cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Rights and Legislation for LGBTQ+ Persons: Regulata (Relationship regulations data)
Creators: name: Seitzer, Helen
Publisher: name: Universität Bremen
Year: 2022
Subjects: subject: family data
subject: LGBTQ+ data
subject: 300

description: This technical paper gives an overview of the new data set on family data with a focus on LGBTQ+ policies. It comprises rules and regulations to help researchers understand how this policy sector evolved throughout time. The data set contains indicators on adoption laws, constitutional and workplace anti-discrimination protection, civil contracts and marriage laws, the restriction of gender expression, and more. While there are activism groups and other community efforts to collect data, there are no comprehensive datasets available in this format. Therefore, this data set contains enactment dates of regulations regarding the LGBTQ+ community, which can be useful for event history modelling in an academic context.
The assessment of cadmium, chromium, copper, and nickel tolerance and bioaccumulation by shrub plant Tetraena qataranse
Creators: name: Usman, Kamal
name: Al-Ghouti, Mohammad A.
name: Abu-Dieyeh, Mohammed H.
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Environmental engineering
subject: FOS: Environmental engineering

description: Heavy metals constitute some of the most significant environmental contaminants today. The abundance of naturally growing Tetraena qataranse around Ras Laffan oil and gas facilities in the state of Qatar reflects its toxitolerant character. This study examined the desert plant’s tolerance to Ba, Cd, Cr, Cu, Ni and Pb relative to soil concentration. Analysis by inductively coupled plasma – optical emission spectroscopy (ICP-OES) showed that the plant biomass accumulates higher Cd, Cr, Cu and Ni concentration than the soil, particularly in the root. The bioconcentration factor (BCF) of all metals in the root and shoot indicates the plant’s capacity to accumulate these metals. Cd had a translocation factor (TF) greater than one; however, it is less than one for all other metals, suggesting that the plant remediate Cd by phytoextraction, where it accumulates in the shoot and Cr, Cu and Ni through phytostabilization, concentrating the metals in the root. Metals phytostabilization restrict transport, shield animals from toxic species ingestion, and consequently prevent transmission across the food chain. Fourier Transform Infrared Spectroscopy (FTIR) analysis further corroborates ICP-OES quantitative data. Our results suggest that T. qataranse is tolerant of Cd, Cr, Cu, and Ni. Potentially, these metals can accumulate at higher concentration than shown here; hence, T. qataranse is a suitable candidate for toxic metals phytostabilization.Other Information Published in: Scientific Reports
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-019-42029-9
DNAJB3 attenuates metabolic stress and promotes glucose uptake by eliciting Glut4 translocation
Creators: name: Arredouani, Abdelilah
name: Diane, Abdoulaye
name: Khattab, Namat
name: Bensmail, Ilham
name: Aoude, Imad
name: Chikri, Mohamed
name: Mohammad, Ramzi
name: Abou-Samra, Abdul Badi
name: Dehbi, Mohammed
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Medical biochemistry and metabolomics

description: Failure of the heat shock response is a key event that leads to insulin resistance and type 2 diabetes. We recently showed that DNAJB3 co-chaperone is downregulated in obese and diabetic patients and that physical exercise restores its normal expression with a significant improvement of the clinical outcomes. In 3T3-L1 adipocytes, DNAJB3 has a role in improving the sensitivity to insulin and glucose uptake. In co-immunoprecipitation assays, DNAJB3 interacts with both JNK1 and IKKβ kinases. However, the functional impact of such interaction on their activities has not been investigated. Here, we assessed the effect of DNAJB3 on the respective activity of JNK1 and IKKβ in cell-based assays. Using JNK1- and IKKβ-dependent luciferase reporters, we show a marked decrease in luciferase activity by DNAJB3 in response to PMA and TNF-α that was consistent with a decrease in the translocation of p65/NF-κB to the nucleus in response to LPS. Furthermore, TNF-α-mediated IL-6 promoter activation and endogenous mRNA expression are significantly abrogated by DNAJB3 both in 3T3-L1 and C2C12 cells. The ability of DNAJB3 to mitigate ER stress and oxidative stress was also investigated and our data show a significant improvement of both forms of stress. Finally, we examined the effect of overexpressing and knocking down the expression of DNAJB3 on glucose uptake in C2C12 as well as the molecular determinants. Accordingly, we provide evidence for a role of DNAJB3 in promoting both basal and insulin-stimulated glucose uptake. Our finding reveals also a novel role of DNAJB3 in eliciting Glut4 translocation to the plasma membrane. These results suggest a physiological role of DNAJB3 in mitigating metabolic stress and improving glucose homeostasis and could therefore represent a novel therapeutic target for type 2 diabetes.Other Information Published in: Scientific Reports
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-019-41244-8
Adsorption of phosphate on iron oxide doped halloysite nanotubes
Creators: name: Almasri, Dema A.
name: Saleh, Navid B.
name: Atieh, Muataz A.
name: McKay, Gordon
name: Ahzi, Said
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Nanotechnology
subject: FOS: Nanotechnology

