cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The teacher as street-level bureaucrat: science teacher’s discretionary decision-making in a time of reform
Creators: name: Hall, M.
name: Hampden-Thompson, G.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Biotechnology
subject: Sociology
subject: FOS: Sociology
subject: Developmental Biology
subject: Cancer
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: 110309 Infectious Diseases

description: This article explores teacher discretion in the context of the English 2014 science curriculum and assessment reforms. The study positions primary and secondary school science teachers as “street-level bureaucrats” in which they are not just mere implementers of policy but instead pivotal actors with much agency. Through the analysis of questionnaire and interview data drawn from a sample of 26 science teachers in England, this empirical research advances our understanding of teachers’ discretionary decision-making considering policy change and reform. The findings indicate that discretion varied, not simply between the secondary and primary sectors, but within each key stage. With the introduction of the new curriculum, secondary teachers expressed higher levels of autonomy and more discretion teaching key stage 3 than with key stage 4 and key stage 5. Despite this, we argue that it has become more difficult for teachers to circumvent the “rules” associated with the attainment measures in the ways that were previously possible. We conclude that the embodiment of teachers as street-level bureaucrats is not perfect as the boundaries around teacher’s discretion and decision-making are heavily dependent on the school and national policy context, but it remains a useful theory in advancing our understanding of teacher.
Specialist LINK and primary care network clinical pathways - a new approach to patient referral: a cross-sectional survey of awareness, utilization and usability among family physicians in Calgary
Creators: name: Arain, Mubashir
name: Rostami, Mahnoush
name: Zaami, Mariama
name: Kiss, Valerie
name: Ward, Richard
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Health services and systems

description: Background Specialist LINK is a real-time, non-urgent telephone collaboration line designed to link family doctors and specialists. The purpose was to reduce wait times, improve efficiency and enhance the coordination of patient care through enhanced communication between primary and specialty care. The aim of this study was to determine the awareness and utilization of Specialist LINK and Primary Care Network (PCN) Clinical Pathways among family physicians. Methods A family physician experience cross-sectional survey was conducted from March to May 2018 in Calgary and Area. The survey was designed to assess family physicians’ awareness and utilization of Specialist LINK and PCN Clinical Pathways. We also used a 1–10 scale for respondents to rate the utility of Specialist LINK (1 was least useful and 10 represented highly useful). To obtain a true representative sample, family physicians were selected through a random sampling method. We applied multiple approaches to ensure a high response rate: paper survey, telephone reminders, and an on-site survey for non-responders. Results A total of 251 participants completed the survey of the 650 randomly selected family physicians (Response rate≈39%). Eighty-nine percent of the family physicians were aware of Specialist LINK [95% Confidence Interval (84–92%)]. The average rating was 8.1 (on a scale of 1–10) for the usefulness of Specialist LINK. We found that the odds of being aware of Specialist LINK were two times higher in female family physicians compared to male physicians. Also, those with less than 5 years of experience, the odds of being aware of Specialist LINK were around five times higher compared to those with 5 or more years of experience. Fifty-five percent of family physicians were aware of PCN Clinical Pathways (95% CI = 48–60%); of those, 82% were accessing and following PCN Clinical Pathways in their clinical practice. The average rating was 7.9 (on a scale of 1–10) for the usefulness of PCN Clinical Pathways. Conclusion Most of the respondents in Calgary and area were aware of Specialist LINK and a large proportion of them were using it to access advice for their patients.Other Information Published in: BMC Family Practice
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1186/s12875-020-01159-0
Disaster Risk Reduction and the Social Determinants of Health
Creators: name: CUTHBERTSON, JOSEPH LUKE
Publisher: name: Monash University
Year: 2023
Subjects: Public health not elsewhere classified

description: Disaster risk reduction encompasses practices that reduce exposure to hazards and decrease vulnerability of people and the environment. Such practices are founded on systematic efforts to identify and analyse the causal factors of disasters, rather than apply response designed actions post event. These initiatives represent close alignment with public health practice; further examination of this alignment may assist in strengthening disaster risk reduction and management planning. This PhD examined how the outcomes of disaster events upon an individual and/or a community is related to their underlying determinants of health. The assessment of the relationship of proposed strategies and the Social Determinants of Health facilitated by this PhD provides insight to an improved, holistic approach to disaster practice.
