SwePub - search: WFRF:(Negi A.)

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1.	Abbasi, R., et al. (author) Citizen science for IceCube: Name that Neutrino 2024 In: European Physical Journal Plus. - 2190-5444. ; 139:6 Journal article (peer-reviewed)abstract Name that Neutrino is a citizen science project where volunteers aid in classification of events for the IceCube Neutrino Observatory, an immense particle detector at the geographic South Pole. From March 2023 to September 2023, volunteers did classifications of videos produced from simulated data of both neutrino signal and background interactions. Name that Neutrino obtained more than 128,000 classifications by over 1800 registered volunteers that were compared to results obtained by a deep neural network machine-learning algorithm. Possible improvements for both Name that Neutrino and the deep neural network are discussed.
2.	Abbasi, R., et al. (author) Search for Continuous and Transient Neutrino Emission Associated with IceCube's Highest-energy Tracks: An 11 yr Analysis 2024 In: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 964:1 Journal article (peer-reviewed)abstract IceCube alert events are neutrinos with a moderate-to-high probability of having astrophysical origin. In this study, we analyze 11 yr of IceCube data and investigate 122 alert events and a selection of high-energy tracks detected between 2009 and the end of 2021. This high-energy event selection (alert events + high-energy tracks) has an average probability of >= 0.5 of being of astrophysical origin. We search for additional continuous and transient neutrino emission within the high-energy events' error regions. We find no evidence for significant continuous neutrino emission from any of the alert event directions. The only locally significant neutrino emission is the transient emission associated with the blazar TXS 0506+056, with a local significance of 3 sigma, which confirms previous IceCube studies. When correcting for 122 test positions, the global p-value is 0.156 and compatible with the background hypothesis. We constrain the total continuous flux emitted from all 122 test positions at 100 TeV to be below 1.2 x 10-15 (TeV cm2 s)-1 at 90% confidence assuming an E -2 spectrum. This corresponds to 4.5% of IceCube's astrophysical diffuse flux. Overall, we find no indication that alert events in general are linked to lower-energetic continuous or transient neutrino emission.
3.	Abbasi, R., et al. (author) Search for decoherence from quantum gravity with atmospheric neutrinos 2024 In: Nature Physics. - 1745-2481 .- 1745-2473. ; 20:6, s. 913-920 Journal article (peer-reviewed)abstract Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.
4.	Abbasi, R., et al. (author) Search for 10-1000 GeV Neutrinos from Gamma-Ray Bursts with IceCube 2024 In: Astrophysical Journal. - : Institute of Physics (IOP). - 1538-4357 .- 0004-637X. ; 964:2 Journal article (peer-reviewed)abstract We present the results of a search for 10-1000 GeV neutrinos from 2268 gamma-ray bursts (GRBs) over 8 yr of IceCube-DeepCore data. This work probes burst physics below the photosphere where electromagnetic radiation cannot escape. Neutrinos of tens of giga electronvolts are predicted in sub-photospheric collision of free-streaming neutrons with bulk-jet protons. In a first analysis, we searched for the most significant neutrino-GRB coincidence using six overlapping time windows centered on the prompt phase of each GRB. In a second analysis, we conducted a search for a group of GRBs, each individually too weak to be detectable, but potentially significant when combined. No evidence of neutrino emission is found for either analysis. The most significant neutrino coincidence is for Fermi-GBM GRB bn 140807500, with a p-value of 0.097 corrected for all trials. The binomial test used to search for a group of GRBs had a p-value of 0.65 after all trial corrections. The binomial test found a group consisting only of GRB bn 140807500 and no additional GRBs. The neutrino limits of this work complement those obtained by IceCube at tera electronvolt to peta electronvolt energies. We compare our findings for the large set of GRBs as well as GRB 221009A to the sub-photospheric neutron-proton collision model and find that GRB 221009A provides the most constraining limit on baryon loading. For a jet Lorentz factor of 300 (800), the baryon loading on GRB 221009A is lower than 3.85 (2.13) at a 90% confidence level.
