Plasmonic enhancement of amorphous silicon solar photovoltaic cells with hexagonal silver arrays made with nanosphere lithography

International audienceNanosphere lithography (NSL) provides an opportunity for a low-cost and scalable method to optically engineer solar photovoltaic (PV) cells. For PV application, NSL is widely used in rear contact scenarios to excite SPP and/or high order diffractions, however, the top contact scenarios using NSL are rare. In this paper a systematic simulation study is conducted to determine the capability of achieving efficiency enhancement in hydrogenated amorphous silicon (a-Si:H) solar cells using NSL as a top contact plasmonic optical enhancer. The study focuses on triangular prism and sphere arrays as they are the most commonly and easily acquired through direct deposition or low-temperature annealing, respectively. For optical enhancement, a characteristic absorption profile is generated and analyzed to determine the effects of size, shape and spacing of plasmonic structures compared to an un-enhanced reference cell. The factors affecting NSL-enhanced PV performance include absorption, shielding effects, diffraction, and scattering. In the triangular prism array, parasitic absorption of the silver particles proves to be problematic, and although it can be alleviated by increasing the particle spacing, no useful enhancement was observed in the triangular prism arrays that were simulated. Sphere arrays, on the other hand, have broad scattering cross-sections that create useful scattering fields at several sizes and spacing intervals. For the simulated sphere arrays the highest enhancement found was 7.4%, which was fabricated with a 250nm radius nanosphere and a 50nm silver thickness, followed by annealing in inert gas. These results are promising and provide a path towards the commercialization of plasmonic a-Si:H solar cells using NSL fabrication techniques

SaFiDe: detection of saccade and fixation periods based on eye-movement attributes from video-oculography, scleral coil or electrooculography data

In this work, we present SaFiDe, a deterministic method to detect eye movements (saccades and fixations) from eye-trace data. We developed this method for human and nonhuman primate data from video- and coil-recorded eye traces and further applied the algorithm to eye traces computed from electrooculograms. All the data analyzed were from free-exploration paradigms, where the main challenge was to detect periods of saccades and fixations that were uncued by the task. The method uses velocity and acceleration thresholds, calculated from the eye trace, to detect saccade and fixation periods. We show that our fully deterministic method detects saccades and fixations from eye traces during free visual exploration. The algorithm was implemented in MATLAB, and the code is publicly available on a GitHub repository. The algorithm presented is entirely deterministic, simplifying the comparison between subjects and tasks. Thus far, the algorithm presented can operate over video-based eye tracker data, human electrooculogram records, or monkey scleral eye coil data

‘The Use of Social Media to Foster Trust, Mentorship, and Collaboration in Scientific Organizations

Many domains are well known for their resistance to social media. Currently, there is a dearth of literature that explores social media use in these contexts. This study seeks to help address this gap by evaluating the use of social media within a scientific organization (anonymized as SciCity) that has a strong virtual presence and quarterly face-to-face meet-ups. We evaluated SciCity’s use of social media to foster trust, collaboration, and mentorship. We found that the prominent social media platform Twitter fosters trust among organizational members and plays a role in creating and maintaining lightweight collaborative relationships. Additionally, Twitter-based relationships often act as precursors to collaborations that occur face-to-face. However, Twitter, by itself, was not found to be successful in promoting formal collaborations. Though the medium did facilitate sporadic mentoring, supplementary non-social media-based communication was needed to form mentorship relationships. Twitter was also found to serve as a “social lubricant,” making contact easier and faster, thereby helping foster a scientific social network. Though minor in its role in specifically fostering scientific collaboration, the use of social media by SciCity indicates a shift toward acceptable uses of social media for scientific organizations that have traditionally been hesitant to use social media

Electrochemical degradation of Diclofenac on catalysts based on CNT and M/CNT modified electrodes

Diclofenac (DCF) - a nonsteroidal anti-inflammatory drug - is one of the most frequently detected pharmaceutical compounds in the aquatic environment. Because of its negative effects on public health and environment, this emerging pollutant monitoring and removal from wastewater are of high importance. Electrochemical oxidation has attracted growing interest in the last years, due to its versatility, high efficiency and environment compatibility.Electrochemical oxidation of DCF has been studied using multiwalled carbon nanotubes (CNT) and monometallic catalysts based on carbon nanotubes (M/CNT), at different pH media. The electroreactivity of DCF on modified electrodes and the kinetic parameters of the redox reactions were determined using cyclic voltammetry. Electrodegradation of DCF in aqueous medium was carried out using long-term electrolyses. The products of these electrolyses were identified and quantified by HPLC-MS, GC-MS, HPLC-UV-RID and IC.BioTecNorte (operation NORTE-01-0145-FEDER-000004) and “AIProcMat@N2020 -Advanced Industrial Processes and Materials for a Sustainable Northern Region of Portugal 2020”, NORTE-01-0145-FEDER- 000006, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work also has been funded by national funds (FCT, Fundação para a Ciência e a Tecnologia), through the projects: PTDC/AAGTEC/5269/2014, Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016) and LSRE-LCM (POCI-01-0145-FEDER-006984)info:eu-repo/semantics/publishedVersio

