Resource efficient plasmon-based 2D-photovoltaics with reflective support

For ultrathin (similar to 10 nm) nanocomposite films of plasmonic materials and semiconductors, the absorptance of normal incident light is typically limited to about 50%. However, through addition of a non-absorbing spacer with a highly reflective backside to such films, close to 100% absorptance can be achieved at a targeted wavelength. Here, a simple analytic model useful in the long wavelength limit is presented. It shows that the spectral response can largely be characterized in terms of two wavelengths, associated with the absorber layer itself and the reflective support, respectively. These parameters influence both absorptance peak position and shape. The model is employed to optimize the system towards broadband solar energy conversion, with the spectrally integrated plasmon induced semiconductor absorptance as a figure of merit. Geometries optimized in this regard are then evaluated in full finite element calculations which demonstrate conversion efficiencies of up to 64% of the Shockley-Queisser limit. This is achieved using only the equivalence of about 10 nanometer composite material, comprising Ag and a thin film solar cell layer of a-Si, CuInSe2 or the organic semiconductor MDMO-PPV. A potential for very resource efficient solar energy conversion based on plasmonics is thus demonstrated

Maximized Optical Absorption in Ultrathin Films and Its Application to Plasmon-Based Two-Dimensional Photovoltaics

For ultrathin films of a given material, light absorption is proportional to the film thickness. However, if the optical constants of the film are chosen in an optimal way, light absorption can be high even for extremely thin films and optical path length. We derive the optimal conditions and show how the maximized absorptance depends on film thickness. It is then shown that the optimal situation can be emulated by tuning of the geometric parameters in feasible nanocomposites combining plasmonic materials with semiconductors. Useful design criteria and estimates for the spatial absorption-distribution over the composite materials are provided. On the basis of efficient exchange of oscillator strength between the plasmonic and semiconductor constituents, a high quantum yield for semiconductor absorption can be achieved. The results are far-reaching with particularly promising opportunities for plasmonic solar cells

Sharing Clinical Notes and Electronic Health Records With People Affected by Mental Health Conditions: Scoping Review

Background: Electronic health records (EHRs) are increasingly implemented internationally, whereas digital sharing of EHRs with service users (SUs) is a relatively new practice. Studies of patient-accessible EHRs (PAEHRs)—often referred to as open notes—have revealed promising results within general medicine settings. However, studies carried out in mental health care (MHC) settings highlight several ethical and practical challenges that require further exploration. Objective: This scoping review aims to map available evidence on PAEHRs in MHC. We seek to relate findings with research from other health contexts, to compare different stakeholders’ perspectives, expectations, actual experiences with PAEHRs, and identify potential research gaps. Methods: A systematic scoping review was performed using 6 electronic databases. Studies that focused on the digital sharing of clinical notes or EHRs with people affected by mental health conditions up to September 2021 were included. The Mixed Methods Appraisal Tool was used to assess the quality of the studies. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Extension for Scoping Reviews guided narrative synthesis and reporting of findings. Results: Of the 1034 papers screened, 31 were included in this review. The studies used mostly qualitative methods or surveys and were predominantly published after 2018 in the United States. PAEHRs were examined in outpatient (n=29) and inpatient settings (n=11), and a third of all research was conducted in Veterans Affairs Mental Health. Narrative synthesis allowed the integration of findings according to the different stakeholders. First, SUs reported mainly positive experiences with PAEHRs, such as increased trust in their clinician, health literacy, and empowerment. Negative experiences were related to inaccurate notes, disrespectful language use, or uncovering of undiscussed diagnoses. Second, for health care professionals, concerns outweigh the benefits of sharing EHRs, including an increased clinical burden owing to more documentation efforts and possible harm triggered by reading the notes. Third, care partners gained a better understanding of their family members’ mental problems and were able to better support them when they had access to their EHR. Finally, policy stakeholders and experts addressed ethical challenges and recommended the development of guidelines and trainings to better prepare both clinicians and SUs on how to write and read notes. Conclusions: PAEHRs in MHC may strengthen user involvement, patients’ autonomy, and shift medical treatment to a coproduced process. Acceptance issues among health care professionals align with the findings from general health settings. However, the corpus of evidence on digital sharing of EHRs with people affected by mental health conditions is limited. Above all, further research is needed to examine the clinical effectiveness, efficiency, and implementation of this sociotechnical intervention

Sensitivity of Colding tool life equation on the dimensions of experimental dataset

