bluuebunny/crossref_metadata_2025_split huggingface dataset:
Injection-limited and space charge-limited currents in organic semiconductor devices with nanopatterned metal electrodes
Authors: Buhl Janek , Lüder Hannes , Gerken Martina 
Published: September 2022

Abstract
Charge injection at metal-organic interfaces often limits the electric current in organic light-emitting diodes without additional injection layers. Integrated nanopatterned electrodes may provide a way to overcome this current injection limit by local field enhancements leading to locally space charge-limited currents. We compare electrical characteristics of planar and nanopatterned hole-only devices based on the charge transport material NPB with different thicknesses in order to investigate the nanopattern’s effect on the current limitation mechanism. Integration of a periodic nanograting into the metal electrode yields a current increase of about 1.5–4 times, depending on thickness and operating voltage. To verify the experimental results, we implement a finite element simulation model that solves the coupled Poisson and drift-diffusion equations in a weak form. It includes space charges, drift and diffusion currents, nonlinear mobility, and charge injection at the boundaries. We find in experiment and simulation that the planar devices exhibit injection-limited currents, whereas the currents in the nanopatterned devices are dominated by space charge effects, overcoming the planar injection limit. The simulations show space charge accumulations at the corners of the nanopattern, confirming the idea of locally space charge-limited currents.
Measuring the magnetic field of a low frequency LC-circuit with phyphox
Authors: Westermann N , Staacks S , Heinke H , Möhrke P 
Published: September 2022

Abstract
In high school, LC(R)-circuits are an integral component of physics education. We propose a new setup for exploring those circuits utilizing the magnetic field sensor of a smartphone in combination with the application phyphox, which reads and displays sensor input. Coils with high inductance and low resistance generate low frequency oscillations which can be visualized without any measuring devices other than a smartphone. The results are very satisfactory, because the resolution of the graph is high and the theoretical values match principal features of the measurements. Also, the setup can be achieved with low-cost components.
Manipulation of antichiral edge state based on modified Haldane model
Authors: Lü Xiao-Long , Yang Jia-En , Chen Huajin 
Published: September 2022

Abstract
Antichiral edge state (AES) was theoretical proposed by Colomés and Franz (2018 Phys. Rev. Lett.
120(8): 086603), which is recently realized in experiment. Under increasing the intensity of the off-resonant circularly polarized light, the AES can be induced as anisotropic, flat types and then anisotropic chiral edge state in zigzag honeycomb nanoribbon. More interestingly, the spin-polarized AESs can be further induced by the antiferromagnetic exchange field and electric field instead of the OPCP light. In particular, according to the propagating direction mismatch, we find the spin-degenerate (spin-polarized) dual propagating channel of the AES can be transformed into the spin-degenerate (spin-polarized) single propagating channel along the upper or lower boundary in topological heterojunction with different edge states. In the switch of the propagating channel, the local bond currents along the outer boundaries are reflected back in the lead and device with bulk states for spin-degenerate and spin polarized cases, respectively. In addition, these propagating channels are also robust against weak normal dephasing effect, which paves diverse platforms to design the topological devices in the future.
On the kinetic energy density functional: The limit of the density derivative order
Authors: Al-Aswad Abdulaziz H , Alharbi Fahhad H 
Published: September 2022

Abstract
Within ‘orbital-free’ density functional theory, it is essential to develop general kinetic energy density (KED), denoted as t(r). This is usually done by empirical corrections and enhancements, gradient expansions, machine learning, or axiomatic approaches to find forms that satisfy physical necessities. In all cases, it is crucial to determine the largest spatial density derivative order, m in, t(r). There have been many efforts to do so, but none have proven general or conclusive and there is no clear guide on how to set m. In this work, we found that, by imposing KED finitude away from V(r) singularities, m = D + 1 for systems of dimension D. This is consistent with observations and provides a needed guide for systematically developing more accurate semilocal KEDs.
2D- PhC based all optical AND, OR and EX-OR logic gates with high contrast ratio operating at C band
Authors: Geerthana S , Syedakbar S , Sridarshini T , Balaji V R , Sitharthan R , Shanmuga Sundar D 
Published: September 2022

