38 research outputs found

    Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

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    : The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity > 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

    The influence of relative humidity on adaptive thermal comfort

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    Buildings generate nearly 30% of global carbon emissions, primarily due to the need to heat or cool them to meet acceptable indoor temperatures. In the last 20 years, the empirically derived adaptive model of thermal comfort has emerged as a powerful alternative to fixed set-point driven design. However, current adaptive standards offer a simple linear relationship between the outdoor temperature and the indoor comfort temperature, assumed to sufficiently explain the effect of all other variables, e.g. relative humidity (RH) and air velocity. The lack of a signal for RH is particularly surprising given its well-known impact on comfort. Attempts in the literature to either explain the lack of such a signal or demonstrate its existence, remain scattered, unsubstantiated and localised. In this paper we demonstrate, for the first time, that a humidity signal exists in adaptive thermal comfort using global data to form two separate lines of evidence: a meta-analysis of summary data from 63 field studies and detailed field data from 39 naturally ventilated buildings over 8 climate types. We implicate method selection in previous work as the likely cause of failure to detect this signal, by demonstrating that our chosen method has a 56% lower error rate. We derive a new designer-friendly RH-inclusive adaptive model that significantly extends the range of acceptable indoor conditions for designing low-energy naturally-conditioned buildings all over the world. This is demonstrated through parametric simulations in 13 global locations, which reveal that the current model overestimates overheating by 30% compared to the new one

    Electrically Detected Magnetic Resonance of Donors and Interfacial Defects in Silicon Nanowires

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    We report our work on the characterization by electrically detected magnetic resonance (EDMR) measurements of silicon nanowires (SiNWs) produced by different top-down processes. SiNWs were fabricated starting from SOI wafers using standard e-beam lithography and anisotropic wet etching or by metal-assisted chemical etching. Further oxidation was used to reduce the wire cross section. Different EDMR implementations were used to address the electronic wave function of donors (P) and to characterize point defects at the SiNWs/SiO2 interface. The EDMR spectra of as produced SiNWs with high donor concentration ([P] = 1018 cm−3) show a single line related to delocalized electrons. SiNWs produced on substrates with lower donor concentration ([P] < 1016 cm−3) reveal the doublet related to substitutional P in Si, as well as lines related to interfacial defects such as Pb0, Pb, E', and E'-like. The EDMR spectra of samples produced by metal-assisted chemical etching exposed to post production oxidation reveal a disordered and defective interface and the disappearance of the P related signal. Forming gas annealing, on the other hand, reduces the contribution of interfacial defects and allows a better resolution of the P related doublet

    Electrically Detected Magnetic Resonance of Donors and Interfacial Defects in Silicon Nanowires

    No full text
    We report our work on the characterization by electrically detected magnetic resonance (EDMR) measurements of silicon nanowires (SiNWs) produced by different top-down processes. SiNWs were fabricated starting from SOI wafers using standard e-beam lithography and anisotropic wet etching or by metal-assisted chemical etching. Further oxidation was used to reduce the wire cross section. Different EDMR implementations were used to address the electronic wave function of donors (P) and to characterize point defects at the SiNWs/SiO(2) interface. The EDMR spectra of as produced SiNWs with high donor concentration ([P]= 10(18) cm(-3)) show a single line related to delocalized electrons. SiNWs produced on substrates with lower donor concentration ([P] < 10(16) cm(-3)) reveal the doublet related to substitutional P in Si, as well as lines related to interfacial defects such as Pb(0), Pb, E', and E'-like. The EDMR spectra of samples produced by metal-assisted chemical etching exposed to post production oxidation reveal a disordered and defective interface and the disappearance of the P related signal. Forming gas annealing, on the other hand, reduces the contribution of interfacial defects and allows a better resolution of the P related doublet

    Ten questions concerning statistical data analysis in human-centric buildings research: A focus on thermal comfort investigations

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    Given the large amount of time we spend indoors, designing and operating buildings that are safe, comfortable, and conducive to productivity and well-being is essential. To achieve this goal, in the past decades, research has been conducted to investigate the influence of the indoor environment on occupants. Thermal comfort has been the subject of most investigations in this field. However, despite being a consolidated research topic since the 1920s, statistical practices for analysing thermal comfort data often rely on simplified premises, which may be due to several possible factors (e.g., limited computational capabilities and lack of training). Consequently, important aspects of data analysis are often absent or overlooked. Recent statistics and statistical software advances have provided more options for effectively modelling complex issues. However, properly using these tools requires a solid understanding of statistical analysis, increasing the risk of misuse in practice. This paper presents ten questions highlighting the most critical issues regarding statistical analysis for thermal comfort research and practice. The first four questions provide general perspectives concerning statistical data analysis, while the remaining ones address specific problems related to thermal comfort research, but that can extend to all human-centric research in the built environment. Additionally, the last five questions demonstrate the practical significance of analysis pitfalls (i.e., sampling variability, selection bias, variable selection, clustered/nested observations, and measurement error) through examples with synthetic data. This study provides insights into the current statistical ‘habits’ in thermal comfort research and, more importantly, help researchers better define and conduct their statistical analyses

    Documenting occupant models for building performance simulation: A state-of-the-art

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    The number of occupancy and occupant behaviour models developed for building performance simulation (BPS) has steadily increased for the past four decades. However, their use is still limited in practice. This is partly due to the difficulty in understanding their utility and to the challenges related to their implementation into BPS. Both problems can be attributed to the lack of a framework for their description and communication. In this paper, we fill this gap by introducing a framework to document occupant models, that represents the state-of-the-art of available information on the topic. The framework consists of four blocks (description, development, evaluation, and implementation) and can also be regarded as a guideline to help researchers communicate their models transparently. Based on a systematic review, we verify to which degree existing academic papers on occupant models meet the framework, thus providing a self-critical assessment of the state-of-the-art of occupant models’ documentation

    Collective behavior of block copolymer thin films within periodic topographical structures

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    We perform a systematic study of the effect of adjacent nanostructures on the confinement of block copolymers (BCP) within pre-patterned trenches in 100 nm thick SiO2 films. Asymmetric PS-b-PMMA BCP with a styrene fraction of 0.71, Mn = 67100 are used. When deposited in the form of thin film, these BCP naturally self-organize upon annealing and form a PS matrix with hexagonally packed PMMA cylinders perpendicularly oriented with respect to the substrate. An accurate study of the confinement of this BCP thin film within isolated trenches is performed as a function of their width (80-260 nm). In this specific configuration the confinement of the BCP thin film within the pre-patterned structures has only been partially achieved. The effect of adjacent trenches on the arrangement of the BCP thin film is investigated using parallel trenches periodically distributed on the surface. The effective confinement of the BCP film is strongly modified by the periodicity of the pre-patterned structures
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