Assessing the risk of angiotensin receptor blockers on major cardiovascular events: a systematic review and meta-analysis of randomized controlled trials
Creators: name: Wanas, Yara
name: Bashir, Rim
name: Islam, Nazmul
name: Furuya-Kanamori, Luis
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Cardiovascular medicine and haematology

description: Background Angiotensin receptor blockers (ARBs) are commonly used as a treatment for many cardiovascular diseases, but their safety has been called into question. The VALUE trial found an increased risk of myocardial infarction in participants receiving ARBs compared to other antihypertensive. The aim of the meta-analysis was to synthetize the available evidence of randomised controlled trials (RCTs) and elucidate if ARBs increase the risk of cardiovascular events. Methods A comprehensive search was conducted to identify RCTs that assessed the safety of ARBs. Titles and abstracts of all papers were independently screened by two authors. Data extraction and quality assessment were also performed independently. The relative risk (RR) of all-cause mortality, myocardial infarction, and stroke were pooled using the IVhet model. Multiple sensitivity analyses were conducted to assess the effect of ARBs by restricting the analysis to different participants’ characteristics. Results Forty-five RCTs comprising of 170,794 participants were included in the analysis. The pooled estimates revealed that ARBs do not increase the risk of all-cause mortality (RR 1.00; 95%CI 0.97–1.04), myocardial infarction (RR 1.01; 95%CI 0.96–1.06), and stroke (RR 0.92; 95%CI 0.83–1.01). The sensitivity analysis did not yield a particular group of patients at increased risk of cardiovascular events with ARBs. Risk of all-cause mortality and stroke decreased with ARB when the proportion of smokers in a population was < 25% (RR 0.91; 95%CI 0.84–0.98) and in females (RR 0.76; 95%CI 0.68–0.84), respectively. Conclusions ARBs do not increase the risk of major cardiovascular events and are safe for use in patients.Other Information Published in: BMC Cardiovascular Disorders
 License: http://creativecommons.org/licenses/by/4.0/
See article on publisher's website: http://dx.doi.org/10.1186/s12872-020-01466-5
Amorphous Silicon-Free Metal-Oxides Based Carrier-Selective Contacts to Crystalline Silicon Solar Cells
Creators: name: Patwardhan, S.
name: Maurya, S.
name: Kumar, A.
name: Balasubramaniam, K.R.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Heterojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 657-659
description: Heterojunction carrier selective contact silicon solar cells are fabricated on both, Czochralski and Float-zone silicon wafers. Molybdenum trioxide and titanium dioxide are used as hole and electron selective layers respectively. The main intention of this work is to achieve dopant-free heterojunction solar cells without using intrinsic amorphous silicon passivation and any traditional anti-reflecting coating. Both the metal oxides are tested for their carrier selectivity and surface passivation. Maximum temperature used during entire cell fabrication process was 150°C. The total number of steps involved are limited to seven. The techniques used are well suited for large area fabrication over an industrial scale. Since this route avoids use of toxic and flammable gases, it results in low overall budget, which otherwise involves critical maintenance and safety measures for these gases. Preliminary results are promising showing ~ 8.7% active area efficiency at 1 Sun simulated radiation. Short circuit current density for the best cell exceeded 31 mA/cm2 with open circuit voltage ~ 514 mV. This route has a potential to become a truly cost-effective, low thermal budget, simple and toxic gases-free process for Si cell production without losing on the current efficiency levels achieved.
Effect of bremsstrahlung radiation emission on fast electrons in plasmas
Creators: name: Embréus, Ola
name: Stahl, Adam
name: Fülöp, Tünde
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Bremsstrahlung radiation emission is an important energy loss mechanism for energetic electrons in plasmas. In this paper we investigate the effect of spontaneous bremsstrahlung emission on the momentum-space structure of the electron distribution, fully accounting for the emission of finite-energy photons. We find that electrons accelerated by electric fields can reach significantly higher energies than what is expected from energy-loss considerations. Furthermore, we show that the emission of soft photons can contribute significantly to the dynamics of electrons with an anisotropic distribution.
description: 5 pages, 3 figures
Rational synthesis, characterization, and application of environmentally friendly (polymer–carbon dot) hybrid composite film for fast and efficient UV-assisted Cd2+ removal from water
Creators: name: Jlassi, Khouloud
name: Eid, Kamel
name: Sliem, Mostafa H.
name: Abdullah, Aboubakr M.
name: Chehimi, Mohamed M.