Abstract
In this article, photonic crystal (PhC) based all-optical logic gates, namely AND, OR and EX-OR have been explored and their characteristics are reported. Two-dimensional (2D) PhC based logic gates are proposed using a hexagonal lattice with T-shaped structure by incorporating line defects. The total size of the device is 84 µm2 and it operates at a wavelength of 1550 nm (C band). The designed optical logic gates are investigated using 2D finite difference time domain simulators by means of the plane wave expansion method. Parameters, such as response time and contrast ratio of the designed all-optic logic gates, are analyzed. The proposed AND, OR and EX-OR logic gates offer a contrast ratio of 14.48 dB, 14.57 dB and 12.9 dB respectively with, in order, response times of 0.159 ps, 0.168 ps and 0.1672 ps. The designed logic gates work in the third optical window as they are operating at the 1550 nm wavelength. To specify the performance of the proposed logic gates, their field distribution has been determined and is exhibited. The designed logic gates are suitable for use in photonic integrated circuits, all optical computing and optical sensing applications.
Long-term reliability of GFRP reinforcement in concrete structures
Authors: Prokes J , Girgle F , Kostiha V , Bodnarova L , Bezdek O , Stepanek P 
Published: September 2022

Abstract
The article deals with the use of internal FRP (fibre reinforced polymer) reinforcement in concrete structures. In recent decades, the dynamically increasing number of applications in practice yields to the necessity to standardize test procedures, reliably determine short-term and, especially, long-term material characteristics. These are essential to the safe design of this modern material. Due to a lack of knowledge of the long-term behaviour, a substantive conservatism of the available design approaches arises. For this reason, the article deals mainly with the issue of determining the long-term reliability of FRP reinforcement in an aggressive environment with the simultaneous effect of the sustained load. Own findings from the performed long-term tests on the developed glass fibre reinforced polymer bars and experimentally obtained values will be presented.
Possibilities of using numerical modelling to determine the residual load capacity of concrete elements with composite reinforcement after fire
Authors: Prokes J , Rozsypalova I , Cairovic D , Girgle F , Sedlacek O , Danek P 
Published: September 2022

Abstract
During the service life of a structure, a number of phenomena occur that can affect the ability of the concrete structure to continue to perform its function. In the case of concrete load-bearing elements, fire and its effects represent significant influencing factor. Exposure to fire can, among other things, cause a great reduction of material properties of both concrete and reinforcement itself, but also affect their interaction. After a fire incident, it is necessary to assess the residual load capacity of the reinforced concrete elements. As part of the diagnostic work, material samples are usually taken from the structure after a fire. The purpose of the present paper was to investigate whether the experimentally obtained material characteristics can be used to verify the basic behaviour of concrete structures after fire. The structural material properties were used as input values for simplified numerical models of the structures. ATENA Cervenka Consulting software was chosen to construct a numerical model simulating the behaviour of the structural elements after exposure to fire loads. Finally, the effect of high temperatures on the residual load capacity of the beams determined by the numerical approach was compared with the experimental values of the load capacity of the beams after fire. The behaviour of concrete beams of dimensions 100 × 150 × 1800 mm reinforced with composite reinforcement was investigated. The specimens exposed to temperatures of 1000°C were subjected to mechanical bending tests after cooling to determine their residual load capacity.
Possibilities of using fly ash after denitrification to various types of building materials
Authors: Chromkova I , Kubatova D , Bohm P , Cechmanek R , Dzurov M , Kukletova I , Simbera T 
Published: September 2022