description: Excess phosphate in water is known to cause eutrophication, and its removal is imperative. Nanoclay minerals are widely used in environmental remediation due to their low-cost, adequate availability, environmental compatibility, and adsorption efficiency. However, the removal of anions with nanoclays is not very effective because of electrostatic repulsion from clay surfaces with a net negative charge. Among clay minerals, halloysite nanotubes (HNTs) possess a negatively charged exterior and a positively charged inner lumen. This provides an increased affinity for anion removal. In this study, HNTs are modified with nano-scale iron oxide (Fe2O3) to enhance the adsorption capacity of the nanosorbent. This modification allowed for effective distribution of these oxide surfaces, which are known to sorb phosphate via ligand exchange and by forming inner-sphere complexes. A detailed characterization of the raw and (Fe2O3) modified HNTs (Fe-HNT) is conducted. Influences of Fe2O3 loading, adsorbent dosage, contact time, pH, initial phosphate concentration, and coexisting ions on the phosphate adsorption capacity are studied. Results demonstrate that adsorption on Fe-HNT is pH-dependent with fast initial adsorption kinetics. The underlying mechanism is identified as a combination of electrostatic attraction, ligand exchange, and Lewis acid-base interactions. The nanomaterial provides promising results for its application in water/wastewater treatment.Other Information Published in: Scientific Reports
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-019-39035-2
Introducing RED – The Relational Export Dataset
Creators: name: Lischka, Michael
name: Besche-Truthe, Fabian
Publisher: name: Universität Bremen
Year: 2022
Subjects: subject: trade data
subject: trade linkages
subject: 300

description: This technical paper gives an overview of our new data set on trade data (RED). It provides comparable dyadic trade data between nation-states for the period 1870 to 2018. To do this, it follows an interdependence-centred approach to explain the diffusion of governmental social policies. We deliver temporally consistent data on interstate linkages for the largest possible sample of countries by combining trade data from UN Comtrade (Comtrade, 2022), UNCTAD (UNCTAD, 2021), and the Correlates of War (COW) Project. In contrast to other data sets, the RED does not represent absolute monetary trade volumes in a given currency. Rather it depicts the ratio of trade flows between two countries and the total exports of the specific exporting country. So far there has been no data set that meets these requirements. As we show during this paper, the use of RED helps finding more detailed results.
Diedrich, Hans-Christian; Sticker, Gerd; Tchoerner, Helmut (Hg.): Das Gute behaltet
Creators: name: Junker, Johannes
Publisher: name: Lutherische Beiträge
Year: 1970

description: Lutherische Beiträge, Bd. 7 Nr. 1 (2002): Lutherische Beiträge, Band 7, Heft 1
Die Region Bremen
Creators: name: Nischwitz, Guido
name: Von Bestenbostel, Martin
name: Knieling, Fiona
name: Schwarz, Maren
Publisher: name: Arbeitnehmerkammer Bremen
Year: 2023
Subjects: subject: Analyse
subject: regionale Verflechtung
subject: Bremen (Stadt)
subject: Wirtschaftsförderung
subject: Gesundheitsförderung
subject: Wohnungssituation
subject: Mobilität
subject: 360

description: Herausforderungen der regionalen Verflechtungen der Stadt Bremen mit ihrem niedersächsischen Umland. Die vorliegende Studie des iaw konzentriert sich auf eine Analyse von vier in der Region Bremen bedeutsamen Handlungsfeldern: Wirtschaftsföderung und Gewerbeflächen, Wohnungsmarkt, Mobilität und Verkehrsowie Gesundheitsförderung.
Influence of Low-Temperature Annealing before Firing on LeTID in Multicrystalline Silicon
Creators: name: Schmid, A.
name: Lindroos, J.
name: Zuschlag, A.
name: Skorka, D.
name: Fritz, J.
name: Hahn, G.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Feedstock, Crystallisation, Wafering, Defect Engineering

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 342-345
description: Light and elevated temperature induced degradation (LeTID) affects significantly the performance of
multicrystalline silicon (mc-Si) solar cells. Even though the underlying mechanisms of LeTID and subsequent
regeneration are still unknown, LeTID formation is known to be influenced by surface passivation, firing, and lowtemperature
annealing after firing. Since both the firing peak temperature and the cooling profile strongly influence
LeTID, firing is presumed to dominate over any preceding low-temperature steps. However, lifetime measurements
during illumination (1.0 ±0.1 suns) at 150°C show a clear difference in the LeTID defect density in samples annealed
at 200-500°C before aluminum oxide deposition and before firing. Additionally, LeTID becomes worse when the prefiring
annealing is performed in an H plasma atmosphere. Therefore, the firing step does not erase the impact of lowtemperature
annealing or pre-firing hydrogenation on LeTID. Finally, thinner samples are shown to cause lower initial
effective lifetimes (eff) and less LeTID.
Figuring Out Art History
Creators: name: Schich, Maximilian
Publisher: name: arXiv
Year: 2015
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Biological sciences
subject: J.5; J.4; J.2; E.1
subject: 91D10 (Primary), 94C15, 68R10 (Secondary)

