62 research outputs found
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Creative use of BIPV materials: barriers and solutions
Inventive use of photovoltaic (PV) materials in architecture can be developed through use of PV in artworks. This is particularly important in increasing the uptake of building-integrated building-integrated photovoltaics (BIPV), by developing novel methods of combining and installing PV materials. Current examples of PV artwork and design are examined, from small to large scale, to assess the current design limitations. The design of two PV artworks is discussed in detail, including an artwork that uses the principle of the luminescent solar concentrator (LSC), to show the way in which design hurdles are discovered and overcome. Challenges range from difficulties in obtaining small quantities of PV materials; the balance between efficiency and artistic effect; through to technical and siting issues that an artist must address when designing a functional PV structure. Methods of overcoming these barriers are explored, including the use of lumogen dyes in encapsulant materials
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A silicone host for Lumogen dyes
Altering the encapsulant colour in photovoltaic (PV) modules is a straightforward way of achieving greater colour range whilst minimising additional cost in PV systems. Lumogen fluorescent, organic dyes offer a way of adding colour to the encapsulant with minimal change in efficiency. The silicone encapsulant material Sylgard 184 is tested as a host material for Lumogen dyes. A method of dissolving various Lumogen dyes in Sylgard is investigated, and limits of solubility are explored. Methods of preparing samples suitable for optical measurements are found. Optical density is measured for a range of dye concentrations. The results indicate that Lumogen dyes can be dissolved successfully within Sylgard 184, giving good optical properties for lower dye concentrations. Initial photoluminescent quantum yield measurements confirm that Lumogen dyes can function effectively within a Sylgard host. This is promising for use of this material combination in the creation of coloured, fluorescent PV encapsulant layers
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The search for building-integrated PV materials with good aesthetic potential: a survey
Building-integrated photovoltaics (PV) is currently dominated by blue and black rectilinear forms. Greater variety of colour and form could lead to much better uptake of PV in the built environment, also increasing the potential for PV to be used as an artistic material. Listing the available PV technologies by colour gives a clearer picture of the current situation. An assessment of photostability, efficiency and price, for each material, indicates the materials that have the potential to fill the gaps in the colour spectrum. Use of combinations of materials that can be fabricated in different ways from the current, standardised, PV modules will further increase the possibilities for use in building integration, Extending the lifetimes of organic PV, dye-sensitised PV or luminescent solar concentrators will increase the possibilities for development of new PV products
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Improving the aesthetics of photovoltaics through use of coloured encapsulants
Photovoltaics (solar cells) are important in the creation of sustainable architecture, but are difficult to integrate into a wide variety of architectural styles, which is necessary if this technology is to be extensively used. Adding variety to the colour range in these installations will provide a way of making this solar energy technology more visually exciting, so methods need to be found to add colour at minimal extra cost, without loss of efficiency. Adding colour to photovoltaic encapsulant materials offers a solution. It is shown that fluorescent, organic Lumogen dyes (BASF) can be added to the photovoltaic encapsulant materials Sylgard 184 (Dow Corning) and EVA (Ethylene Vinyl Acetate). The dyes continue to fluoresce within these host materials. Encapsulating a photovoltaic cell with Sylgard containing Lumogen red 300 dye (BASF) demonstrates that light can be transported to a photovoltaic cell by the fluorescent dyes inside the encapsulant material that surrounds the cell. This slightly improves the electricity output from the photovoltaic cell, and is especially promising for use in light-transmissive photovoltaic arrays incorporating widely-spaced photovoltaic cells, such as architectural glass art that incorporates photovoltaics. Further work is needed to test and improve the performance of the dyes over time, to ensure that installations incorporating this technology can last for the minimum twenty years that is the current industry standard for photovoltaics
Luminescent solar concentrators: From experimental validation of 3D ray-tracing simulations to coloured stained-glass windows for BIPV
Luminescent solar concentrators (LSC) are a promising technology for building integrated photovoltaics (BIPV) given the wide variety of forms and colours that can be realised. Given the flexibility of the technology, the use of ray-trace modelling is indispensable in the design, performance evaluation, and optimisation of LSCs. This work begins by comparing a three dimensional (3D) ray-trace model of an LSC with experimental results. The study includes 70 samples – both square and circular LSCs, containing five different fluorescent organic dyes (BASF Lumogen) each at seven different concentrations. The figure-of-merit used for performance evaluation was the average power density determined at the LSC edge sheet, measured using an optical fibre connected to a spectrometer. The results demonstrate that 3D ray-trace results gives good agreement with the experimental measurements, to within around ±5% within a wide concentration range (optical density=0.05–8) and a maximum difference of ±13%. The wide range of colours achieved is presented in a CIE chart. Overall, the validated experimental results give confidence in the use of modelling for future larger LSCs for BIPV. Therefore, based on these results and the colours achievable, a model of a stained-glass window is constructed and its performance throughout a solar day is simulated
