bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure, texture, and instability during superplastic deformation of ECAP-treated AZ31 Mg alloy
Authors: Fatemi S. M. , Paul H. , Hemmati-Hosuri A.
Published: February 2023

An ultrafine-grained AZ31 Mg alloy processed through multipass equal channel angular pressing (ECAP) achieved 5 and 0.9 µm mean grain sizes after two and four passes, respectively. The deformation behaviour of the alloy was studied through tensile testing at high temperatures. A 410% superplastic elongation was achieved at 250°C during the tensile deformation of the four-pass-processed alloy. The Haehner criterion allowed the prediction of the stable uniform deformation of the alloy. The strain rate sensitivity of 0.38 and equiaxed microstructure suggested grain boundary sliding as the rate-controlling mechanism. The slip system's contribution to superplasticity was discussed using related Schmid factors. Slip activity prevalence at high strains induced a texture-strengthening effect and allowed low-angle grain boundary formation at high strains.
Comparative analysis of aluminium core honeycomb with 3D woven Kevlar honeycomb composite
Authors: Tripathi Lekhani , Behera Bijoya Kumar
Published: February 2023

Sandwich structures have a high capacity for stiffness, strength, and energy absorption, and are frequently used as lightweight composite components in shipbuilding and aeronautical engineering. In this work, mechanical characterisation of aluminium honeycomb and 3D-woven Kevlar honeycomb composite sandwich panels with respect to their flatwise, edgewise compression, and three-point bending tests was carried out. The experimental results show that the 3D-woven Kevlar honeycomb is better than the aluminium honeycomb for flatwise and three-point bending behaviour. In the case of edgewise compression, aluminium honeycomb shows significant results. Aluminium honeycomb cores show the plastic collapse mechanism, while Kevlar honeycomb indicates the occurrence of buckling before failure.
Constructing a family of conformally flat scalar field models
Authors: Apostolopoulos Pantelis S
Published: February 2023

Using purely geometrical methods we present a mechanism to solve the scalar field equations of motion (non-minimally coupled with gravity) in a spherically symmetric background. We found that the full set of spacetimes, which are of Petrov type O (conformally flat) and admit a gradient conformal vector field, can be determined completely. It is shown that the full group of scalar field equations reduced to a single equation that depends only on the distance

w
=

r

2

−

t

2

leaving the metric function (equivalently the functional form of the scalar field or the potential) freely chosen. Depending on the structure of the metric or the potential V (as a function of φ) a solution can be found either analytically or via numerical integration. We provide physically sound examples and prove that (Anti)-de Sitter fits this scheme. We also reconstruct a recently found solution (Strumia and Tetradis 2022 J. High Energy Phys. JHEP09(2022)203) representing an expanding scalar bubble with metric that has a singularity and corresponds to what is termed as Anti-de Sitter crunch.
The envelope theory as a pedagogical tool
Authors: Semay Claude , Balcaen Maud
Published: February 2023

The envelope theory (ET) is a reliable and easy to implement method to solve time independent Schrödinger-like equations (eigenvalues and eigenvectors). It is particularly useful to solve many-body systems since the computational cost is independent from the number of particles. The purpose of this paper is twofold. First, we want to make known a method that is probably too little used. Second, we also want to show that this method can be used as a pedagogical tool, thanks to its simplicity and the reliable results that can be obtained. To reach these goals, the ET is applied to a simple problem in one dimension, the soft-Coulomb potential

−
k

/

x

2

+

d

2

, characterised by a bias distance d. Such interaction is used for the study of excitons, electron–hole bound pairs where the two charges are kept separated in two different one-dimensional regions (quantum wires). In addition to its physical interest, this system has never been treated with the ET.
Optimal efficiencies of an isothermal endoreversible chemical engine
Authors: Ares de Parga-Regalado A M
Published: February 2023

In the context of finite-time thermodynamics, an instructive study of the thermodynamic and thermoeconomic optimization analysis of Novikov engine models is presented. The so-called objective functions of the maximum power, ecological and efficient power regimes of operation are introduced. The study addresses the optimization methodology to obtain the efficiencies that maximize the various functions. An isothermal chemical engine is used as an analogy to Novikov’s engine to demonstrate the physical and mathematical procedures. Didactically, new results are presented through expanding prior research.
Enhanced energy density at low operating field strength of laminated multicomponent polymer-based composites via regulation of electrical displacement
Authors: Chen Jie , Wang Zhen , Zhang Xiaoyong , Chen Weixing , Liu Yan-Jun , Wang Yifei
Published: February 2023