name: Krupa, Igor
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Pollution and contamination

description: Background Carbon dots (CDs) are of particular interest in numerous applications. However, their efficiency for heavy metal removal from wastewater was not yet reported. Herein, we rationally synthesized CDs from petroleum coke waste via hydrothermal treatment in the presence of ammonia. Results This drove the formation of outstanding photoluminescent, water-soluble, biocompatible, and high yield of monodispersed sub-5 nm CDs. The CDs are co-doped with high 10% of N and 0.2% of S. The as-prepared CDs possess unprecedented photoluminescent properties over broad pH range making these dots unique efficient pH sensor. Conclusions Chitosan (CH)–CDs hybrid hydrogel nanocomposite film was further prepared as a platform membrane for the removal Cd2+ metal from wastewater. The as-prepared CH–CDs membranes show relatively good mechanical properties, based on stress resistance and flexibility to facilitate handling. The equilibrium state was reached within 5 min. Intriguingly, the UV-light illuminations enhanced the Cd2+ removal efficiency of the photoluminescent CDs substantially by four times faster under. It was found that adsorption followed pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity at 25 °C was found to be 112.4 mg g−1 at pH 8. This work paves the way to new applications of CDs in water treatment.Other Information Published in: Environmental Sciences Europe
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1186/s12302-020-0292-z
Resonant plasmon-phonon coupling and its role in magneto-thermoelectricity in bismuth
Creators: name: Chudzinski, P.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using diagrammatic methods we derive an effective interaction between a low energy collective movement of fermionic liquid (acoustic plasmon) and acoustic phonon. We show that the coupling between the plasmon and the lattice has a very non-trivial, resonant structure. When real and imaginary parts of the acoustic plasmon's velocity are of the same order as the phonon's velocity, the resonance qualitatively changes the nature of phonon-drag. In the following we study how magneto-thermoelectric properties are affected. Our result suggests that the novel mechanism of energy transfer between electron liquid and crystal lattice can be behind the huge Nernst effect in bismuth.
description: accepted in EPJB, to appear with a highlight
Resilience analytics: coverage and robustness in multi-modal transportation networks
Creators: name: Baggag, Abdelkader
name: Abbar, Sofiane
name: Zanouda, Tahar
name: Srivastava, Jaideep
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Applied computing
Numerical and computational mathematics

description: A multi-modal transportation system of a city can be modeled as a multiplex network with different layers corresponding to different transportation modes. These layers include, but are not limited to, bus network, metro network, and road network. Formally, a multiplex network is a multilayer graph in which the same set of nodes are connected by different types of relationships. Intra-layer relationships denote the road segments connecting stations of the same transportation mode, whereas inter-layer relationships represent connections between different transportation modes within the same station. Given a multi-modal transportation system of a city, we are interested in assessing its quality or efficiency by estimating the coverage i.e., a portion of the city that can be covered by a random walker who navigates through it within a given time budget, or steps. We are also interested in the robustness of the whole transportation system which denotes the degree to which the system is able to withstand a random or targeted failure affecting one or more parts of it. Previous approaches proposed a mathematical framework to numerically compute the coverage in multiplex networks. However solutions are usually based on eigenvalue decomposition, known to be time consuming and hard to obtain in the case of large systems. In this work, we propose MUME, an efficient algorithm for Multi-modal Urban Mobility Estimation, that takes advantage of the special structure of the supra-Laplacian matrix of the transportation multiplex, to compute the coverage of the system. We conduct a comprehensive series of experiments to demonstrate the effectiveness and efficiency of MUME on both synthetic and real transportation networks of various cities such as Paris, London, New York and Chicago. A future goal is to use this experience to make projections for a fast growing city like Doha.Other Information Published in: EPJ Data Science
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1140/epjds/s13688-018-0139-7
Deriving Universal Exponential Decay Dynamics from Quantum Interactions with the Cosmic Hilbert Space
Creators: name: Brown, Benjamin Reed
name: Anthropic AI Assistant
Publisher: name: Zenodo
Year: 2023
Subjects: Astrophysics
Physics
Quantum Mechanics

description: We present a technical derivation showing how subtle universal exponential decay processes inducing cosmic phenomena could emerge intrinsically from interactions between quantum states and the universal Hilbert space wave-function Ψ representing the total quantum state of the cosmos.
Black Silicon with Tunnel Oxide Passivated Contacts
Creators: name: Kloster, M.E.
name: Witthøft, M.-L.
name: Shearer, D.C.
name: Hajijafarassar, A.
name: Davidsen, R.S.
name: Petersen, D.H.
name: Hansen, O.
name: Iandolo, B.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Heterojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 668-671
description: We investigate surfaces of black silicon (bSi) fabricated by reactive ion etch (RIE) on n-type Si substrates and passivated by in-situ doped polycrystalline Si (poly-Si) deposited by low pressure chemical vapor deposition (LPCVD). We achieved full surface coverage of bSi surfaces for poly-Si thickness of 20 nm. We determined sheet resistance on p-type and n-type poly-Si by means of micro four-point probe measurements. Effective lifetime mapping on symmetrically passivated samples shows that n-type poly-Si offers excellent surface passivation after hydrogenation, reaching effective lifetime values of almost 4 ms on non-textured substrates. P-type poly-Si shows values of effective lifetime lower than 800 μs and requires further improvement. We calculated i-Voc of up to 711 mV and 609 mV for asymmetrically passivated lifetime samples without texturing and with bSi, respectively. The effective lifetime is limited by the less-than-optimal passivation of the p-type poly-Si. Preliminary solar cell measurements indicate that both cell voltage and fill factor require major improvement on textured surfaces. Current work is directed towards the following goals: improving the quality of the p-type poly-Si; testing possible replacement of wet chemistry to grow the tunnel oxide using dry furnace oxidation; fabricating and comparing cells with p-n junction at the front or at the bottom of the cell.