5.	Abbasi, R., et al. (author) Search for Galactic Core-collapse Supernovae in a Decade of Data Taken with the IceCube Neutrino Observatory 2024 In: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 1538-4357 .- 0004-637X. ; 961:1 Journal article (peer-reviewed)abstract The IceCube Neutrino Observatory has been continuously taking data to search for O(0.5–10) s long neutrino bursts since 2007. Even if a Galactic core-collapse supernova is optically obscured or collapses to a black hole instead of exploding, it will be detectable via the O(10) MeV neutrino burst emitted during the collapse. We discuss a search for such events covering the time between 2008 April 17 and 2019 December 31. Considering the average data taking and analysis uptime of 91.7% after all selection cuts, this is equivalent to 10.735 yr of continuous data taking. In order to test the most conservative neutrino production scenario, the selection cuts were optimized for a model based on an 8.8 solar mass progenitor collapsing to an O–Ne–Mg core. Conservative assumptions on the effects of neutrino oscillations in the exploding star were made. The final selection cut was set to ensure that the probability to detect such a supernova within the Milky Way exceeds 99%. No such neutrino burst was found in the data after performing a blind analysis. Hence, a 90% C.L. upper limit on the rate of core-collapse supernovae out to distances of ≈25 kpc was determined to be 0.23 yr−1. For the more distant Magellanic Clouds, only high neutrino luminosity supernovae will be detectable by IceCube, unless external information on the burst time is available. We determined a model-independent limit by parameterizing the dependence on the neutrino luminosity and the energy spectrum.
6.	Gannon, J., et al. (author) ARFGAP1 Is Dynamically Associated with Lipid Droplets in Hepatocytes 2014 In: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 9:11 Journal article (peer-reviewed)abstract The ARF GTPase Activating Protein 1 (ARFGAP1) associates mainly with the cytosolic side of Golgi cisternal membranes where it participates in the formation of both COPI and clathrin-coated vesicles. In this study, we show that ARFGAP1 associates transiently with lipid droplets upon addition of oleate in cultured cells. Also, that addition of cyclic AMP shifts ARFGAP1 from lipid droplets to the Golgi apparatus and that overexpression and knockdown of ARFGAP1 affect lipid droplet formation. Examination of human liver tissue reveals that ARFGAP1 is found associated with lipid droplets at steady state in some but not all hepatocytes.
7.	Lensink, Marc F., et al. (author) Impact of AlphaFold on structure prediction of protein complexes: The CASP15-CAPRI experiment 2023 In: Proteins. - : WILEY. - 0887-3585 .- 1097-0134. Journal article (peer-reviewed)abstract We present the results for CAPRI Round 54, the 5th joint CASP-CAPRI protein assembly prediction challenge. The Round offered 37 targets, including 14 homodimers, 3 homo-trimers, 13 heterodimers including 3 antibody-antigen complexes, and 7 large assemblies. On average similar to 70 CASP and CAPRI predictor groups, including more than 20 automatics servers, submitted models for each target. A total of 21 941 models submitted by these groups and by 15 CAPRI scorer groups were evaluated using the CAPRI model quality measures and the DockQ score consolidating these measures. The prediction performance was quantified by a weighted score based on the number of models of acceptable quality or higher submitted by each group among their five best models. Results show substantial progress achieved across a significant fraction of the 60+ participating groups. High-quality models were produced for about 40% of the targets compared to 8% two years earlier. This remarkable improvement is due to the wide use of the AlphaFold2 and AlphaFold2-Multimer software and the confidence metrics they provide. Notably, expanded sampling of candidate solutions by manipulating these deep learning inference engines, enriching multiple sequence alignments, or integration of advanced modeling tools, enabled top performing groups to exceed the performance of a standard AlphaFold2-Multimer version used as a yard stick. This notwithstanding, performance remained poor for complexes with antibodies and nanobodies, where evolutionary relationships between the binding partners are lacking, and for complexes featuring conformational flexibility, clearly indicating that the prediction of protein complexes remains a challenging problem.