Towards the development of an automated ATP measuring platform to monitor microbial quality of drinking water
Ecological Assessment of Everyday Executive Functioning at Home and at School using the BRIEF Questionnaire following Childhood Traumatic Brain Injury (TBI)
IntroductionCognitive and behavioural aspects of executive functioning (EF) are frequently impaired following childhood TBI. The Behavior Rating Inventory of Executive Function (BRIEF) questionnaire provides an ecological assessment of EFs in everyday life in home and school environments. The aims of this study were to describe the dysexecutive disorders in children with TBI using the BRIEF; to compare parent- and teacher-ratings and to analyse the demographic and medical variables influencing outcome.MethodsParticipants: Children/adolescents aged 5–17 years 11 months, referred to a paediatric rehabilitation department following TBI. Outcome measures: the parent–and the teacher-report of the BRIEF were collected during neuropsychological assessment (2009–2014), as well as the teacher-report (from 2014). Age at injury and assessment, parental education and TBI severity were collected.Results194 patients (142 boys) participated in the study [mild (n=13), moderate (n=12) or severe (n=169: mean duration of coma 7.2 days; SD=6.5)]. 193 parent-reports and 28 complete teacher reports of the BRIEF were available. Mean age at injury/assessment were 6.9 (SD=4.4), and 11.8 (SD=3.5) years respectively. According to parent-ratings, children had significantly elevated scores in all BRIEF indices [Global Executive Composite (GEC), Behaviour Regulation Index (BRI), Metacognition Index (MI)], and subscales (mean T-scores 61–64; all P<.0001), with 24% to 48.0% scoring in the clinical range. Teachers’ ratings indicated similar deficits in all sub-scales (mean T-scores 63–70; all P<.001), with 39.3–57.2% scoring in the clinical range. For patients with teacher and parent-reports (n=27), no significant difference was found between parent and teacher ratings, which were significantly correlated (r: .44–.72). Regression analyses indicated that GEC was significantly predicted by older age at assessment. The regression model for BRI was not significant. For MI, younger age at injury and older age at assessment were significant predictors.Discussion and conclusionThis study highlights elevated levels of executive dysfunction in everyday life following childhood TBI, evident in home and school environments. Younger age at injury seems to influence the cognitive rather than the behavioural aspects of EFs, whereas older age at assessment is related to higher levels of complaints, probably due to the increasing levels of expectations
Patient and physician satisfaction in an observational study with methyl aminolevulinate daylight-photodynamic therapy in the treatment of multiple actinic keratoses of the face and scalp in 6 European countries
BACKGROUND
Guidelines recommend treating actinic keratoses (AKs) as they are recognized as precursors of invasive squamous cell carcinoma.
OBJECTIVE
The objective of this study was to collect real-world clinical data on the use of methyl aminolevulinate daylight photodynamic therapy (MAL DL-PDT) for the treatment of face and scalp AK in Europe.
METHODS
A prospective, multicenter, non-interventional study was conducted in six European countries in patients receiving a single treatment of MAL DL-PDT for face and/or scalp AK. Patient-reported outcomes were assessed by patient questionnaires at baseline and at 3 months after treatment, efficacy was assessed at 3 months using a 6-point global improvement scale, and adverse events (AE) were recorded at each visit.
RESULTS
Overall, 325 patients were enrolled from 52 investigational centres, 314 of whom attended the 3-month visit. Most patients had multiple lesions (58.4% had >10 lesions) with lesions mainly located on the scalp (60.0%) and/or forehead (54.2%). AKs were predominantly grade I (39.4%) or grade II (33.2%), and 10.5% of patients had grade III lesions. The proportions of patients and physicians that were overall satisfied to very satisfied with the MAL DL-PDT treatment were 80.4% and 90.3%, respectively. The vast majority of patients (90.0%) would consider using MAL DL-PDT again if needed. Physician-assessed efficacy at 3 months was at least much improved in 83.5% of patients, with 45.9% of patients requiring no retreatment. Related AEs were reported in 15% of patients.
CONCLUSION
Use of MAL DL-PDT for multiple face and/or scalp AKs resulted in high levels of patient and physician satisfaction in clinical practice in Europe, reflecting the good efficacy and high tolerability of this convenient procedure
Monitoring of drinking water quality using automated ATP quantification
A microfluidic based system was developed for automated online method for the rapid detection and monitoring of drinking water contamination utilising microbial Adrenosine-5′-Triphosphate (ATP) as a bacterial indicator. The system comprises a polymethyl methacrylate based microfluidic cartridge inserted into an enclosure incorporating the functions of fluid storage and delivery, lysis steps and real-time detection. Design, integration and operation of the resulting automated system are reported, including the lysis method, the design of the mixing circuit, the choices of flow rate, temperature and reagent amount. Calibration curves of both total and free ATP were demonstrated to be highly linear over a range from 2.5–5000 pg/mL with the limit of detection being lower than 2.5 pg/mL of total ATP. The system was trialled in a lab study with different types of water, with lysis efficiency being found to be strongly dependent upon water type. Further development is required before online implementation
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