Stacks of a-SiOx:H/a-Si:H Passivation Layer for Low Parasitic Absorption and High Passivation in Silicon Heterojunction Solar Cells
Creators: name: Gotoh, K.
name: Cui, M.
name: Akaishi, R.
name: Kurokawa, Y.
name: Usami, N.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Heterojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 636-638
description: Silicon heterojunction (SHJ) solar cells employing hydrogenated amorphous Si (a-Si:H) have been intensively studied owing to the extremely high conversion efficiency, since remarkable suppression of carrier recombination is achieved. For further improvement of SHJ solar cells, parasitic absorption should be minimized. A promising candidate is hydrogenated amorphous silicon oxide (a-SiOx:H), which shows higher bandgap in comparison with that of a-Si:H. Although low parasitic absorption is realized by employing a-SiOx:H, passivation performance is sacrificed in some case. Recently, stacking of a-SiOx:H and a-Si:H have been proposed to achieve low parasitic absorption and surface recombination velocity. In this paper, we studied on optical and structural properties of a-SiOx:H single layer and implied VOC of a-SiOx:H/a-Si:H stacking layer on c-Si. With increasing gas flow ratio fCO2 = [CO2]/([SiH4] + [CO2]), optical bandgap monotonically increased. From Fourier transform infrared (FT-IR) spectroscopy, Si-O-Si stretching mode at around 980 cm-1 was observed for a-SiOx:H, indicating oxygen atoms are successfully incorporated in a-Si:H network. The implied VOC decreased with increase in fCO2 regardless of a-SiOx:H/a-Si:H stacking and a-SiOx:H single passivation layer. The higher implied VOC of a-SiOx:H/a-Si:H stacking layer are obtained in low fCO2 and thicker a-Si:H layer of the stacks possibly due to low defect density at the a-Si:H/c-Si interface in a-SiOx:H/a-Si:H stacking layer.
Comparison between Amorphous Silicon Layers Deposited for Heterojunction Solar Cells at 13.56 MHz and 140 MHz Excitation Frequency
Creators: name: Leszczynska, B.
name: Strobel, C.
name: Leszczynski, S.
name: Albert, M.
name: Stahr, F.
name: Kuske, J.
name: Bartha, J.W.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Heterojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 665-667
description: The plasma enhanced chemical vapor deposition (PECVD) process is used for the deposition of thin-film silicon. By varying the deposition conditions, it is possible to produce silicon layers with different material structures. The increase of the excitation frequency leads to a decrease of the ion bombardment energy on the growing layer and a reduction of the surface damage during the deposition is possible [1]. The recombination losses at the interface between absorber and emitter layer strongly affects the heterojunction solar cells (HIT) and excellent interfacial passivation is required [2]. For this purpose, the application of very high plasma excitation frequencies (VHF) for the deposition of passivation layers in comparison with standard radio frequency (RF) is investigated. The VHF-process enables a highly productive deposition of a-Si:H with a significant enhancement of the deposition rate. Thus, the influence of the deposition rate on layer properties for 13.56 and 140 MHz frequency will be presented.
Factors affecting cattle herd size among smallholder farmers in Timor-Leste
Creators: name: Antonio Vicente Daci Lelo, Pakapon Saiyut
Publisher: name: Faculty of Agriculture
Year: 2023
Subjects: Cattle farming system
cattle herd size
multiple regression analysis
smallholder cattle farmers
Timor-Leste

description: Khon Kaen Agriculture Journal, 51, 5, 1012-1027
Radiation forces and torque on a rigid elliptical cylinder in acoustical plane progressive and (quasi)standing waves with arbitrary incidence
Creators: name: Mitri, F. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: Analytical expressions for the axial and transverse acoustic radiation forces as well as the radiation torque per length are derived for a rigid elliptical cylinder placed arbitrarily in the field of in plane progressive, quasi-standing or standing waves. The rigid elliptical cylinder case is important to be considered as a first-order approximation of the behavior of a fluid particle suspended in air, because of the significant acoustic impedance mismatch at the particle's boundary. Based on the partial-wave series expansion method in cylindrical coordinates, non-dimensional acoustic radiation force and torque functions are derived and defined in terms of the scattering coefficients of the elliptic cylinder. A coupled system of linear equations is obtained after applying the Neumann boundary condition for an immovable surface in a non-viscous fluid, and solved numerically by matrix inversion after performing a single numerical integration procedure. Computational results for the non-dimensional force components and torque, showing the transition from the progressive to the (equi-amplitude) standing wave behavior, are performed with particular emphasis on the aspect ratio a/b, where a and b are the semi-axes of the ellipse, the dimensionless size parameter, as well as the angle of incidence ranging from end-on to broadside incidence. The results show that the elliptical geometry has a direct influence on the radiation force and torque, so that the standard theory for circular cylinders (at normal incidence) leads to significant miscalculations when the cylinder cross-section becomes non-circular. Moreover, the elliptical cylinder experiences, in addition to the acoustic radiation force, a radiation torque that vanishes for the circular cylinder case. The application of the formalism presented here may be extended to other 2D surfaces of arbitrary shape.