8.	Shahcheraghi, Seyed H., et al. (author) Gene Therapy for Neuropsychiatric Disorders : Potential Targets and Tools 2023 In: CNS & Neurological Disorders. - : Bentham Science Publishers. - 1871-5273 .- 1996-3181. ; 22:1, s. 51-65 Research review (peer-reviewed)abstract Neuropsychiatric disorders that affect the central nervous system cause considerable pressures on the health care system and have a substantial economic burden on modern societies. The present treatments based on available drugs are mostly ineffective and often costly. The molecular process of neuropsychiatric disorders is closely connected to modifying the genetic structures inherited or caused by damage, toxic chemicals, and some current diseases. Gene therapy is presently an experimental concept for neurological disorders. Clinical applications endeavor to alleviate the symptoms, reduce disease progression, and repair defective genes. Implementing gene therapy in inherited and acquired neurological illnesses entails the integration of several scientific disciplines, including virology, neurology, neurosurgery, molecular genetics, and immunology. Genetic manipulation has the power to minimize or cure illness by inducing genetic alterations at endogenous loci. Gene therapy that involves treating the disease by deleting, silencing, or editing defective genes and delivering genetic material to produce therapeutic molecules has excellent potential as a novel approach for treating neuropsychiatric disorders. With the recent advances in gene selection and vector design quality in targeted treatments, gene therapy could be an effective approach. This review article will investigate and report the newest and the most critical molecules and factors in neuropsychiatric disorder gene therapy. Different genome editing techniques available will be evaluated, and the review will highlight preclinical research of genome editing for neuropsychiatric disorders while also evaluating current limitations and potential strategies to overcome genome editing advancements.
9.	Aljabali, Alaa A. A., et al. (author) The viral capsid as novel nanomaterials for drug delivery 2021 In: Future Science OA. - : Future Science Ltd. - 2056-5623. ; 7:9 Research review (peer-reviewed)abstract The purpose of this review is to highlight recent scientific developments and provide an overview of virus self-assembly and viral particle dynamics. Viruses are organized supramolecular structures with distinct yet related features and functions. Plant viruses are extensively used in biotechnology, and virus-like particulate matter is generated by genetic modification. Both provide a material-based means for selective distribution and delivery of drug molecules. Through surface engineering of their capsids, virus-derived nanomaterials facilitate various potential applications for selective drug delivery. Viruses have significant implications in chemotherapy, gene transfer, vaccine production, immunotherapy and molecular imaging. Lay abstract: The purpose of this review is to highlight recent scientific developments and provide an overview of virus self-assembly and viral particle dynamics. Viruses are organized supramolecular structures with distinct yet related features and functions. Plant viruses are extensively used in biotechnology, and virus-like particulate matter is generated by genetic modification. Both provide a material-based means for selective distribution and delivery of drug molecules. Through surface engineering of their capsids, virus-derived nanomaterials facilitate various potential applications for selective drug delivery. Viruses have significant implications in chemotherapy, gene transfer, vaccine production, immunotherapy and molecular imaging. Here we performed a comprehensive database search to review findings in this area, demonstrating that viral nanostructures possess unique properties that make them ideal for applications in diagnostics, cell labeling, contrasting agents and drug delivery structures.
10.	Armejach, A., et al. (author) Techniques to Improve Performance in Requester-Wins Hardware Transactional Memory 2013 In: Transactions on Architecture and Code Optimization. - 1544-3973 .- 1544-3566. ; 10:4, s. articlenr, 42- Journal article (peer-reviewed)abstract The simplicity of requester-wins Hardware Transactional Memory (HTM) makes it easy to incorporate in existing chip multiprocessors. Hence, such systems are expected to be widely available in the near future. Unfortunately, these implementations are prone to suffer severe performance degradation due to transient and persistent livelock conditions. This article shows that existing techniques are unable to mitigate this degradation effectively. It then proposes and evaluates four novel techniques-two software-based that employ information provided by the hardware and two that require simple core-local hardware additions-which have the potential to boost the performance of requester-wins HTM designs substantially.