description: World population and the number of cultural artifacts are growing exponentially or faster, while cultural interaction approaches the fidelity of a global nervous system. Every day hundreds of millions of images are loaded into social networks by users all over the world. As this myriad of new artifacts veils the view into the past, like city lights covering the night sky, it is easy to forget that there is more than one Starry Night, the painting by Van Gogh. Like in ecology, where saving rare species may help us in treating disease, art and architectural history can reveal insights into the past, which may hold keys to our own future. With humanism under threat, facing the challenge of understanding the structure and dynamics of art and culture, both qualitatively and quantitatively, is more crucial now than it ever was. The purpose of this article is to provide perspective in the aim of figuring out the process of art history - not art history as a discipline, but the actual history of all made things, in the spirit of George Kubler and Marcel Duchamp. In other words, this article deals with the grand challenge of developing a systematic science of art and culture, no matter what, and no matter how.
description: 22 pages, 5 figures
Automatic Feature Fairness in Recommendation via Adversaries
Creators: name: Hu, Hengchang
name: Cao, Yiming
name: He, Zhankui
name: Tan, Samson
name: Kan, Min-Yen
Publisher: name: arXiv
Year: 2023
Subjects: subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Fairness is a widely discussed topic in recommender systems, but its practical implementation faces challenges in defining sensitive features while maintaining recommendation accuracy. We propose feature fairness as the foundation to achieve equitable treatment across diverse groups defined by various feature combinations. This improves overall accuracy through balanced feature generalizability. We introduce unbiased feature learning through adversarial training, using adversarial perturbation to enhance feature representation. The adversaries improve model generalization for under-represented features. We adapt adversaries automatically based on two forms of feature biases: frequency and combination variety of feature values. This allows us to dynamically adjust perturbation strengths and adversarial training weights. Stronger perturbations are applied to feature values with fewer combination varieties to improve generalization, while higher weights for low-frequency features address training imbalances. We leverage the Adaptive Adversarial perturbation based on the widely-applied Factorization Machine (AAFM) as our backbone model. In experiments, AAFM surpasses strong baselines in both fairness and accuracy measures. AAFM excels in providing item- and user-fairness for single- and multi-feature tasks, showcasing their versatility and scalability. To maintain good accuracy, we find that adversarial perturbation must be well-managed: during training, perturbations should not overly persist and their strengths should decay.
description: SIGIR-AP'23
Improved Contactless Method of IR Reflectance under Grazing Incidence for Measurement of Doping Profiles
Creators: name: Holovsky, J.
name: Remes, Z.
name: Franta, D.
name: Conrad, B.
name: Abelová, L.
name: Bušek, D.
name: Poruba, A.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Characterisation & Simulation Methods for Si Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 278-280
description: We have elaborated contactless method of measurement and evaluation of doping profiles in silicon
polished wafers based on infrared reflectance under high angle of incidence. We have found higher angle of incidence
increases sensitivity, however approaching Brewster angle increases also experimental error, therefore 65 angle has
been chosen. Moreover, to increase reproducibility we divide the measured spectra by reference spectra taken on an
undoped sample, and further we rescale the spectra to fixed value in the region of 4000 cm-1–7000 cm-1. To reduce
number of evaluated parameter, the carrier profile in boron-doped samples was parametrized by 3 parameters and that
in phosphorous-doped samples was parametrized by 4 parameters, using additional empirically determined assumption
that the first part of the profile is a constant plateau and that the following two exponential tails are joined at a value of
3x1019 cm-3. As a physical model, the classical Drude equation is used and revised, leading to adjustment of effective
mass and assuming concentration-dependent relaxation time and the contribution from band-to-band excitations. The
relation of concentration-dependent relaxation time was represented in the range of interest by a power law that
significantly deviates from typically used empirical data. The reason is that the empirical data had been obtained as a
function of dopant density and not free carrier density. Because the doping efficiency drops at higher concentration this
empirical data could not be used. This is one of the most important advancement of the free carrier absorption model.
Finally, the model parameters were calibrated independently by infrared ellipsometry. Satisfactory agreement with the
profiles measured by the electrochemical capacitance-voltage method was reached. The measurement using Fouriertransform
infrared spectrophotometer takes few seconds and can be implemented as an in-line characterization
technique in industry.
European VLBI Network imaging of 6.7 GHz methanol masers
Creators: name: Bartkiewicz, Anna
name: Szymczak, Marian
name: van Langevelde, Huib J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Methanol masers at 6.7 GHz are well known tracers of high-mass star-forming regions. However, their origin is still not clearly understood. We aimed to determine the morphology and velocity structure for a large sample of the maser emission with generally lower peak flux densities than those in previous surveys. Using the European VLBI Network we imaged the remaining sources (17) from a sample of sources that were selected from the unbiased survey using the Torun 32 m dish. Together they form a database of a total of 63 source images with high sensitivity, milliarcsecond angular resolution and very good spectral resolution for detailed studies. We studied in detail the properties of the maser clouds and calculated the mean and median values of the projected size (17.4 au and 5.5 au, respectively) as well as the FWHM of the line (0.373 km s$^{-1}$ and 0.315 km s$^{-1}$ for the mean and median values, respectively), testing whether it was consistent with Gaussian profile. We also found maser clouds with velocity gradients (71 per cent) that ranged from 0.005 km s$^{-1}$ au$^{-1}$ to 0.210 km s$^{-1}$ au$^{-1}$. We tested the kinematic models to explain the observed structures of the 6.7 GHz emission. There were targets where the morphology supported the scenario of a rotating and expanding disk or a bipolar outflow. Comparing the interferometric and single-dish spectra we found that, typically, 50-70 per cent of the flux was missing. This phenomena is not strongly related to the distance of the source. The EVN imaging reveals that in the complete sample of 63 sources the ring-like morphology appeared in 17 per cent of sources, arcs were seen in a further 8 per cent, and the structures were complex in 46 per cent cases. The UC HII regions coincide in position in the sky for 13 per cent of the sources. They are related both to extremely high and low luminosity masers from the sample.
description: Accepted for publication in Astronomy and Astrophysics
Evaluation of cationic channel TRPV2 as a novel biomarker and therapeutic target in Leukemia-Implications concerning the resolution of pulmonary inflammation
Creators: name: Siveen, Kodappully S.
name: Prabhu, Kirti S.
name: Parray, Aeijaz S.
name: Merhi, Maysaloun
name: Arredouani, Abdelilah
name: Chikri, Mohamed
name: Uddin, Shahab
name: Dermime, Said
name: Mohammad, Ramzi M.
name: Steinhoff, Martin
name: Janahi, Ibrahim A.
name: Azizi, Fouad
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: Clinical sciences