“God save us always from the innocent and the good”: American versus European Exceptionalism in Graham Greene’s The Quiet American
Creators: name: Griffin, Thomas Ross
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Political science
subject: FOS: Political science
subject: Historical studies

description: This essay argues that by challenging the rectitude of American intervention in Vietnam, The Quiet American is the means by which Greene criticises the American exceptionalism of the post-World War 2 era. It shows how the nation’s exceptionalism is built upon a fantasy of American idealism that masks the true intentions hidden behind America’s crusade against Communism. It proposes also that Greene uses his novel to highlight the existence of a European exceptionalism as potent as its transatlantic equivalent, and one much overlooked in contemporary discourse on Vietnam. The crux of Greene’s critique is located in Alden Pyle. Propped up by what Said describes as “structures of attitude and reference”, the article argues that Pyle’s rhetoric and actions demonstrate the blind commitment to American exceptionalism that Greene challenges in the text. The essay uses Donald Pease’s concept of the State of Exception to draw a parallel between the British journalist Thomas Fowler and Pyle to argue that in orchestrating the assassination of the latter, Fowler adopts the moral purpose that had prompted much of the American aid worker’s actions throughout the novel. It argues that this European version of exceptionalism comes from what Greene believed to be the suitability of European powers to oversee change in Vietnam, one that America was ill-equipped to handle. The essay ends by suggesting that The Quiet American was not so much what Diana Trilling described as “Mr Greene’s affront to America”, but an attempt to defend Europe amidst the onset of American dominance.Other Information Published in: Journal of Transatlantic Studies
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1057/s42738-021-00075-0
Understanding the buffering effect of social media use on anxiety during the COVID-19 pandemic lockdown
Creators: name: Marzouki, Yousri
name: Aldossari, Fatimah Salem
name: Veltri, Giuseppe A.
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Applied economics
Applied and developmental psychology

description: During the COVID-19 outbreak, lockdown measures have been deployed worldwide. In the wake of these measures, internet and social media use has reached unprecedented peaks. We hypothesize that social media can, in the context of the pandemic, be a placeholder for collective resilient processes modulated by cognitive and emotional components. An online survey (N = 1408) using a cross-sectional design was carried out over nine weeks from the beginning of March 2020 to the end of May 2020. The triangulation via SEM statistical modeling, text mining, and sentiment, discriminant, and entropy analyses revealed the granular functional role of social media use in promoting a positive perception towards stressors during the pandemic. This study provides an empirically tested theoretical framework to understand the evolution of buffering mechanisms of social media use as a result of collective resilience. Recommendations on social media use for future lockdown scenarios were provided.Other Information Published in: Humanities and Social Sciences Communications
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1057/s41599-021-00724-x
Gottesvorstellung, Ahnendienst und Dynamismus in der alten Tswana-Kultur
Creators: name: Häfner, Fritz A.
Publisher: name: Lutherische Beiträge
Year: 1970

description: Lutherische Beiträge, Bd. 7 Nr. 4 (2002): Lutherische Beiträge, Band 7, Heft 4
In-Situ Photoluminescence Study on Evolution of Passivation Properties during Plasma Exposure
Creators: name: Sreng, M.
name: Silva, F.
name: Roca I Cabarrocas, P.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 602-605
description: Vacuum UV light emitted from various plasma processes (e.g. deposition of amorphous silicon nitride by plasma-enhanced chemical vapor deposition (PECVD) or growth of transparent conductive oxides by sputtering) is known to cause a degradation of crystalline silicon surface passivation. A better understanding of the evolution of passivation properties under different plasma conditions is required to attenuate such detrimental effects. Using our in-house in-situ photoluminescence (PL) set-up, the passivation quality of crystalline silicon coated with aluminum oxide grown by atomic layer deposition or hydrogenated amorphous silicon grown by PECVD is characterized in real-time during argon-hydrogen plasma exposure. The PL signals emitted from both types of samples exhibit different behaviors at the very beginning of the treatment and also after turning off the plasma. These differences are linked with the passivation mechanism of both materials as well as the interaction between plasma emission and different types of chemical bonds at the interface. Furthermore, the relation between the passivation degradation induced by plasma and various plasma parameters (e.g. chamber pressure, RF power and substrate temperature) is also studied.