11.	Negi, A., et al. (author) A Multiphysics Model for Assessing Casing Integrity in Sour Service Applications 2023 In: Society of Petroleum Engineers - ADIPEC, ADIP 2023. - : Society of Petroleum Engineers (SPE). Conference paper (peer-reviewed)abstract Structural integrity assessments are vital for ensuring the safety and efficiency of oil and gas wells, especially in sour service applications. The casings used in drilling operations are critical as mechanical barriers against leaks among different well-construction components. However, their susceptibility to environment-assisted crack growth, like sulfide stress cracking (SSC), presents challenges for casing mechanical integrity management. Conventional analytical methods are quick but can be overly conservative in material selection. Recently, multiphysics modelling of fracture has emerged as an accurate simulation approach, leveraging tools such as hydrogen diffusion models, fracture mechanics, and finite element analysis. In this work, a coupled deformation-diffusion phase-field finite element framework is used to model SSC nucleation and growth in a sour environment. The multiphysics model employs coupling between structural deformation, hydrogen diffusion due to H2S exposure, and fracture processes to simulate SSC. The numerical results show good agreement with the experimental data for different levels of H2S exposure. A numerical study is also conducted to study SSC nucleation and growth in pre-notched mini-pipe subjected to internal pressure and H2S exposure. The findings of this investigation provide valuable insights into the effectiveness of a coupled phase-field approach to study the combined role of stresses and through-wall hydrogen gradients on pipe failure.
12.	Negi, Anurag, 1980, et al. (author) Transactional prefetching: Narrowing the window of contention in hardware transactional memory 2012 In: Parallel Architectures and Compilation Techniques - Conference Proceedings, PACT. - New York, NY, USA : ACM. - 1089-795X. ; , s. 181-190 Conference paper (peer-reviewed)abstract Memory access latency is the primary performance bottle-neck in modern computer systems. Prefetching data before it is needed by a processing core allows substantial performance gains by overlapping significant portions of memory latency with useful work. Prior work has investigated this technique and measured potential benefits in a variety of scenarios. However, its use in speeding up Hardware Transactional Memory (HTM) has remained hitherto unexplored. In several HTM designs transactions invalidate speculatively updated cache lines when they abort. Such cache lines tend to have high locality and are likely to be accessed again when the transaction re-executes. Coarse grained transactions that update several cache lines are particularly susceptible to performance degradation even under moderate contention. However, such transactions show strong locality of reference, especially when contention is high. Prefetching cache lines with high locality can, therefore, improve overall concurrency by speeding up transactions and, thereby, narrowing the window of time in which such transactions persist and can cause contention. Such transactions are important since they are likely to form a common TM use-case. We note that traditional prefetch techniques may not be able to track such lines adequately or issue prefetches quickly enough. This paper investigates the use of prefetching in HTMs, proposing a simple design to identify and request prefetch candidates, and measures performance gains to be had for several representative TM workloads.
13.	Shrivastava, Garima, et al. (author) Targeting LIN28 : a new hope in prostate cancer theranostics 2021 In: Future Oncology. - : Future Medicine. - 1479-6694 .- 1744-8301. ; 17:29, s. 3873-3880 Journal article (peer-reviewed)abstract The mortality and morbidity rates for prostate cancer have recently increased to alarming levels, rising higher than lung cancer. Due to a lack of drug targets and molecular probes, existing theranostic techniques are limited. Human LIN28A and its paralog LIN28B overexpression are associated with a number of tumors resulting in a remarkable increase in cancer aggression and poor prognoses. The current review aims to highlight recent work identifying the key roles of LIN28A and LIN28B in prostate cancer, and to instigate further preclinical and clinical research in this important area.