description: Patients treated during leukemia face the risk of complications including pulmonary dysfunction that may result from infiltration of leukemic blast cells (LBCs) into lung parenchyma and interstitium. In LBCs, we demonstrated that transient receptor potential vanilloid type 2 channel (TRPV2), reputed for its role in inflammatory processes, exhibited oncogenic activity associated with alteration of its molecular expression profile. TRPV2 was overexpressed in LBCs compared to normal human peripheral blood mononuclear cells (PBMCs). Additionally, functional full length isoform and nonfunctional short form pore-less variant of TRPV2 protein were up-regulated and down-regulated respectively in LBCs. However, the opposite was found in PBMCs. TRPV2 silencing or pharmacological targeting by Tranilast (TL) or SKF96365 (SKF) triggered caspace-mediated apoptosis and cell cycle arrest. TL and SKF inhibited chemotactic peptide fMLP-induced response linked to TRPV2 Ca2+ activity, and down-regulated expression of surface marker CD38 involved in leukemia and lung airway inflammation. Challenging lung airway epithelial cells (AECs) with LBCs decreased (by more than 50%) transepithelial resistance (TER) denoting barrier function alteration. Importantly, TL prevented such loss in TER. Therefore, TRPV2 merits further exploration as a pharmacodynamic biomarker for leukemia patients (with pulmonary inflammation) who might be suitable for a novel [adjuvant] therapeutic strategy based on TL.Other Information Published in: Scientific Reports
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-018-37469-8
A Study of Children’s STEM Learning in the Chinese Kindergarten Context: Conceptual PlayWorld as a New Play Practice
Creators: name: MA, YUWEN
Publisher: name: Monash University
Year: 2023
Subjects: classificationCode: 390302
subject: Early childhood education

description: Drawing from cultural-historical theory, this study explored how a Conceptual PlayWorld created conditions for children's STEM learning in the Chinese kindergarten context. As a part of the educational experiment, the Conceptual PlayWorld was implemented in two classrooms with 4 to 5- year-old children for seven months. Digital video observation and interviews were used to collect data. Applying Hedegaard's three levels of interpretation, findings revealed that the Conceptual PlayWorld created a new social situation for Chinese children through collective imaginary situations, dramatic problems, play narratives and dynamic interactions. This new play practice promoted Chinese children’s agency, meaningful learning and theoretical thinking in STEM.
Historical Education System Data (HESDat)
Creators: name: Windzio, Michael
name: Besche-Truthe, Fabian
name: Seitzer, Helen
Publisher: name: Universität Bremen
Year: 2021
Subjects: subject: education data
subject: education systems
subject: policy diffusion
subject: 300