The paper summarises information gained within the verification of high-temperature fly ashes after the denitrification process. There was an examination of characteristics of fly ashes from various heat sources as well as possibilities of using these types of fly ashes to various types of building applications. An effect on final properties of a building material produced in laboratory or experimental conditions was observed.
Positive results were achieved within the verification of using fly ash to fly ash-cement mixtures. A quality of prepared suspensions was equal to the practically verified one prepared from a fly ash from a powerplant without SNCR. These mixtures after 28 days achieved compressive strengths 8 MPa. Significant increase of strengths in the course of time was recorded. After 90 days compressive strengths achieved values 13-16 MPa and after 1 year even 17-20 MPa. Flexural strengths after 28 days were around 1.5 MPa. This parameter also showed a tendency to increase in time.
Fly ash after denitrification was effective within a preparation of repairing materials based on epoxy resin. For these materials, 50% substitution of natural aggregate with fly ash after denitrification process was proven. Final strength characteristics of the new prepared material outperformed a reference mixture, containing only natural fine-grained aggregate/filler.
A using of fly ash as a compound of filler of alkali-activated systems was also tested. Fly ash after SNCR in the amount of 20 to 60% in combination with fine-milled blast furnace slag and sodium water glass was tested. These materials achieved compressive strengths 50–75 MPa and flexural strengths 6–10 MPa.
The verification of the possibility of alkalis penetration from the surrounding environment into the concrete pavement slabs
Authors: Dohnalkova B , Grosek J , Nevosad Z 
Published: September 2022

Abstract
The short material service life of concrete is currently a frequently discussed topic, especially for newly constructed roadways with cement concrete pavement. This early degradation of cement concrete pavement slabs is a major problem that threatens the service life of sub-sections or the entire road. As some partial results demonstrate, a possible cause of this degradation can be seen in the surrounding road environment, namely the possibility of transferring aggressive substances to the concrete pavement slab. This paper is concerned with the verification of the possibility of the penetration of alkalis penetration from the surrounding environment into the concrete pavement slab by simulating the effect of different external conditions and environments.
Monte Carlo simulations of vehicle-mounted whole-body NaI(Tl) counter
Authors: Mo H. , Gong P. , Liang D. , Wang Z. , Zhang J. , Hu Z. , Wu R. , Tang X. , Wang J. , Ma J. , Yang X. 
Published: September 2022

Abstract
During a nuclear emergency, an internal exposure detection
device with on-site and rapid measurements should be developed to
assess the level of internal exposure of people in radioactively
contaminated areas. Based on MCNP simulations, this work designed a
shielding structure of a NaI(Tl) type vehicle-mounted whole-body
counter (VM-WBC) and it has good shielding performance against the
background radiation. The mass of the shielding structure was less
than 800 kg, and the minimum detectable activity (MDA) of 60Co
and 137Cs obtained by simulation for a 10 min measurement was
less than 50 Bq. And we also study its counting efficiency
calibration by simulating radiation computing phantoms with Chinese
and American reference physiological characteristics. Equations that
fit counting efficiency, body build index, and photon energy were
also developed. The relative efficiency deviation between the
equation and the MCNP simulation was less than 5%.
Flapping dynamics of an inverted flag behind a cylinder
Authors: Ojo Oluwafemi , Kohtanen Eetu , Jiang Aojia , Brody Jacob , Erturk Alper , Shoele Kourosh 
Published: September 2022

Abstract
The inverted flag configuration is inspired by biological structures (e.g. leaves on a tree branch), showing rich dynamics associated with instabilities at lower flow speeds than the regular flag configuration. In the biological counterpart, the arrangement of leaves and twigs on foliage creates a complex interacting environment that promotes certain dynamic fluttering modes. While enabling a large amplitude response for reduced flow speeds is advantageous in emerging fields such as energy harvesting, still, little is known about the consequence of such interactions. In this work, we numerically study the canonical bio-inspired problem of the flow-structural interaction of a 2D inverted flag behind a cylindrical bluff body, mimicking a leaf behind a tree branch, to investigate its distinct fluttering regimes. The separation distance between the cylinder and flag is gradually modified to determine the effective distance beyond which small-amplitude or large-amplitude flapping occurs for different flow velocities. It is shown that the flag exhibits a periodic large amplitude−low frequency response mode when the cylinder is placed at a sufficiently large distance in front of the flag. At smaller distances, when the flag is within the immediate wake of the cylinder, the flag undergoes a high frequency−small amplitude response. Finally, the flag’s piezoelectric power harvesting capability is investigated numerically and experimentally for varying geometrical and electrical parameters associated with these two conditions. Two separate optimal response modes with the highest energy output have also been identified.
Derivation of Euler equations from quantum and classical microscopic dynamics
Authors: Hannani Amirali , Huveneers François 
Published: September 2022