Dielectric polymer-based composites have demonstrated enormous promise in the applications of electrostatic film capacitors due to their exceptional insulating characteristics. However, the achievement of great energy-storage density (U
e) is always difficult in linear dielectric polymer-based composites for operation at weak field strength due to the low permittivity (ϵ
r) and electric displacement difference (D
max
− D
rem) values. Here, a tri-layered configuration of multicomponent polymeric films is proposed. The outer layers of the tri-layered composite are linear dielectric polymethyl methacrylate (PMMA), and the inner layer is a nonlinear polymer incorporating a low number of polydopamine-modified barium titanate particles (BT@PDA). An increased ϵ
r of 8.9@1 kHz is achieved in the designed composite featuring only 2 wt% BT@PDA fillers, equivalent to 234% of the PMMA (∼3.8@1 kHz) matrix. An improved U
e of 9.3 J cm−3 at 340 MV m−1 is endowed in the designed film, implying an enormous ∼343% increment of the energy storage compared to the benchmark biaxially oriented polypropylene (∼2.1 J cm−3 at 300 MV m−1). All these advantages present a practical strategy for supplying linear dielectric polymer-based composites with anticipative capacitive energy-storage properties for operation at weak field strengths.
Fractional calculus within the optical model used in nuclear and particle physics
Authors: Herrmann Richard
Published: February 2023

The optical model is a fundamental tool to describe scattering processes in nuclear physics. The basic input is an optical model potential, which describes the refraction and absorption processes more or less schematically. Of special interest is the form of the absorption potential. With increasing energy of the incident projectile, a derivation of this potential must take into account the observed energy dependent transition from surface to volume type. The classic approach has weaknesses in this regard. We will discuss these deficiencies and will propose an alternative method based on concepts developed within the framework of fractional calculus, which allows to describe a smooth transition from surface to volume absorption in an appropriate way.
A signal-filtering and feature-enhancement method based on ensemble local mean decomposition and adaptive morphological filtering
Authors: Zhou Hao , Yang Jianzhong , Guo Gaofeng , Xiang Hua , Chen Jihong
Published: February 2023

The bearing fault signals from the spindle motors of computer numerical control machines are complex and non-linear due to being coupled to multiple subsystems. The complexity of industrial signals, with increased industrial noise, and the difference in fault features in different life cycles and different individual signals bring great challenges for fault feature extraction. In this paper, a signal-filtering and feature-enhancement method based on an ensemble local mean decomposition and adaptive morphological filtering (ELMD-AMF) method is proposed. First, the original vibration signal of the bearing is reconstructed by ELMD to reducing interference from background noise. Next, an improved feature-enhancement process based on AMF is constructed, a particle swarm optimization with maximum-weighted spectral kurtosis as an optimization objective is used to adaptively construct the size of the structural element, and a morphology hat product operator one is adapted to extract the periodic impulse features. Finally, the effectiveness of the method is proved by using an actual three-phase induction motor matched with an NTN ceramic bearing and a FAG metal bearing, respectively. Further, compared with minimum entropy deconvolution and fast kurtogram methods, the result proves that the proposed method has better performance for both early-failure and late-failure scenarios under real-world engineering conditions.
Biophysical characterization of collimated and uncollimated fields in pencil beam scanning proton therapy
Authors: Nabha Racell , De Saint-Hubert Marijke , Marichal Joachim , Esser Johannes , Van Hoey Olivier , Bäumer Christian , Verbeek Nico , Struelens Lara , Sterpin Edmond , Tabury Kevin , Marek Lukas , Granja Carlos , Timmermann Beate , Vanhavere Filip
Published: February 2023

Objective. The lateral dose fall-off in proton pencil beam scanning (PBS) technique remains the preferred choice for sparing adjacent organs at risk as opposed to the distal edge due to the proton range uncertainties and potentially high relative biological effectiveness. However, because of the substantial spot size along with the scattering in the air and in the patient, the lateral penumbra in PBS can be degraded. Combining PBS with an aperture can result in a sharper dose fall-off, particularly for shallow targets. Approach. The aim of this work was to characterize the radiation fields produced by collimated and uncollimated 100 and 140 MeV proton beams, using Monte Carlo simulations and measurements with a MiniPIX-Timepix detector. The dose and the linear energy transfer (LET) were then coupled with published in silico biophysical models to elucidate the potential biological effects of collimated and uncollimated fields. Main results. Combining an aperture with PBS reduced the absorbed dose in the lateral fall-off and out-of-field by 60%. However, the results also showed that the absolute frequency-averaged LET (LETF) values increased by a maximum of 3.5 keV μm−1 in collimated relative to uncollimated fields, while the dose-averaged LET (LETD) increased by a maximum of 7 keV μm−1. Despite the higher LET values produced by collimated fields, the predicted DNA damage yields remained lower, owing to the large dose reduction. Significance. This work demonstrated the dosimetric advantages of combining an aperture with PBS coupled with lower DNA damage induction. A methodology for calculating dose in water derived from measurements with a silicon-based detector was also presented. This work is the first to demonstrate experimentally the increase in LET caused by combining PBS with aperture, and to assess the potential DNA damage which is the initial step in the cascade of events leading to the majority of radiation-induced biological effects.
Scatter correction for cone-beam CT via scatter kernel superposition-inspired convolutional neural network
Authors: Zhuo Xu , Lu Yuchen , Hua Yuexuan , Liu Hanxi , Zhang Yikun , Hao Shilei , Wan Lin , Xie Qingguo , Ji Xu , Chen Yang
Published: February 2023