description: This technical paper gives an overview of the new data set on education (systems). The historical education system dataset (HESDat) was collected to facilitate a comprehensive description and explanation of the dynamics of emergence, diffusion, and transformation in state education systems. It allows the investigation of the causes of change and reform from a global and historical perspective. HESDat currently contains 63 different indicators on education systems, from state-mandated reforms to policy practice and system performance with a focus on compulsory structures. So far, we collected data for 170 states from the years 1739 to 2020. The extensive historical reach, as well as the inclusion of historical political entities to trace the diffusion of education policy, is a unique perspective that allows the assessment of policy diffusion to an unprecedented extent.
Broadband observations of the X-ray burster 4U 1705-44 with BeppoSAX
Creators: name: Piraino, S.
name: Santangelo, A.
name: Mueck, B.
name: Kaaret, P.
name: Di Salvo, T.
name: D'Ai, A.
name: Iaria, R.
name: Egron, E.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: 4U 1705-44 is one of the most-studied type I X-ray burster and Atoll sources. This source represents a perfect candidate to test different models proposed to self-consistently track the physical changes occurring between different spectral states because it shows clear spectral state transitions. The broadband coverage, the sensitivity and energy resolution of the BeppoSAX satellite offers the opportunity to disentangle the components that form the total X-ray spectrum and to study their changes according to the spectral state. Using two BeppoSAX observations carried out in August and October 2000, respectively, for a total effective exposure time of about 100 ks, we study the spectral evolution of the source from a soft to hard state. Energy spectra are selected according to the source position in the color-color diagram (CCD) Results. We succeeded in modeling the spectra of the source using a physical self-consistent scenario for both the island and banana branches (the double Comptonization scenario). The components observed are the soft Comptonization and hard Comptonization, the blackbody, and a reflection component with a broad iron line. When the source moves from the banana state to the island state, the parameters of the two Comptonization components change significantly and the blackbody component becomes too weak to be detected. We interpret the soft Comptonization component as emission from the hot plasma surrounding the neutron star, hard Comptonization as emission from the disk region, and the blackbody component as emission from the inner accretion disk. The broad feature in the iron line region is compatible with reflection from the inner accretion disk.
description: 8 pages, 10 figures, accepted for publication by A&A
Anti-corrosive and oil sensitive coatings based on epoxy/polyaniline/magnetite-clay composites through diazonium interfacial chemistry
Creators: name: Jlassi, Khouloud
name: Radwan, A. Bahgat
name: Sadasivuni, Kishor Kumar
name: Mrlik, Miroslav
name: Abdullah, Aboubakr M.
name: Chehimi, Mohamed M.
name: Krupa, Igor
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Materials engineering
subject: FOS: Materials engineering

description: Epoxy polymer nanocomposites filled with magnetite (Fe3O4) clay (B), named (B-DPA-PANI@Fe3O4) have been prepared at different filler loading (0.1, 0.5, 1, 3, 5 wt. %). The surface modification of clay by polyaniline (PANI) is achieved in the presence of 4-diphenylamine diazonium salt (DPA). The effects of the nanofiller loading on Tensile, mechanical and dielectric properties were systematically studied. Improved properties was highlighted for all reinforced samples. The addition of only 3 wt. % of the filler enhanced the tensile strength of the composites by 256%, and the glass transition temperature Tg by 37%. The dielectric spectra over a broad frequency showed a robust interface between the hybrid (B-DPA-PANI@Fe3O4) fillers and epoxy matrix. The results showed most significant improvement in corrosion inhibition using electrochemical impedance spectroscopy (EIS) in 3.5 wt % NaCl, as well as a significant response in oil sensing test. High charge transfer resistance of 110 × 106 Ω.cm2 using 3-wt % of filler was noted compared to 0.35 × 106 Ω.cm2 for the pure epoxy. The results obtained herein will open new routes for the preparation of efficient anticorrosion sensor coatings.Other Information Published in: Scientific Reports
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-018-31508-0
Influence of Emitter Layers on LeTID Kinetics in Multicrystalline Silicon
Creators: name: Otaegi, A.
name: Skorka, D.
name: Schmid, A.
name: Zuschlag, A.
name: Jimeno, J.C.
name: Hahn, G.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Characterisation & Simulation Methods for Si Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 293-297
description: The influence of emitter layers on LeTID kinetics in multicrystalline silicon is analysed in this work. Multicrystalline silicon samples with emitter layers with sheet resistivity of 60, 175, 200, 230 and 360 Ω/sq have been processed and exposed afterwards to 1 sun illumination at 75ºC for more than 2000 h. The effective lifetime of the minority charge carriers of the samples has been measured repetitively by spatially resolved photoluminescence. The resulting lifetime maps are analysed and the effective defect concentration of the samples is calculated. This approach leads to different degradation rates, depending on the emitter sheet resistivity, and to the same defect regeneration rate, but differing in the onset of regeneration.
Conformal Gauge-Yukawa Theories away From Four Dimensions
Creators: name: Codello, Alessandro
name: Langaeble, Kasper
name: Litim, Daniel
name: Sannino, Francesco
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the phase diagram and associated fixed points for a wide class of Gauge-Yukawa theories in $d=4+ε$ dimensions. The theories we investigate involve non-abelian gauge fields, fermions and scalars in the Veneziano-Witten limit. The analysis is performed in steps, we start with QCD$_d$ and then we add Yukawa interactions and scalars which we study at next-to- and next-to-next-to-leading order. Interacting infrared fixed points naturally emerge in dimensions lower than four while ultraviolet ones appear above four. We also analyse the stability of the scalar potential for the discovered fixed points. We argue for a very rich phase diagram in three dimensions while in dimensions higher than four certain Gauge-Yukawa theories are ultraviolet complete because of the emergence of an asymptotically safe fixed point.
description: RevTeX, 2columns, 9 pages, 6 figures
Influence of Household Water Filters on Bacteria Growth and Trace Metals in Tap Water of Doha, Qatar
Creators: name: Nriagu, Jerome
name: Xi, Chuanwu
name: Siddique, Azhar
name: Vincent, Annette
name: Shomar, Basem
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Public health