Abstract
We derive Euler equations from a Hamiltonian microscopic dynamics. The microscopic system is a one-dimensional disordered harmonic chain, and the dynamics is either quantum or classical. This chain is an Anderson insulator with a symmetry protected mode: thermal fluctuations are frozen while the low modes ensure the transport of elongation, momentum and mechanical energy, that evolve according to Euler equations in an hyperbolic scaling limit. In this paper, we strengthen considerably the results in Bernardin et al (2019 Commun. Math. Phys.
365 215–37); Hannani (2022 Commun. Math. Phys.
390 349–23), where we established a limit in mean starting from a local Gibbs state: we now control the second moment of the fluctuations around the average, yielding a limit in probability, and we enlarge the class of admissible initial states.
Study the physical, chemical and biological changes in Um-Hawliyah drainage polluted with oil residues in Karbala Province-Iraq
Authors: Al-Yasari W.A. K. , Abdalakhwa S. H , Al-Alwani B. A. 
Published: September 2022

Abstract
This experiment was conducted to investigate the physical, chemical and biological parameters in Um-Hawliyah drainage which is contaminated with oil residues in the governorate of Karbala during the period from November,2015 to February,2016 in three stations. It was found that all physical and chemical properties were clearly affected by these wastes. During November and December, as the study stations varied in the proportions of physical, chemical and biological parameters, as observed in the variability in the number and types of bacteria and algae during the period and stations of study, as well as observed a clear increase in the effectiveness of enzymes superoxide dismutase (SOD) and Catalase (CAT) for Phragmites spp. plant during November at the second station. Each treatment with three replications, and all data were analyzed according SPSS statistics 17.0 software by (L.S.D 0.05).
Primary Productivity of Iraqi lakes: A Review
Authors: Wahhab Taibat A. , Hassan Fikrat M 
Published: September 2022

Abstract
Lentic ecosystems are important for fish production and are a critical habitat for waterfowl and numerous migratory birds. In this study we have gathered data on primary productivity of lakes across Iraq to provide updated information to strategize conservation and management. Tigris and Euphrates rivers are the primary sources of filling up major lakes in Iraq the overall assessment shows that the primary productivity is dependent on the algal composition and environmental factors with coincident role of macrophytes. An average of 37 to 637 mg carbon/m3/day of primary productivity was calculated for most of the lakes comprised of Bacillariophyceae and followed by Cyanophyceae, Chlorophyceae, Euglenophyceae, and Pyrrophyceae. It is hoped that this study can be an input to fill knowledge gaps and help to build long term maintainability of water quality and conservation of lake ecosystem across Iraq.
A Study of Some Aquatic Oligochaetes Community in Shatt Al-Hillah/ Middle of Iraq
Authors: Obaid Zahraa Hussein 
Published: September 2022