14.	Tamhankar, AJ, et al. (author) Characteristics of a Nationwide Voluntary Antibiotic Resistance Awareness Campaign in India; Future Paths and Pointers for Resource Limited Settings/Low and Middle Income Countries 2019 In: International journal of environmental research and public health. - : MDPI AG. - 1660-4601. ; 16:24 Journal article (peer-reviewed)abstract Antibiotic resistance has reached alarming proportions globally, prompting the World Health Organization to advise nations to take up antibiotic awareness campaigns. Several campaigns have been taken up worldwide, mostly by governments. The government of India asked manufacturers to append a ‘redline’ to packages of antibiotics as identification marks and conducted a campaign to inform the general public about it and appropriate antibiotic use. We investigated whether an antibiotic resistance awareness campaign could be organized voluntarily in India and determined the characteristics of the voluntarily organized campaign by administering a questionnaire to the coordinators, who participated in organizing the voluntary campaign India. The campaign characteristics were: multiple electro–physical pedagogical and participatory techniques were used, 49 physical events were organized in various parts of India that included lectures, posters, booklet/pamphlet distribution, audio and video messages, competitions, and mass contact rallies along with broadcast of messages in 11 local languages using community radio stations (CRS) spread all over India. The median values for campaign events were: expenditure—3000 Indian Rupees/day (US$~47), time for planning—1 day, program spread—4 days, program time—4 h, direct and indirect reach of the message—respectively 250 and 500 persons/event. A 2 min play entitled ‘Take antibiotics as prescribed by the doctor’ was broadcast 10 times/day for 5 days on CRS with listener reach of ~5 million persons. More than 85%ofcoordinators thought that the campaign created adequate awareness about appropriate antibiotic use and antibiotic resistance. The voluntary campaign has implications for resource limited settings/low and middle income countries.
15.	Ando, Y, et al. (author) Impact of cysteine (Cys)-conjugation and pH on amyloid formation of wild type and Met30 transthyretin (TTR) 1999 In: Amyloid and Amyloidosis 1998. - : Parthenon, New York. ; , s. 44- Book chapter (other academic/artistic)
16.	Bajard, L, et al. (author) Application of AOPs to assist regulatory assessment of chemical risks - Case studies, needs and recommendations 2023 In: Environmental research. - : Elsevier BV. - 1096-0953 .- 0013-9351. ; 217, s. 114650- Journal article (peer-reviewed)
17.	Bhattacharya, S., et al. (author) Evolution of collectivity and evidence of octupole correlations in Br 73 2019 In: Physical Review C. - 2469-9985. ; 100:1 Journal article (peer-reviewed)abstract High-spin states in the Br73 nucleus have been populated via the Cr50(Si28,αp)Br73 fusion evaporation reaction with a beam energy of 90 MeV. The deexciting gamma rays were detected using the Indian National Gamma Array (INGA). Using the γ-γ coincidence technique, two new bands and eight new interconnecting transitions have been added. The strong interconnecting E1 transitions, between positive and negative parity bands, ensure the existence of octupole correlations at low spin. Line shapes have been observed for 17 transitions, which were analyzed by the Doppler-shift attenuation method to determine the lifetime of excited states of the yrast negative parity band and its signature partner band along with the positive parity band. The deduced transitional quadrupole moments Qt for the ground state band decrease with increasing spin, with their values ranging from 2.88 to 1.00 eb. A similar trend in the quadrupole moment has also been observed for the signature partner as well as for the positive parity band. This decrease in Qt with increasing spin for these bands is interpreted in terms of the cranked Nilsson-Strutinsky model and total Routhian surface calculations, which indicate possible band termination at higher spin.
18.	Goel, Bhavishya, 1981, et al. (author) Performance and energy analysis of the restricted transactional memory implementation on haswell 2014 In: Proceedings of the International Parallel and Distributed Processing Symposium, IPDPS. - 2332-1237. - 9780769552071 ; , s. 615-624 Conference paper (peer-reviewed)abstract Hardware transactional memory implementations are becoming increasingly available. For instance, the Intel Core i7 4770 implements Restricted Transactional Memory (RTM) support for Intel Transactional Synchronization Extensions (TSX). In this paper, we present a detailed evaluation of RTM performance and energy expenditure. We compare RTM behavior to that of the TinySTM software transactional memory system, first by running micro benchmarks, and then by running the STAMP benchmark suite. We find that which system performs better depends heavily on the workload characteristics. We then conduct a case study of two STAMP applications to assess the impact of programming style on RTM performance and to investigate what kinds of software optimizations can help overcome RTM's hardware limitations.
