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

Correlation of micro and nano–scale defects with WVTR for aluminium oxide barrier coatings for flexible photovoltaic modules

This paper seeks to establish a correlation between surface topographical defects and water vapour transmission rate (WVTR) measured under laboratory conditions for aluminium–oxide (Al2O3) barrier film employed in flexible photovoltaic (PV) modules. Defects in the barrier layers of PV modules causing high WVTR are not well characterised and understood. A WVTR of ~10−1 g/m2/day is sufficient for the most packaging applications, but ≤10−6 g/m2/day is required for the encapsulation of long–life flexible PV modules (Carcia et al., 2010a, 2010b). In this study, surface metrology techniques along with scanning electron microscopy (SEM) were used for a quantitative characterisation of the barrier film defects. The investigation have provided clear evidence for the correlation of surface defect density and the transmission of water vapour through the barrier coating layer. The outcomes would appear to suggest that small numbers of large defects are the dominant factor in determining WVTR for these barrier layers

Wavelength Scanning Interferometery for large area roll to roll metrology applications in photovoltaic manufacturing environment

The wavelength scanning interferometer is currently being applied as a core metrology technology as part of the EU project NanoMend - Nanoscale Defect Detection, Cleaning and Repair for Large Area Substrates ̴500 mm width. NanoMend Project aims to develop technologies that are able to detect and correct micro and nano-scale defects in roll-to-roll produced films in order to improve product performance, yield and lifetime

Adult Survivors of Childhood Sexual Abuse: Forgetting and Remembering

Past research on adult memory for childhood sexual abuse (CSA) has provided support for the phenomenon of forgetting and subsequent recovery of the memories, after a period of time. This phenomenon, however, remains a source of debate and is still not fully understood by researchers and psychological and legal practitioners. The research has provided conflicting evidence about the factors which are thought to lead to CSA forgetting for extensive periods of time, in addition to the processes involved in forgetting, triggering and later remembering of the abuse memories by adult survivors. This study utilised a mixed method to investigate and explore the factors and processes associated with CSA forgetting, triggering and later remembering, in a sample of Australian adult CSA survivors (N = 77). Participants were asked to complete a test booklet, containing the Traumatic Events Questionnaire (TEQ), Symptom Checklist-90-Revised (SCL-90-R), Dissociative Experiences Scale II (DES II), Impact of Events Scale - Revised (IES-R), a scale designed to measure persistence of memory (Loftus), and a scale designed to measure emotional intensity at the time of the abuse and now (Williams). Participants were then asked to participate in a semi-structured interview. Seventy-one participants completed the interview process. Five separate analyses were conducted on the data. Methodological issues, such as the use of retrospective data and corroboration of the abuse were outlined. All participants were asked to provide details about any corroboration they had received that the abuse had occurred. The participants were streamed into one of three categories of forgetting (Always Remembered, n = 28; Partial Forgetting, n = 16; and Extensive Forgetting, n = 33). The first analysis (Stage One Analysis One) examined the factors thought to be associated with CSA forgetting, such as abuse parameters (TEQ), current psychological functioning (SCL-90-R), persistence of memory (Loftus), emotional intensity at the time of the abuse and now (Williams), the trauma response experienced at the time of the abuse (IES-R), and current dissociation (DES II), to determine the significant differences between the three groups. A significant difference was found regarding the age at which the abuse commenced, with the Extensive Forgetting group reporting an earlier age at which the abuse commenced. Significant differences were found on the variable that related to being abused by an aunt or uncle, and on the current experience of hostility (SCL-90-R sub-scale), and on the current levels of anger (Williams Emotional Intensity) experienced by the participants. Significant differences between the groups were also found on two of the Persistence of Memory items, namely clarity of memory and participants' memory of the tastes related to the abuse. Finally, a significant difference was found on the participants' current dissociation levels, with the Extensive Forgetting group reporting higher levels of current dissociation than the other two groups. Statistical profiles for each of the three groups were constructed, based on the mean scores of the SCL-90-R, IES-R and DES II, for use in the Stage Two, Analysis Two, profile comparison. Stage Two, Analysis One, provided a qualitative analysis relating to the experience of always remembering the abuse. The aim of this analysis was to provide a deeper understanding of why some participants (n = 23) did not forget about their abuse, when other participants reported being able to forget for a period of time. The results indicated that participants' responses formed clusters, such as older age at abuse onset, failed dissociative mechanisms, constant reminders, and others. Stage Two, Analysis Two, presented and compared each participant's profile against the statistical profiles constructed in Stage One. The participant's profiles included a summary of their TEQ responses and interview responses, in addition to their Stage One test booklet scores. The comparison was made, firstly, on a specific basis against the mean scores obtained by each category of forgetting, and secondly, on a broader basis, against the score range for each measure of the statistical profile. This was done to determine if there was a "typical" member of each category of forgetting and to investigate the within-group differences. The specific profile comparison demonstrated that there was no "typical" member of any of the three groups, with participants varying widely in their scores and patterns of scores. However, when the profile comparison was broadened to include score ranges, 61% of participants, who always remembered the abuse, 44% of participants who partially forgot the abuse, and 47% of participants who extensively forgot their abuse, matched the profile of a "typical" member of their relevant category of forgetting. Stage Two, Analysis Three, provided an in-depth qualitative exploration on the process involved in CSA forgetting, triggering and later remembering, for a selection of participants who reported partially forgetting the abuse (n = 6), and extensively forgetting the abuse (n = 10). Participants' interview responses were transcribed verbatim and analysed, using Interview Analysis. This analysis explored the differences between participants, from the two categories of forgetting, on their experiences of CSA forgetting, triggering and later remembering, in addition to exploring how these participants were able to forget about the abuse; what events triggered their abuse memories; and how the initial memories returned. Issues of memory recovery, while in therapy or under hypnosis, were also explored. Stage Two, Analysis Four, presented the case study of a participant, who had been identified as an "outlier", due to her high score on the DES II, claims of being able to remember abuse incidents that occurred prior to the age of two years, diagnosis of DID, and the substantiated conviction and sentencing of her abuser, based on her recovered memories of the abuse and corroboration from her sister and mother. Her case was examined against some of the criticisms often made by false memory supporters. This thesis found that some CSA survivors forgot about their abuse, either partially or extensively. The thesis also found support for some, but not all, of the factors that previous researchers have identified as being associated with CSA forgetting by adult survivors, specifically the individual's age at the time the abuse commenced and the individual's ability to dissociate from the abuse. The research then explored, in-depth, the issues of: CSA remembering, CSA survivor profiling, and the "how" of CSA forgetting, triggering and later remembering, by adult survivors