description: Deteriorating water quality from aging infrastructure, growing threat of pollution from industrialization and urbanization, and increasing awareness about waterborne diseases are among the factors driving the surge in worldwide use of point-of-entry (POE) and point-of-use (POU) filters. Any adverse influence of such consumer point-of-use systems on quality of water at the tap remains poorly understood, however. We determined the chemical and microbiological changes in municipal water from the point of entry into the household plumbing system until it leaves from the tap in houses equipped with filters. We show that POE/POU devices can induce significant deterioration of the quality of tap water by functioning as traps and reservoirs for sludge, scale, rust, algae or slime deposits which promote microbial growth and biofilm formation in the household water distribution system. With changes in water pressure and physical or chemical disturbance of the plumbing system, the microorganisms and contaminants may be flushed into the tap water. Such changes in quality of household water carry a potential health risk which calls for some introspection in widespread deployment of POE/POU filters in water distribution systems.Other Information Published in: Scientific Reports
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-018-26529-8
Internal energy of the classical two- and three-dimensional one-component-plasma
Creators: name: Khrapak, S. A.
name: Khrapak, A. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: We summarize several semi-phenomenological approaches to estimate the internal energy of one-component-plasma (OCP) in two (2D) and three (3D) dimensions. Particular attention is given to a hybrid approach, which reproduces the Debye-H$\ddot{\text{u}}$ckel asymptote in the limit of weak coupling, the ion sphere (3D) and ion disc (2D) asymptotes in the limit of strong coupling, and provides reasonable interpolation between these two limits. More accurate ways to estimate the internal energy of 2D and 3D OCP are also discussed. The accuracy of these analytic results is quantified by comparison with existing data from numerical simulations. The relevance of the KTHNY theory in locating melting transition in 2D OCP is briefly discussed.
description: to be published in Contributions to Plasma Physics (2016)
A Novel Architecture for Carbon Nanotube Membranes towards Fast and Efficient Oil/water Separation
Creators: name: Saththasivam, Jayaprakash
name: Yiming, Wubulikasimu
name: Wang, Kui
name: Jin, Jian
name: Liu, Zhaoyang
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Materials engineering
subject: FOS: Materials engineering
subject: Nanotechnology
subject: FOS: Nanotechnology

