. A number of measurement points were taken on each prostheses in a mixture of worn and unworn areas through the use of focus-variation microscopy (FVM), a non-contact method of surface measurement. Surface areal parameters were extracted from this data to analyse and search for patterns within the data. It was found that in general, worn implant surfaces appear to show smoother, less peak dominated surfaces than unworn area. It was also found that wear simulated and retrieved implants display similar characteristics of surface topography. In addition, variation was noted between different designs of TKR device, with posterior stabilised designs found to be peak dominated and cruciate retaining type implants being valley dominated
A predictive integrated framework based on the radial basis function for the modelling of the flow of pharmaceutical powders
This study presents a modelling framework to predict the flowability of various commonly used pharmaceutical powders and their blends. The flowability models were trained and validated on 86 samples including single components and binary mixtures. Two modelling paradigms based on artificial intelligence (AI) namely, a radial basis function (RBF) and an integrated network were employed to model the flowability represented by the flow function coefficient (FFC) and the bulk density (RHOB). Both approaches were utilized to map the input parameters (i.e. particle size, shape descriptors and material type) to the flow properties. The input parameters of the blends were determined from the particle size, shape and material type properties of the single components. The results clearly indicated that the integrated network outperformed the single RBF network in terms of the predictive performance and the generalization capabilities. For the integrated network, the coefficient of determination of the testing data set (not used for training the model) for FFC was R2=0.93, reflecting an acceptable predictive power of this model. Since the flowability of the blends can be predicted from single component size and shape descriptors, the integrated network can assist formulators in selecting excipients and their blend concentrations to improve flowability with minimal experimental effort and material resulting in the (i) minimization of the time required, (ii) exploration and examination of the design space, and (iii) minimization of material waste
Surface finishing and residual stress improvement of chemical vapour deposited tungsten carbide hard coatings by vibratory polishing
Hard coatings are widely used in several industries to improve the service life of engineering components. W/WC coatings deposited through chemical vapour deposition (CVD) have the capability of providing the required protection on parts with complex geometries, commonly used in high wear and corrosive environments. Despite the improvement in service life, a key important factor is the adherence to low roughness and tolerance specifications, necessitating the need of a post-coating finishing process. In this work the impact of vibratory polishing on W/WC coating was studied using a vibratory barrel setup and two types of ceramic-based media. An improvement in average Ra of 0.2–0.3 μm was achieved over a duration of 4 h with abrasive wear being the predominant polishing mechanism. Insignificant weight loss (<0.017 g) and hardness changes (−2 < ΔHV < 8) were confirmed while the compressive residual stresses of the coating were found to increase with process time (max Δσ = −1058.3 MPa
Calibration of the NuSTAR High Energy Focusing X-ray Telescope
We present the calibration of the \textit{Nuclear Spectroscopic Telescope
Array} (\nustar) X-ray satellite. We used the Crab as the primary effective
area calibrator and constructed a piece-wise linear spline function to modify
the vignetting response. The achieved residuals for all off-axis angles and
energies, compared to the assumed spectrum, are typically better than \%
up to 40\,keV and 5--10\,\% above due to limited counting statistics. An
empirical adjustment to the theoretical 2D point spread function (PSF) was
found using several strong point sources, and no increase of the PSF half power
diameter (HPD) has been observed since the beginning of the mission. We report
on the detector gain calibration, good to 60\,eV for all grades, and discuss
the timing capabilities of the observatory, which has an absolute timing of
3\,ms. Finally we present cross-calibration results from two campaigns
between all the major concurrent X-ray observatories (\textit{Chandra},
\textit{Swift}, \textit{Suzaku} and \textit{XMM-Newton}), conducted in 2012 and
2013 on the sources 3C\,273 and PKS\,2155-304, and show that the differences in
measured flux is within 10\% for all instruments with respect to \nustar
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