Metrology for Bio Systems

The current paper addresses the advent of next generation bio system focussed Micro Nano Manufacturing Technologies (MNMT). These products and processes have placed significant new emphasis on specification and quality control systems, especially if these product and processes are to achieve economic scale up. Bio technology products and processes are a core element of MNMT and structured surfaces can be a key element in enabling bio system function. There examples of the application of such surfaces in bio systems for functions such as diverse as anti fouling and oseointegration. However a deficit exists in terms of metrology for bio structured surfaces and identifying suitable measurands and instrumentation remains a challenge for production engineers. Functional modelling would seem to point towards a better way of specifying metrology however for bio systems these are rare and often extensive function testing and clinical trials are used to inform the metrology selection. In the present paper the development of MNMT bio systems is discussed in the metrology context and several examples of developing metrology challenges. Four such bio related systems are discussed the solutions are outlined. The case studies cover traditional prosthetic implants, micro fluidic devices, cellular attachment and manufacture of cellular scaffolds

Implementation of in Process Surface Metrology for R2R Flexible PV Barrier Films

Thin functional barrier layers of aluminum oxide (Al2O3) that are used particularly in photovoltaic (PV) modules to prevent the possibility of water vapor ingress should be applied over the entire PV surface without any defects. However, for barrier layer thicknesses within the sub-micrometer range (up to 50 nm) produced through the atomic layer deposition (ALD) method, it is common for defects to occur during the production process. To avoid defective barriers from being incorporated in the final PV unit, defects need to be detected during the barrier production process. In this paper, the implementation of in process inspection system capable of detecting surface defects such as pinholes, scratches, or particles down to a lateral size of 3 μm and a vertical resolution of 10 nm over a 500 mm barrier width is presented. The system has a built-in environmental vibration compensation capability, and can monitor ALD-coated films manufactured using roll-to-roll (R2R) techniques. Ultimately, with the aid of this in process measurement system, it should be possible to monitor the coating surface process of large-area substrates, and if necessary, carry out remedial work on the process parameters