description: Carbon nanotubes (CNT) are robust and proven as promising building blocks for oil/water separating membranes. However, according to classic fluid dynamic theory, achieving high permeation flux without sacrificing other membrane properties is a formidable challenge for CNT membranes, because of the trade-off nature among key membrane parameters. Herein, to relieve the trade-off between permeation fluxes, oil rejection rate, and membrane thickness, we present a new concept to engineer CNT membranes with a three-dimensional (3D) architecture. Apart from achieving high oil separation efficiency (>99.9%), these new oil/water separating membranes can achieve water flux as high as 5,500 L/m2.h.bar, which is one order of magnitude higher than pristine CNT membranes. Most importantly, these outstanding properties can be achieved without drastically slashing membrane thickness down to nanoscale. The present study sheds a new light for the adoption of CNT-based membranes in oil/water separation industry.Other Information Published in: Scientific Reports
 License: https://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-018-25788-9
Challenges for the Quantification of Metal Induced Recombination Losses
Creators: name: Herrmann, D.
name: Lohmüller, S.
name: Höffler, H.
name: Fell, A.
name: Brand, A.A.
name: Wolf, A.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Characterisation & Simulation Methods for Si Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 287-292
description: One major loss mechanism for the currently highly relevant passivated emitter and rear cells (PERC) is
locally enhanced recombination at the interface between semiconductor and front side metallization. For investigating
these losses in detail, a reliable detection technique is crucial. A method we call calibrated photoluminescence
imaging (PLI) method is a promising technique to extract the local dark saturation current density in the metallized
area j0,loc. To investigate the sources of error of this method, metallized test samples are processed and the influence
of sample specific parameters is considered in detail. Additionally, the difference in the resulting j0,loc between the
calibrated PLI method and a simulative approach using numerical PLI simulations (Quokka3) is evaluated. We find
that the results from the calibrated PLI method strongly depend on the accurate knowledge of the base resistivity B
(including the impact of thermal donors) and less strongly on the reflectivity R of the illuminated side of the sample.
In addition, metastable defects in the Si bulk can falsify the results, due to changes in the PLI intensity as a function
of the illumination time. The difference in the resulting j0,loc between the calibrated PLI method and the simulative
approach is within the error tolerances, which implies that the calibrated PLI method delivers accurate results despite
the assumption of a uniform n throughout the sample. Here, it is important to mention that the non-uniformity of n
is expected to be stronger for structures without a highly doped region at the investigated side (e.g. PERC rear
contacts).
Subsubleading soft theorems of gravitons and dilatons in the bosonic string
Creators: name: Di Vecchia, Paolo
name: Marotta, Raffaele
name: Mojaza, Matin
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Starting from the amplitude with an arbitrary number of massless closed states of the bosonic string, we compute the soft limit when one of the states becomes soft to subsubleading order in the soft momentum expansion, and we show that when the soft state is a graviton or a dilaton, the full string amplitude can be expressed as a soft theorem through subsubleading order. It turns out that there are string corrections to the field theoretical limit in the case of a soft graviton, while for a soft dilaton the string corrections vanish. We then show that the new soft theorems, including the string corrections, can be simply obtained from the exchange diagrams where the soft state is attached to the other external states through the three-point string vertex of three massless states. In the soft-limit, the propagator of the exchanged state is divergent, and at tree-level these are the only divergent contributions to the full amplitude. However, they do not form a gauge invariant subset and must be supplemented with extra non-singular terms. The requirement of gauge invariance then fixes the complete amplitude through subsubleading order in the soft expansion, reproducing exactly what one gets from the explicit calculation in string theory. From this it is seen that the string corrections at subsubleading order arise as a consequence of the three-point amplitude having string corrections in the bosonic string. When specialized to a soft dilaton, it remarkably turns out that the string corrections vanish and that the non-singular piece of the subsubleading term of the dilaton soft theorem is the generator of space-time special conformal transformation.
description: 34 pages, 2 figures, 2 appendices
Capacitive Effects in High-Efficiency Solar Cells during I-V Curve Measurement: Considerations on Error of Correction and Extraction of Minority Carrier Lifetime
Creators: name: Vahlman, H.
name: Lipping, J.
name: Hyvärinen, J.
name: Tolvanen, A.
name: Hyvärinen, S.
Publisher: name: WIP
Year: 2018
Subjects: Silicon Cells
Characterisation & Simulation Methods for Si Cells

description: 35th European Photovoltaic Solar Energy Conference and Exhibition; 254-261
description: High-efficiency solar cells have a high internal capacitance that tends to distort I-V measurements during
short voltage sweep times compatible with flash testing. Recently, it was shown that this distortion can be corrected
with a weighted average of the measured output currents, using time derivatives of junction voltage as weighting
factors. Although this procedure theoretically reproduces the steady-state I-V curve, errors from different sources exist.
For example, time derivatives of measurement data are potentially sensitive to even low levels of noise in the original
signal. In addition, the correction requires prior determination of the series resistance, which can be susceptible to an
error. In this contribution, we investigate errors associated with the capacitance correction. We estimate the magnitude
of additional noise that derives from using time derivatives of measurement data as weighting factors, as well as the
significance of an error in the series resistance. Further, we provide indications that the physical lower limit for the
voltage sweep length is dictated by minority carrier diffusivity. Additionally, we show that the effective minority carrier
lifetime of the solar cell can be estimated based on output currents and time derivatives of the junction voltage during
forward and reverse sweeps.
Josephson vortex loops in nanostructured Josephson junctions
Creators: name: Berdiyorov, G. R.
name: Milošević, M. V.
name: Kusmartsev, F.
name: Peeters, F. M.
name: Savel’ev, S.
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Materials engineering
subject: FOS: Materials engineering
subject: Nanotechnology
subject: FOS: Nanotechnology

description: Linked and knotted vortex loops have recently received a revival of interest. Such three-dimensional topological entities have been observed in both classical- and super-fluids, as well as in optical systems. In superconductors, they remained obscure due to their instability against collapse – unless supported by inhomogeneous magnetic field. Here we reveal a new kind of vortex matter in superconductors - the Josephson vortex loops - formed and stabilized in planar junctions or layered superconductors as a result of nontrivial cutting and recombination of Josephson vortices around the barriers for their motion. Engineering latter barriers opens broad perspectives on loop manipulation and control of other possible knotted/linked/entangled vortex topologies in nanostructured superconductors. In the context of Josephson devices proposed to date, the high-frequency excitations of the Josephson loops can be utilized in future design of powerful emitters, tunable filters and waveguides of high-frequency electromagnetic radiation, thereby pushing forward the much needed Terahertz technology.Other Information Published in: Scientific Reports
 License: http://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-018-21015-7
Development of Historical Enrolment Trends
Creators: name: Seitzer, Helen
name: Windzio, Michael
Publisher: name: Universität Bremen
Year: 2021
Subjects: subject: enrolment data
subject: 300