In this work, 22 sets of cutting data and tool life for longitudinal turning of steel are analyzed using the Colding equation. When modeling tool life with a limited number of tool performance data points, the model error may be low for these points. Evaluating the model for test points not used when computing the model coefficients may give larger errors for these points. This work proves that the Colding model also provides sufficient precision when modelling data points not being used to create the model, and is therefore a well-functioning instrument for tool life modelling. The results also prove that for the selected data, the precision of the model can be greatly improved when the dimension of the data set is increased from 5 to 10 data points. Above 13 data points the precision improvements are negligible.Проаналізовано 22 набору режимів різання і стійкість інструменту при поздовжньому точінні стали при застосуванні моделі Колдінга. При моделюванні стійкості інструменту при обмеженій кількості даних про робочі характеристики помилка моделі може бути незначною в заданих точках. Оцінка моделі для тестових точок, які не використовуються при обчисленні коефіцієнтів моделі, може показати більші помилки в цих точках. Доведено, що модель Колдінга забезпечує достатню точність при моделюванні даних, що не використовуються для створення моделі, і тому може бути застосована для моделювання періоду стійкості інструменту. Результати також доводять, що для даних, що використовуються, точність моделі може бути значно поліпшена при збільшенні набору точок з 5 до 10, а при збільшенні понад 13 точок поліпшення точності моделювання незначні.Проанализированы 22 набора режимов резания и стойкость инструмента при продольном точении стали с применением модели Колдинга. При моделировании стойкости инструмента при ограниченном количестве данных о рабочих характеристиках ошибка модели может быть незначительной в заданных точках. Оценка модели для тестовых точек, не используемых при вычислении коэффициентов модели, может показать бóльшие ошибки в этих точках. Доказано, что модель Колдинга обеспечивает достаточную точность при моделировании данных, не используемых для создания модели, и поэтому может быть применена для моделирования периода стойкости инструмента. Результаты также доказывают, что для используемых данных точность модели может быть значительно улучшена при увеличении набора точек с 5 до 10, а при увеличении более 13 точек улучшения точности моделирования незначительны

Controlling light-with-light without nonlinearity

According to Huygens' superposition principle, light beams traveling in a linear medium will pass though one another without mutual disturbance. Indeed, it is widely held that controlling light signals with light requires intense laser fields to facilitate beam interactions in nonlinear media, where the superposition principle can be broken. We demonstrate here that two coherent beams of light of arbitrarily low intensity can interact on a metamaterial layer of nanoscale thickness in such a way that one beam modulates the intensity of the other. We show that the interference of beams can eliminate the plasmonic Joule losses of light energy in the metamaterial or, in contrast, can lead to almost total absorbtion of light. Applications of this phenomenon may lie in ultrafast all-optical pulse-recovery devices, coherence filters and THz-bandwidth light-by-light modulators

Characteristics of children with hip displacement in cerebral palsy

<p>Abstract</p> <p>Background</p> <p>Hip dislocation in children with cerebral palsy (CP) is a common and severe problem. The dislocation can be avoided, by screening and preventive treatment of children with hips at risk. The aim of this study was to analyse the characteristics of children with CP who develop hip displacement, in order to optimise a hip surveillance programme.</p> <p>Methods</p> <p>In a total population of children with CP a standardised clinical and radiological follow-up of the hips was carried out as a part of a hip prevention programme. The present study is based on 212 children followed until 9–16 years of age.</p> <p>Results</p> <p>Of the 212 children, 38 (18%) developed displacement with Migration Percentage (MP) >40% and further 19 (9%) MP between 33 and 39%. Mean age at first registration of hip displacement was 4 years, but some hips showed MP > 40% already at two years of age. The passive range of hip motion at the time of first registration of hip displacement did not differ significantly from the findings in hips without displacement.</p> <p>The risk of hip displacement varied according to CP-subtype, from 0% in children with pure ataxia to 79% in children with spastic tetraplegia. The risk of displacement (MP > 40%) was directly related to the level of gross motor function, classified according to the gross motor function classification system, GMFCS, from 0% in children in GMFCS level I to 64% in GMFCS level V.</p> <p>Conclusion</p> <p>Hip displacement in CP often occurs already at 2–3 years of age. Range of motion is a poor indicator of hips at risk. Thus early identification and early radiographic examination of children at risk is of great importance. The risk of hip displacement varies according to both CP-subtype and GMFCS. It is sometimes not possible to determine subtype before 4 years of age, and at present several definitions and classification systems are used. GMFCS is valid and reliable from 2 years of age, and it is internationally accepted.</p> <p>We recommend a hip surveillance programme for children with CP with radiographic examinations based on the child's age and GMFCS level.</p

When Is a Principal Charged With an Agent’s Knowledge?