Verification of an in Process Optical System based on High Resolution Interferometry for Detecting Flexible PV Barrier Films Defects

The relationship between surface morphology, defects density and water vapor permeability of aluminium oxide (Al2O3) barrier coating on polyethylene naphthalate (PEN) films, used particularly to prevent water vapor and/or oxygen ingress into flexible photovoltaic (PV) modules has to date been studied in the laboratory. However; detecting defects off-line for flexible PVs is difficult and time consuming, and as such devices are manufactured by R2R methods this procedure can often result in large quantities of barrier films being manufactured before defects are detected. In addition, the quality requirements and line speed are continuously increasing and off-line methods are not efficient to operate within these requirements. Hence, it is desirable to make use of non-contact optical based in-line inspection systems during PV manufacturing processes. Nevertheless, implementing highly accurate in-line (optical) measurement system in the PV production environment can be challenging, as the requirements on positioning and stability are demanding. This research paper reports on the deployment of new in-line interferometric optical technique based on wavelength scanning interferometry (WSI), for detecting PV barriers defects. The instrument has built-in environmental vibration compensation, providing areal measurement at high speed of less than a second per field of view. The technique is being deployed on a demonstrator system at a Roll2Roll production facility as shown in Figure 1. The results show the capability of the WSI to be used as a quality assurance tool in PV production lines, where the results compare favourably with off-line metrology techniques

In-line metrology of functional surfaces with a focus on defect assessment on large area Roll to Roll substrates

This paper reports on the recent work carried out as part of the initial stages of the EU funded NanoMend project. The project seeks to develop integrated process inspection, cleaning, repair for nano-scale thin films on large area substrates. Flexible photovoltaic (PV) films based on CIGS (Copper Indium Gallium Selenide CuInxGa(1-x)Se2) have been reported to have light energy conversion efficiencies as high as 19%. CIGS based multi-layer flexible devices are fabricated on polymer film by the repeated deposition, and patterning, of thin layer materials using roll-to-roll processes (R2R), where the whole film is approximately 3μm thick prior to final encapsulation. The resultant films are lightweight and easily adaptable to building integration. Current wide scale implementation however is hampered by long term degradation of efficiency due to water ingress to the CIGS modules causing electrical shorts and efficiency drops. The present work reports on the use of areal surface metrology to correlate defect morphology with water vapour transmission rate (WVTR) through the protective barrier coatings

Wavelength Scanning Interferometry for PV Production In-line Metrology

Flexible PV modules are manufactured using roll to roll (R2R) technology. These modules require a flexible barrier material to prevent water vapor ingress

Body-related emotional experiences of young Aboriginal women

The purpose of this qualitative case study was to provide insight into the bodyrelated emotional experiences of young Aboriginal women. Four young women took part in this study; three who identified themselves as Aboriginal (one 14-year-old, two 18-year-olds) and one who identified herself as non-Aboriginal (18-year-old). An important strength of this study was that the young women were part of an intact group. The young women were members of a mentorship group at their local high school and this mentorship group was for young women who had faced adversity in their lives.The intent of this study was to listen to the stories and experiences of young women in order to better understand the complex nature of their body-related emotion. Feminist perspective was used to guide the study because it is a voice-centered approach based on listening to women's experiences. Cognitive-Motivational-Relational Theory was used to ground the study because it recognizes that emotion is a complex and context driven process.Through the use of multiple methods (i.e. focus group, one-on-one interviews, artwork) the young women were able to provide an in-depth view of their experiences. Stake's (1995) guidelines for case study data analysis were followed, and the collective story of the young women's body-related emotional experiences have been described. This study contributes to the literature on the body-related emotional experiences of young Aboriginal women in a number of ways. The young women in this study possess many of the positive attributes (i.e. confidence, optimism) that have been associated with resiliency. Also, the emotions that were experienced by the young women were very complex and dependent upon specific contexts. The five themes that emerged from the data were conflicting cultures, need to belong, personal identity, journey to acceptance, and the body affects everything. Overall, the young women in this study noted a general level of body satisfaction, which is inconsistent with previous research surrounding young women's body-related emotion. One of the most important findings from this study is that the body-related emotional experiences of young Aboriginal women are not as negative as previous research has lead us to believe