Unifying Matter Decay Phenomena from Quantum to Cosmic Scales
Creators: name: Brown, Benjamin Reed
name: Anthropic AI Assistant
Publisher: name: Zenodo
Year: 2023
Subjects: Astrophysics
Physics
Quantum Mechanics

description: This paper investigates potential mathematical links between unstable elementary particle decay processes described by widths Γ and analogous exponential cosmic mass-energy evaporation over eons theorized to induce accelerative expansion.
Evolution of Contact Formation on p-Type Crystalline Silicon Solar Cells
Creators: name: Mayberry, R.W.
name: Chandrasekaran, V.
name: Karpowich, L.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 617-620
description: This paper will examine the evolution of contact formation with temperature of a silver paste on a crystalline silicon solar cell. Detailed evaluation of the damage due to the front side grid metallization and its relation to contact formation and temperature will be carried out. Generally, a multi component silver paste is screen printed on a solar cell, then fired at high temperatures (750-800°C) to form an electrical contact to the base silicon material. The inorganic component, apart from silver (usually glass and/or crystalline additives), of the paste is responsible for reactions with the silicon nitride anti-reflective coating (ARC), silicon and silver that may lead to a low contact resistance between the metallization and bulk silicon. Knowledge of the detailed chemistry that controls the thermodynamic and kinetic temperature dependence of these reactions is generally vague and constantly changing. Both the formation and nature of silver crystallites, colloids, and precipitates formed at the silicon emitter region and in the glass layer will be investigated in detail over a wide range of temperatures. This will shed light on the evolution of contact formation with time and temperature for different metallization pastes.
Fully Ion-Implanted IBC Silicon Solar Cell with Gap Structure between Emitter and BSF by Self-Aligned Process
Creators: name: Tanahashi, K.
name: Tachibana, T.
name: Moriya, M.
name: Kida, Y.
name: Shirasawa, K.
name: Takato, H.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 624-627
description: We propose a fully implanted interdigitated back contact (IBC) silicon solar cell with a gap structure between the emitter and back surface field (BSF) fabricated using a self-aligned process with a single photolithography step. Boron was implanted on the entire rear side. After post-implantation annealing, the oxide layer was grown on the front and rear sides of the silicon wafer. The BSF region was patterned on the rear oxide layer via photolithography. A hollow structure with an overhang of the oxide layer was formed at the boundary between the emitter and BSF during the removal of the oxide and boron-implanted layer on the BSF region via reactive-ion etching and wet chemical etching. The overhanging oxide layer became the mask for subsequent phosphorus implantation on the BSF region.
Creation, Chaos, Time : from Myth to Modern Cosmology
Creators: name: Luminet, Jean-Pierre
Publisher: name: arXiv
Year: 2016
Subjects: subject: History and Philosophy of Physics (physics.hist-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Every society has a story rooted in its most ancient traditions, of how the earth and sky originated. Most of these stories attribute the origin of all things to a Creator - whether God, Element or Idea. We first recall that in the Western world all discussions of the origin of the world were dominated until the 18th century by the story of Genesis, which describes the Creation as an ordered process that took seven days. Then we show how the development of mechanistic theories in the 18th century meant that the idea of an organized Creation gave way to the concept of evolution, helped by the fact that in the 19th century astrophysicists discovered that stars had their origin in clouds of gas. We conclude with Big bang theory, conceived at the beginning of the 20th century, that was subsequently developed into a more or less complete account of the history of the cosmos, from the supposed birth of space, time and matter out of the quantum vacuum until the emergence of life (at least on our planet Earth, and much probably elsewhere) and beyond.
description: 15 pages, 0 figure
Potential of Chemical Rounding for the Performance Enhancement of a Pyramid-Textured Bifacial Si Bottom Cell
Creators: name: Lee, H.
name: Song, I.
name: Lee, S.W.
name: Bae, S.H.
name: Hyun, J.Y.
name: Kang, Y.
name: Lee, H.-S.
name: Ogura, A.
name: Kim, D.
name: Ohshita, Y.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 628-632
description: We have investigated the effects of chemical rounding on the performance of bifacial n-PERT silicon solar cells with a p+-emitter on a pyramid textured front surface. From the study, we found that solar weighted reflectance increases from ~2.5 to ~3.7% for AlOx/SiNx:H stack-passivated pyramid textured emitter samples according to chemical rounding time. Consequently, compared to the non-rounded cells, the Jsc of the 200-sec-rounded cells with ~60 and ~100 Ω/sq p+-emitters is reduced by 0.8 and 0.6 mA/cm2, respectively. However, the loss in Jsc is fully offset by the increased FF by 0.8 and 1.5% for the 200-sec-rounded cells with ~60 and ~100 Ω/sq p+-emitters, respectively. The efficiency of the 200-sec-rounded cells with a ~100 Ω/sq p+-emitter can be enhanced as a result, compared to the non-rounded cells. Finally, we investigated effects of chemical rounding on the optical property of an indium tin oxide layer widely used as a recombination layer for the fabrication of a monolithic perovskite/silicon tandem cell. From the results, it can be expected that efficiency of a bifacial n-PERT silicon bottom cell and its monolithic tandem cell with a perovskite top cell could be improved without additional complicated processes if chemical rounding and boron-doping processes can be properly optimized.