19.	Kern, Simon, et al. (author) Direct numerical simulations of an airfoil undergoing dynamic stall at different background disturbance levels 2024 In: Journal of Fluid Mechanics. - : Cambridge University Press (CUP). - 0022-1120 .- 1469-7645. ; 986 Journal article (peer-reviewed)abstract Thin airfoil dynamic stall at moderate Reynolds numbers is typically linked to the sudden bursting of a small laminar separation bubble close to the leading edge. Given the strong sensitivity of laminar separation bubbles to external disturbances, the onset of dynamic stall on a NACA0009 airfoil section subject to different levels of low-amplitude free stream disturbances is investigated using direct numerical simulations. The flow is practically indistinguishable from clean inflow simulations in the literature for turbulence intensities at the leading edge of Tu = 0.02 %. At slightly higher turbulence intensities of Tu = 0.05 %, the bursting process is found to be considerably less smooth and strong coherent vortex shedding from the laminar separation bubble is observed prior to the formation of the dynamic stall vortex (DSV). This phenomenon is considered in more detail by analysing its appearance in an ensemble of simulations comprising statistically independent realisations of the flow, thus proving its statistical relevance. In order to extract the transient dynamics of the vortex shedding, the classical proper orthogonal decomposition method is generalised to include time in the energy measure and applied to the time-resolved simulation data of incipient dynamic stall. Using this technique, the dominant transient spatiotemporally correlated features are distilled and the wave train of the vortex shedding prior to the emergence of the main DSV is reconstructed from the flow data exhibiting dynamics of large-scale coherent growth and decay within the turbulent boundary layer.
20.	Negi, Devendra, et al. (author) Coexisting commensurate and incommensurate charge ordered phases in CoO 2021 In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 11:1 Journal article (peer-reviewed)abstract The subtle interplay of strong electronic correlations in a distorted crystal lattice often leads to the evolution of novel emergent functionalities in the strongly correlated materials (SCM). Here, we unravel such unprecedented commensurate (COM) and incommensurate (ICOM) charge ordered (CO) phases at room temperature in a simple transition-metal mono-oxide, namely CoO. The electron diffraction pattern unveils a COM (q(1) = 1/2 (1, 1, (1) over bar) and ICOM (q(2) = 0.213(1, 1, (1) over bar)) periodic lattice distortion. Transmission electron microscopy (TEM) captures unidirectional and bidirectional stripe patterns of charge density modulations. The widespread phase singularities in the phase-field of the order parameter (OP) affirms the abundant topological disorder. Using, density functional theory (DFT) calculations, we demystify the underlying electronic mechanism. The DFT study shows that a cation disordering (Co1-x O, with x = 4.17%) stabilizes Jahn-Teller (JT) distortion and localized aliovalent Co3+ states in CoO. Therefore, the lattice distortion accompanied with mixed valence states (Co3+, Co2+) states introduces CO in CoO. Our findings offer an electronic paradigm to engineer CO to exploit the associated electronic functionalities in widely available transition-metal mono-oxides.
21.	Negi, Devendra Singh, et al. (author) Prospect for detecting magnetism of a single impurity atom using electron magnetic chiral dichroism 2019 In: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 100:10 Journal article (peer-reviewed)abstract Dopants, even single atoms, can influence the electrical and magnetic properties of materials. Here we demonstrate the opportunity for detecting the magnetic response of an embedded magnetic impurity in a nonmagnetic host material. We combine a depth sectioning approach with electron magnetic circular dichroism in scanning transmission electron microscopy to compute the depth-resolved magnetic inelastic-scattering cross section of single Co impurity buried in the host crystal of GaAs. Our calculations suggest that the magnetic dichroic signal intensity is sensitive to the depth and lateral position of the electron probe relative to the magnetic impurity. Additionally, a more precise dichroic signal localization can be achieved via choosing higher-collection-angle (beta) apertures. Quantitative evaluation of the inelastic-scattering cross section and signal-to-noise ratio indicates that the magnetic signal from a single Co atom is on the verge of being detectable with today's state-of-the-art instrumentation.