Question: Detecting species presence in vegetation and making visual assessment of abundances involve a certain amount of skill, and therefore subjectivity. We evaluated the magnitude of the error in data, and its consequences for evaluating temporal trends. Location: Swedish forest vegetation. Methods: Vegetation data were collected independently by two observers in 342 permanent 100-m2 plots in mature boreal forests. Each plot was visited by one observer from a group of 36 and one of two quality assessment observers. The cover class of 29 taxa was recorded, and presence/absence for an additional 50. Results: Overall, one third of each occurrence was missed by one of the two observers, but with large differences among species. There were more missed occurrences at low abundances. Species occurring at low abundance when present tended to be frequently overlooked. Variance component analyses indicated that cover data on 5 of 17 species had a significant observer bias. Observer-explained variance was &lt; 10% in 15 of 17 species. Conclusion: The substantial number of missed occurrences suggests poor power in detecting changes based on presence/absence data. The magnitude of observer bias in cover estimates was relatively small, compared with random error, and therefore potentially analytically tractable. Data in this monitoring system could be improved by a more structured working model during field work.Original publication: Milberg, P., Bergstedt, J., Fridman, J., Odell, G & Westerberg, L., Systematic and random variation in vegetation monitoring data, 2008, Journal of Vegetation Science, (19), 633-644. http://dx.doi.org/10.3170/2008-8-18423. Copyright: Opulus Press, http://www.opuluspress.se/index.ph

Influence of radial depth of cut on entry conditions and dynamics in face milling application

In this study, acceleration of the workpiece is measured for different radial depths of cut and cutting edge geometries. The influence of the radial depth of cut on the dynamical behavior is evaluated in time and frequency domains. The results for different radial depths of cut and cutting geometries are quantified using the root mean square value of acceleration. The outcome of this research study can be used both for the better cutting data recommendations and improved tool design.У даному дослідженні прискорення оброблюваної деталі вимірювали для різних радіальних глибин різання і геометрії ріжучої кромки фрези. Вплив радіальної глибини різання на динамічну поведінку оцінювали в часових і частотних інтервалах. Отримано кількісні результати для різних радіальних глибин і геометрії різання з використанням середньоквадратичного значення прискорення. Результати цього дослідження можуть бути використані для рекомендацій як покращення процесу різання, так і конструкції інструменту.В данном исследовании ускорение перемещения заготовки измеряли для разных радиальных глубин резания и геометрии режущей кромки фрезы. Влияние радиальной глубины резания на динамическое поведение оценивали во временных и частотных интервалах. Получены количественные результаты для различных радиальных глубин и геометрии резания с использованием среднеквадратичного значения ускорения. Результаты этого исследования могут быть использованы для рекомендаций по улучшению как процесса резания, так конструкции инструмента

The head shaft angle is associated with hip displacement in children at GMFCS levels III-V - a population based study

Background:  An increased Head Shaft Angle (HSA) has been reported as a risk factor for hip displacement in children with cerebral palsy (CP) but opinions differ in the literature. The purpose of this study was to re-evaluate the relationship between HSA and hip displacement in a different population of children with CP. Methods:  The Cerebral Palsy Integrated Pathway Scotland surveillance programme includes 95% of all children with CP in Scotland. The pelvic radiographs from 640 children in GMFCS levels III-V were chosen. The most displaced hip was analysed and the radiographs used were those taken at the child’s first registration in the database to avoid the potential effects of surveillance on subsequent hip centration. A logistic regression model was used with hip displacement (migration percentage [MP] ≥40%) as outcome and HSA, GMFCS, age and sex as covariates. Results: The MP was ≥40% in 118 hips with a mean HSA of 164° (range 121–180°) and < 40% in 522 hips with a mean HSA of 160° (range 111–180°). The logistic regression analysis showed no significant influence of age and sex on MP in this population but a high GMFCS level was strongly associated with hip displacement. An increased HSA was also associated with hip displacement, a 10° difference in HSA for children adjusted for age, sex, and GMFCS gave an odds ratio of 1.26 for hip displacement equal or above 40% (p = 0.009) and hips with HSA above 164.5 degrees had an odds ratio of 1.96 compared with hips with HSA below 164.5 degrees (p = 0.002). Conclusion:  These findings confirm that HSA is associated with hip displacement in children in GMFCS levels III-V.Publisher PDFPeer reviewe