Emitter Formation and Passivation Dependence on Crystal Grain Orientations after Atmospheric Pressure Dry Nanotexturing
Creators: name: Ridoy, A.I.
name: Kafle, B.
name: Saint-Cast, P.
name: Lohmüller, S.
name: Norouzi, M.H.
name: Clochard, L.
name: Duffy, E.
name: Hofmann, M.
name: Rentsch, J.
name: Preu, R.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 606-609
description: In this work, we investigate the emitter performance of the multicrystalline silicon (mc-Si) solar cell as a function of the crystallographic orientation of the grains and the associated texturing level. Here, we applied a plasma-less nanotexturing process by atmospheric pressure dry etching that enables low reflectivity, followed by a short anisotropic alkaline etch. It is seen in our investigation that grains with lower reflection exhibit lower emitter sheet resistance (Rsh ≈ 72 Ω/sq.) than that of grains with higher reflection (Rsh ≈ 79 Ω/sq.). We show that with our current etching process flow, there is a linear correlation between charge carrier lifetime and weighted surface reflection of different grains in a mc-Si wafer.
Investigation on Post Cleanings on Modified Surface Using Laser Texturing
Creators: name: Radfar, B.
name: Es, F.
name: Turan, R.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 614-616
description: The surface of crystalline silicon (c-Si) solar cells can affect their performance as the surface can alter both electrical and optical properties. The c-Si texturing is carried out to increase the absorption; therefore, the optical properties will be enhanced. The anisotropic alkaline etchants are commonly used to form pyramids on the surface of monocrystalline Si wafers. However, this method is not usable for multi-crystalline silicon (mc-Si) because of its grains with random crystallographic orientations. The laser texturing, as an alternative method for texturing mc-Si wafers, is getting attention among texturing techniques. In this study, post-texture cleaning is investigated since it is a vital step after the laser texturing. This approach includes preparing the cleaning solution and performing the cleaning on the laser processed mc-Si wafers' surface. The different solution parameters, such as cleaning duration, temperature, and concentration, are justified by performing a series of experiments. To determine the effectiveness of the process, the weighted reflection and Scanning Electron Microscopy (SEM) images of the samples are considered. The SEM images show the evolution of the surface morphology versus cleaning duration, temperature, and concentration. Moreover, the measurements indicate that the samples’ weighted reflection can change dramatically by changing the cleaning solution parameters.
Number statistics for $β$-ensembles of random matrices: applications to trapped fermions at zero temperature
Creators: name: Marino, Ricardo
name: Majumdar, Satya N.
name: Schehr, Gregory
name: Vivo, Pierpaolo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Let $\mathcal{P}_β^{(V)} (N_{\cal I})$ be the probability that a $N\times N$ $β$-ensemble of random matrices with confining potential $V(x)$ has $N_{\cal I}$ eigenvalues inside an interval ${\cal I}=[a,b]$ of the real line. We introduce a general formalism, based on the Coulomb gas technique and the resolvent method, to compute analytically $\mathcal{P}_β^{(V)} (N_{\cal I})$ for large $N$. We show that this probability scales for large $N$ as $\mathcal{P}_β^{(V)} (N_{\cal I})\approx \exp\left(-βN^2 ψ^{(V)}(N_{\cal I} /N)\right)$, where $β$ is the Dyson index of the ensemble. The rate function $ψ^{(V)}(k_{\cal I})$, independent of $β$, is computed in terms of single integrals that can be easily evaluated numerically. The general formalism is then applied to the classical $β$-Gaussian (${\cal I}=[-L,L]$), $β$-Wishart (${\cal I}=[1,L]$) and $β$-Cauchy (${\cal I}=[-L,L]$) ensembles. Expanding the rate function around its minimum, we find that generically the number variance ${\rm Var}(N_{\cal I})$ exhibits a non-monotonic behavior as a function of the size of the interval, with a maximum that can be precisely characterized. These analytical results, corroborated by numerical simulations, provide the full counting statistics of many systems where random matrix models apply. In particular, we present results for the full counting statistics of zero temperature one-dimensional spinless fermions in a harmonic trap.
description: 34 pages, 19 figures
The Impact of Advanced Texturing on Saturation Current Density in n-Type PERT Silicon Solar Cell Processing
Creators: name: John, J.
name: Jambaldinni, S.
name: Haslinger, M.
name: Gocyla, M.
name: Hajjiah, A.
name: Kuzma-Filipek, I.