description: This technical paper gives an overview of our new data set on enrolment. most historical enrollment data can be contested, due to measurements, operations, and data quality. this dataset unites these different perspectives to provide researchers with the most plausible scenario of the development of recorded enrollment trends. The data set unites multiple sources on enrolment and therefore provides a trend line, describing how enrolment most likely evolved without claiming historical accuracy of a single data point. The significance of this contribution lies not in its historical representativeness but the comprehensiveness of this dataset. It includes 219 countries and provides data from 1820 to 2018. Overall, this dataset provides a good measurement for enrolment trends over a large country sample for a long period.
Characterization and Separation Performance of a Novel Polyethersulfone Membrane Blended with Acacia Gum
Creators: name: Manawi, Yehia
name: Kochkodan, Viktor
name: Mahmoudi, Ebrahim
name: Johnson, Daniel J.
name: Mohammad, Abdul Wahab
name: Atieh, Muataz Ali
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Materials engineering
subject: FOS: Materials engineering

description: Novel polyethersulfone (PES) membranes blended with 0.1–3.0 wt. % of Acacia gum (AG) as a pore-former and antifouling agent were fabricated using phase inversion technique. The effect of AG on the pore-size, porosity, surface morphology, surface charge, hydrophilicity, and mechanical properties of PES/AG membranes was studied by scanning electron microscopy (SEM), Raman spectroscopy, contact angle and zeta potential measurements. The antifouling -properties of PES/AG membranes were evaluated using Escherichia coli bacteria and bovine serum albumine (BSA). The use of AG as an additive to PES membranes was found to increase the surface charge, hydrophilicity (by 20%), porosity (by 77%) and permeate flux (by about 130%). Moreover, PES/AG membranes demonstrated higher antifouling and tensile stress (by 31%) when compared to pure PES membranes. It was shown that the prepared PES/AG membranes efficiently removed lead ions from aqueous solutions. Both the sieving mechanism of the membrane and chelation of lead with AG macromolecules incorporated in the membrane matrix contributed to lead removal. The obtained results indicated that AG can be used as a novel pore-former, hydrophilizing and antifouling agent, as well as an enhancer to the mechanical and rejection properties of the PES membranes.Other Information Published in: Scientific Reports
 License: http://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-017-14735-9
Stellar winds near massive black holes: The case of the S-stars
Creators: name: Lützgendorf, Nora
name: van der Helm, Edwin
name: Pelupessy, Inti
name: Zwart, Simon Portegies
Publisher: name: arXiv
Year: 2015
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Galactic center provides a unique laboratory to study the interaction of a supermassive black hole (SMBH) with its gaseous and stellar environment. Simulations to determine the accretion of stellar winds from the surrounding O-stars onto the black hole have been performed earlier, but in those the presence of the S-star system was ignored. The S-stars are a group of young massive B-stars in relatively close orbits around the black hole. Here we simulate those stars in order to study their contribution to the accretion rate, without taking the more distant and massive O-stars into account. We use the Astrophysical Multi-purpose Software Environment (AMUSE) to combine gravitational physics, stellar evolution and hydrodynamics in a single simulation of the S-stars orbiting the supermassive black hole, and use this framework to determine the amount of gas that is accreted onto the black hole. We find that the accretion rate is sensitive to the wind properties of the S-stars (rate of mass-loss and terminal velocity). Our simulations are consistent with the observed accretion rate of the black hole only if the stars exhibit high wind massloss rates that are comparable with those of evolved 7-10 Myr old stars with masses of M=19-25 M_SUN. This is in contrast with observations that have shown that these stars are rather young, main-sequence B-stars. We therefore conclude that the S-stars cannot account for the accretion rate alone.
description: 11 pages, 9 figures, 1 table, accepted for publication in MNRAS
Effect of disorder on transport properties in a tight-binding model for lead halide perovskites
Creators: name: Ashhab, S.
name: Voznyy, O.
name: Hoogland, S.
name: Sargent, E. H.
name: Madjet, M. E.
Publisher: name: Manara - Qatar Research Repository
Year: 2022
Subjects: subject: Materials engineering
subject: FOS: Materials engineering

description: The hybrid organic-inorganic lead halide perovskite materials have emerged as remarkable materials for photovoltaic applications. Their strengths include good electric transport properties in spite of the disorder inherent in them. Motivated by this observation, we analyze the effects of disorder on the energy eigenstates of a tight-binding model of these materials. In particular, we analyze the spatial extension of the energy eigenstates, which is quantified by the inverse participation ratio. This parameter exhibits a tendency, and possibly a phase transition, to localization as the on-site energy disorder strength is increased. However, we argue that the disorder in the lead halide perovskites corresponds to a point in the regime of highly delocalized states. Our results also suggest that the electronic states of mixed-halide materials tend to be more localized than those of pure materials, which suggests a weaker tendency to form extended bonding states in the mixed-halide materials and is therefore not favourable for halide mixing.Other Information Published in: Scientific Reports
 License: http://creativecommons.org/licenses/by/4.0
See article on publisher's website: http://dx.doi.org/10.1038/s41598-017-09442-4