Full-wave modeling of broadband near field scanning microwave microscopy

The authors would like to thank professor Dr. Gabriel Gomila from Institut de Bioenginyeria de Catalunya (IBEC) and Universitat de Barcelona for the fruitful discussion and support, as well as to Dr. Georg Gramse from Johannes Kepler University Linz for the experimental data. B.W. thanks the funding from the China Scholarship Council (CSC) for the support of his research at Queen Mary University of London, UK. Y.H. would like to thank EU-FP7 Nanomicrowave project for the financial support

Effects of web-based electrocardiography simulation on strategies and learning styles

Objective: To identify the association between the use of web simulation electrocardiography and the learning approaches, strategies and styles of nursing degree students. Method: A descriptive and correlational design with a one-group pretest– posttest measurement was used. The study sample included 246 students in a Basic and Advanced Cardiac Life Support nursing class of nursing degree. Results: No significant differences between genders were found in any dimension of learning styles and approaches to learning. After the introduction of web simulation electrocardiography, significant differences were found in some item scores of learning styles: theorist (p < 0.040), pragmatic (p < 0.010) and approaches to learning. Conclusion: The use of a web electrocardiogram (ECG) simulation is associated with the development of active and reflexive learning styles, improving motivation and a deep approach in nursing students

Geriatric oncology: comparing health related quality of life in head and neck cancer patients

Background: Population ageing is increasing the number of people annually diagnosed with cancer worldwide, once most types of tumours are age-dependent. High-quality healthcare in geriatric oncology requires a multimodal approach and should take into account stratified patient outcomes based on factors other than chronological age in order to develop interventions able to optimize oncology care. This study aims to evaluate the Health Related Quality of Life in head and neck cancer patients and compare the scores in geriatric and younger patients. Methods. Two hundred and eighty nine head and neck cancer patients from the Oncology Portuguese Institute participated in the Health Related Quality of Life assessment. Two patient groups were considered: the geriatric ( 65 years old, n = 115) and the younger (45-60 years old, n= 174). The EORTC QLQ-C30 and EORTC QLQ-H&N35 questionnaires were used. Results: Head and neck cancer patients were mostly males, 77.4% within geriatric group and 91.4% among younger patients group. The most frequent tumour locations were similar in both groups: larynx, oral cavity and oropharynx - base of the tongue. At the time of diagnosis, most of younger male patients were at disease stage III/IV (55.9%) whereas the majority of younger female patients were at disease stage I/II (83.4%). The geriatric patient distribution was found to be similar in any of the four disease stages and no gender differences were observed. We found that age (geriatrics scored generally worse), gender (females scored generally worse), and tumour site (larynx tumours denounce more significant problems between age groups) clearly influences Health Related Quality of Life perceptions. Conclusions: Geriatric oncology assessments signalize age-independent indicators that might guide oncologic geriatric care optimization. Decision-making in geriatric oncology must be based on tumour characteristics and chronological age but also on performance status evaluation, co-morbidity, and patient reported outcomes assessment.info:eu-repo/semantics/publishedVersio

Reply to Elmendorf and Ettinger: Photoperiod playsa dominantand irreplaceable role in triggering secondary growth resumption

In their Letter, Elmendorf and Ettinger (1) question the dominant role of photoperiod in driving secondary growth resumption (hereafter referred to as xylem formation onset) of the Northern Hemisphere conifers, recently reported by Huang et al. (2). Their opinions are grounded on the following three aspects, including 1) the seasonality of the photoperiod, 2) the dependence of the predictor variables (e.g., photoperiod, forcing, and chilling) on the response variable (the date of onset of xylem formation, day of the year [DOY]), and 3) the limited value of the obtained models for interannual forecasting. We think they bring up an interesting issue that deserves further discussion and clarification. Photoperiod is acknowledged to regulate spring bud swelling while wood formation starts (3, 4). Although photoperiod seasonality occurs at each site, its influence is marginal in our study given that the analysis involved comparisons among sites across the Northern Hemisphere. Our conclusion that photoperiod plays a dominant role was built upon the combination of several coherent pieces of evidence, rather than “the crux of Huang et al….” as they pointed out. First, we clearly stated that model 2, which modeled DOY as a function of the mean annual temperature of the site (MAT), forcing, chilling, and soil moisture, was considered the best model in terms of parsimony according to minimum Akaike information criterion and Bayesian information criterion, rather than R2 as referred to in their Letter. Second, photoperiod interacted with MAT and can explain 61.7% of the variance of MAT alone (2). Therefore, we concluded that secondary growth resumption was driven primarily by MAT and photoperiod or by their interaction, which is challenging to be disentangled without experimental data, we agree. In terms of biological functioning, they play an ..

Towards the new Thematic Core Service Tsunami within the EPOS Research Infrastructure

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