name: Tous, L.
name: Russell, R.
name: Duerinckx, F.
name: Szlufcik, J.
name: Poortmans, J.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 584-586
description: We report on the progress of wet chemical process development for silicon surface texturing of n-type
passivated emitter with rear totally diffused (n-PERT) solar cells. A KOH-based texturing process sequence has been
developed which provides potentially both improved conversion efficiency and reduction in cost of ownership (CoO). The
improvement in conversion efficiency is attributed to decreased saturation current density after diffusion and laser
processing, whereas, reduction of CoO is reached by reduced material consumption and process time. We have determined
the saturation current density after subsequent process steps like Boron emitter diffusion, Phosphorous back surface field
diffusion, passivation, laser ablation and selective laser doping for small pyramid (pyramid base length <2μm) and standard
texturing (pyramid base length 3-5μm), respectively.
Laser Doping from PSG for Selective FSF of Screen Printed Rear-Junction n-PERT Cells
Creators: name: Singh, S.
name: Tous, L.
name: Choulat, P.
name: Chen, J.
name: Liu, R.
name: Ma, L.
name: Wu, X.
name: Wang, J.
name: Liu, Z.
name: Duerinckx, F.
name: Gordon, I.
name: Szlufcik, J.
name: Poortmans, J.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Homojunction Solar Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 580-583
description: We report detailed studies on laser doping from phosphorus silicate glass (PSG) to form the selective
front surface field (FSF) for screen printed n-type passivated emitter, totally diffused (nPERT) solar cells. All relevant
parameters for the laser doping process have been characterized at different laser conditions. These include
measurements of sheet resistance, specific contact resistivity, recombination losses at the passivated laser-treated and
metallized surface (measured by J0n++pass and J0n++metal respectively), optical and scanning electron microscopy SEM
investigations. State of the art and very low dark saturation current densities have been achieved on passivated n+,
passivated laser doped (n++) and metalized surfaces while maintaining low specific contact resistivity. The developed
process for selective front surface field (FSF) with chosen doping parameters has been implemented in the monofacial
nPERT devices with screen printed contacts resulting in independently confirmed efficiencies up to 23%.
‘Writing’ small states: contextualizing the construct in the Arab Gulf
Creators: name: Sadiki, Larbi
name: Saleh, Layla
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Political science
subject: FOS: Political science

description: How do IR scholars ‘write’ the Arab Gulf? In attempting to address this question, the focus is twofold: first, the ‘small state’ as a construct and second, its application to the study of Gulf small states. The article tries to grapple with issues inherent in such an enterprise by providing a critical assessment of recent scholarship on the topic, with special reference to Qatar and the UAE. The problematic comes to the fore in a context of these two countries’ increasing regional and international visibility, as well as what seems to be renewed scholarly interest in small states, more generally. Specifically, this analysis primarily seeks to relativize the small state within the Arab Gulf sub-region, drawing attention to ontological and epistemological issues. In so doing, the article offers some heuristics for the writing of small states in the Arab Gulf. One suggestion put forward in the article is more scrutiny of the regional context; what is called here the ‘hydrocarbon semi-periphery’; and misgivings (conceptual and empirical) concerning, respectively, the treatment of ‘soft power,’ mediation, and intervention. One parting idea to derive from this line of inquiry is its cautionary note against inflating the utility or the explanatory power of a catch-all ‘small state’ construct when it comes to non-Western settings.Other Information Published in: International Politics
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1057/s41311-021-00335-y
A candidate optical counterpart to the middle-aged gamma-ray pulsar PSR J1741-2054
Creators: name: Mignani, R. P.
name: Testa, V.
name: Marelli, M.
name: De Luca, A.
name: Salvetti, D.
name: Belfiore, A.
name: Pierbattista, M.
name: Razzano, M.
name: Shearer, A.
name: Moran, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We carried out deep optical observations of the middle-aged $γ$-ray pulsar PSR J1741-2054 with the Very Large Telescope (VLT). We identified two objects, of magnitudes $m_v=23.10\pm0.05$ and $m_v=25.32\pm0.08$, at positions consistent with the very accurate Chandra coordinates of the pulsar, the faintest of which is more likely to be its counterpart. From the VLT images we also detected the known bow-shock nebula around PSR J1741-2054. The nebula is displaced by $\sim 0\farcs9$ (at the $3σ$ confidence level) with respect to its position measured in archival data, showing that the shock propagates in the interstellar medium consistently with the pulsar proper motion. Finally, we could not find evidence of large-scale extended optical emission associated with the pulsar wind nebula detected by Chandra, down to a surface brightness limit of $\sim 28.1$ magnitudes arcsec$^{-2}$. Future observations are needed to confirm the optical identification of PSR J1741-2054 and characterise the spectrum of its counterpart.
description: 8 pages, 3 figures, Astrophysical Journal, in press