AbstractThe current study discusses the spatial distribution of Oligochaete communities on Shatt Al-Hillah. Monthly samples of Oligochaete worms were gathered from four locations along the Shatt Al-Hillah in the middle of Iraq, between September 2019 and May 2020. show the study for the existence of521Individual aquatic Oligochaeta belong to 7 species from the Naididae and Lumriculdae subfamilies, as well as the Pristinae subfamily, and in Site S3 had the largest number of worms, with 180 worms from 7 species being detected, while in Site S2 had the least number of worms, 107 from 5 species. The largest individual numbers were registered in February, while the lowest were recorded in April. The species, Prisma aequiseta, was first recorded, in the Shatt Al-Hillah rive. Show tubificid worms, Branchuira sowerbyi, and Limnodrilus hoffmeisteri were the most abundant species in the Shatt Al-Hillah.
Heavy metals pollution profiles in Tigris River within Baghdad city
Authors: Aljanabi Zahraa Zahraw , Hassan Fikrat M. , Jawad Al-Obaidy Abdul-Hameed M. 
Published: September 2022

Abstract
The Tigris River is a major source of Iraq’s drinking and agricultural water supply. An increase in pollution by heavy metals can be a great threat to human and aquatic life. In this study, the pollution index (PI) and metal index (MI) were used to evaluate the status of the Tigris River in Baghdad City. Five stations were chosen to conduct the study. Five heavy metals were analyzed: iron (Fe), lead (Pb), nickel (Ni), zinc (Zn), and chromium (Cr). The result of PI was ranked between “No effect to moderately affected for Fe; Slightly Affected to Seriously Affected for Pb; no effect to moderately affected for Ni, and no effect to strongly affected for Cr; only Zn was in the No effect class. While the Metal Index (MI) exceeded the warning threshold on all sites, its results ranged between 2.85 and 5.89. Pb was the most significant element that caused the rise of both indices where their values exceeded the allowable limits all the time, followed by Fe and Ni. increasing the concentration of heavy metals in the Tigris River, which returns to effluents of waste from many industrial facilities located on its bank, and the direct discharge of public sewage.
Water decolourisation using a phytoremediation method: Ocimum basilicum as model
Authors: Al-Saffar Abdulkareem K. I. , Attaee Muammar H. , kadhum Zainab Akeel , Abood Emad Salaam , Samaka Isra’a S. , Al-Sareji Osamah J. 
Published: September 2022

Abstract
Phytoremediation is the utilisation of plants to remove pollutants from a polluted media, such as soils and water. This method is an eco-friendly approach because it remediates water or soil from pollutants without chemical treatments or a chemical pre-treatment. For this reason, this method was used in this study to decolourise artificial water from a textile dye (methyl orange (MO)). The phytoremediation process was done using the Ocimum basilicum plant and continued for 30 days. The Ocimum basilicum plants were placed in plastic enclosures and exposed to 5 litres of coloured water (25 mg/L and 50 mg/L of OM) for the required duration. The enclosures were kept in a greenhouse with a controlled temperature (27±2°C), and 100 mL samples were taken from the enclosures every two days. The experiments showed that 1) the Ocimum basilicum plant removed 90% of the MO after 24 days when the MO dye concentration of 25 mg and 2) the MO dye in water decreases the relative growth rate of the Ocimum basilicum plant. This study concluded that the Ocimum basilicum plant is a promising alternative to removing dyes from water and should be adopted to reduce the effects of water pollution on the environment.
A divide-and-conquer method to improve performance in quantum transport calculations: conductance in rotated graphene nanoribbons side-contact junctions
Authors: Rodríguez Mauricio J , Ramírez Carlos 
Published: September 2022

Abstract
We propose a divide-and-conquer algorithm to find recursively the scattering matrix of general tight-binding structures. The scattering matrix allows a direct calculation of transport properties in mesoscopic systems by using the Landauer formula. The method is exact, and by analyzing the performance of the algorithm in square, triangular and honeycomb lattices, we show a significant improvement in comparison to other state-of-the-art recursive and non-recursive methods. We utilize this algorithm to compute the conductance of a rotated graphene nanoribbon side-contact junction, revealing that for electrons with energies smaller than −2.7 eV the transmission function depends negligibly on the angle of the junction, whereas for electrons with energies greater than −2.7 eV, there exists a set of angles for the system that increase its conductance independently of the energy of the particles.