22.	Negi, Devendra Singh, et al. (author) Spin-entropy induced thermopower and spin-blockade effect in CoO 2019 In: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 100:14 Journal article (peer-reviewed)abstract We report spin-entropy-induced thermopower and the occurrence of a spin-blockade effect in stoichiometric disordered CoO. Cation defect-driven distortion in the octahedral ligand field of CoO leads to a charge transfer process and favors the stabilization of Co+3 charge states at defect adjacent atomic sites. Moreover, a higher extent of local stoichiometric disruption triggers the spin crossover and magnetic collapse into a Co+3 state. Degenerated spin-orbital states on vacancy neighbored atomic sites render the spin-orbital degeneracy to enhance the thermopower in CoO. Furthermore, we unravel an operating spin-blockade effect in CoO. The localized combination of active magnetic states-high-spin Co+2 and neutral magnetic states-low-spin Co+3 on alternate atomic sites suppress the charge carrier hopping due to a spin blockade. In the pursuit of efficient thermoelectric material, the present investigation explores the potential of the recipe of spin entropy and defect-engineered CoO.
23.	Roland, Steffen, et al. (author) Equilibrated Charge Carrier Populations Govern Steady-State Nongeminate Recombination in Disordered Organic Solar Cells 2019 In: The Journal of Physical Chemistry Letters. - : AMER CHEMICAL SOC. - 1948-7185. ; 10:6, s. 1374-1381 Journal article (peer-reviewed)abstract We employed bias-assisted charge extraction techniques to investigate the transient and steady-state recombination of photogenerated charge carriers in complete devices of a disordered polymer-fullerene blend. Charge recombination is shown to be dispersive, with a significant slowdown of the recombination rate over time, consistent with the results from kinetic Monte Carlo simulations. Surprisingly, our experiments reveal little to no contributions from early time recombination of nonequilibrated charge carriers to the steady-state recombination properties. We conclude that energetic relaxation of photogenerated carriers outpaces any significant nongeminate recombination under application-relevant illumination conditions. With equilibrated charges dominating the steady-state recombination, quasi-equilibrium concepts appear suited for describing the open-circuit voltage of organic solar cells despite pronounced energetic disorder.
24.	Vats, Nilesh, et al. (author) Catalyzing Bond-Dissociation in Graphene via Alkali-Iodide Molecules 2021 In: Small. - : John Wiley & Sons. - 1613-6810 .- 1613-6829. ; 17:42 Journal article (peer-reviewed)abstract Atomic design of a 2D-material such as graphene can be substantially influenced by etching, deliberately induced in a transmission electron microscope. It is achieved primarily by overcoming the threshold energy for defect formation by controlling the kinetic energy and current density of the fast electrons. Recent studies have demonstrated that the presence of certain species of atoms can catalyze atomic bond dissociation processes under the electron beam by reducing their threshold energy. Most of the reported catalytic atom species are single atoms, which have strong interaction with single-layer graphene (SLG). Yet, no such behavior has been reported for molecular species. This work shows by experimentally comparing the interaction of alkali and halide species separately and conjointly with SLG, that in the presence of electron irradiation, etching of SLG is drastically enhanced by the simultaneous presence of alkali and iodine atoms. Density functional theory and first principles molecular dynamics calculations reveal that due to charge-transfer phenomena the C-C bonds weaken close to the alkali-iodide species, which increases the carbon displacement cross-section. This study ascribes pronounced etching activity observed in SLG to the catalytic behavior of the alkali-iodide species in the presence of electron irradiation.

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