Objective. X-ray scatter leads to signal bias and degrades the image quality in Computed Tomography imaging. Conventional real-time scatter estimation and correction methods include the scatter kernel superposition (SKS) methods, which approximate x-ray scatter field as a convolution of the scatter sources and scatter propagation kernels to reflect the spatial spreading of scatter x-ray photons. SKS methods are fast to implement but generally suffer from low accuracy due to the difficulties in determining the scatter kernels. Approach. To address such a problem, this work describes a new scatter estimation and correction method by combining the concept of SKS methods and convolutional neural network. Unlike conventional SKS methods which estimate the scatter amplitude and the scatter kernel based on the value of an individual pixel, the proposed method generates the scatter amplitude maps and the scatter width maps from projection images through a neural network, from which the final estimated scatter field is calculated based on a convolution process. Main Results. By incorporating physics in the network design, the proposed method requires fewer trainable parameters compared with another deep learning-based method (Deep Scatter Estimation). Both numerical simulations and physical experiments demonstrate that the proposed SKS-inspired convolutional neural network outperforms the conventional SKS method and other deep learning-based methods in both qualitative and quantitative aspects. Significance. The proposed method can effectively correct the scatter-related artifacts with a SKS-inspired convolutional neural network design.
Dependence of ion wake characteristics on experimental conditions
Authors: Banka Rahul , Vermillion Katrina , Matthews Lorin , Hyde Truell , Couëdel Lénaïc
Published: February 2023

Two-dimensional microparticle crystals can be formed in the sheath of a gas discharge plasma. Ions from the bulk plasma are accelerated in the sheath electric field, flowing past the grains to create a positive ion wake downstream from the grains. Interaction between the ion wake and neighboring grains creates additional coupling between oscillation modes and can trigger mode-coupling instability (MCI). In order to better understand MCIs, the interaction between dust grains and ion wakes must be understood; however, the relationship between the discharge parameters and ion wake characteristics is unknown. A molecular dynamics simulation of ion dynamics and dust charging is used to self-consistently determine the dust charge and ion wake characteristics for different synthetic experimental conditions. It is found that the ion wake is strongly dependent on the background gas pressure but not affected much by the discharge power.
Hydrogen in actinides: electronic and lattice properties
Authors: Havela Ladislav , Legut Dominik , Kolorenč Jindřich
Published: February 2023

Hydrides of actinides, their magnetic, electronic, transport, and thermodynamic properties are discussed within a general framework of H impact on bonding, characterized by volume expansion, affecting mainly the 5f states, and a charge transfer towards H, which influences mostly the 6d and 7s states. These general mechanisms have diverse impact on individual actinides, depending on the degree of localization of their 5f states. Hydrogenation of uranium yields UH2 and UH3, binary hydrides that are strongly magnetic due to the 5f band narrowing and reduction of the 5f-6d hybridization. Pu hydrides become magnetic as well, mainly as a result of the stabilization of the magnetic 5f
5 state and elimination of the admixture of the non-magnetic 5f
6 component. Ab-initio computational analyses, which for example suggest that the ferromagnetism of β-UH3 is rather intricate involving two non-collinear sublattices, are corroborated by spectroscopic studies of sputter-deposited thin films, yielding a clean surface and offering a variability of compositions. It is found that valence-band photoelectron spectra cannot be compared directly with the 5f n
ground-state density of states. Being affected by electron correlations in the excited final states, they rather reflect the atomic 5f n

−1 multiplets. Similar tendencies can be identified also in hydrides of binary and ternary intermetallic compounds. H absorption can be used as a tool for fine tuning of electronic structure around a quantum critical point. A new direction is represented by actinide polyhydrides with a potential for high-temperature superconductivity.
Synergistic effect of multi-parameters on NO density of a helium atmospheric pressure plasma jet in contact with skin
Authors: Wang LanPing , Wu Fan , Nie LanLan , Liu DaWei , Lu XinPei
Published: February 2023

Nitric oxide (NO) is a crucial molecule for living organisms, which acts as a messenger in most mammalian organs. Fortunately, plasma jet can generate an abundant amount of NO. In this paper, the NO generated by a helium plasma jet when it is interacting with pig skin is diagnosed using laser-induced fluorescence (LIF) method. The multi-parameters’ effect of the distance between the nozzle and the skin surface (distance d), the gas parameters (gas flow rate, O2 and H2O percentage) and the applied voltage parameters (the amplitude and frequency of the voltage) on the NO density is explored. The results show that the NO density increases and then decreases as the gas flow rate increases. The gas flow rate corresponding to the maximum NO density is positively correlated with the distance d. In the case of high gas flow rate or small distance d, premixing a small amount of O2 or H2O content lead to higher NO density. Higher voltage amplitude and frequency can increase NO density, but high voltage amplitude at high flow rate and small distance d lead to a decrease in NO density. The generation pathway of NO is mainly affected by N2(A), N, O2, O, OH, H and NO2, and the consumption pathway is closely related to the particles N, O, OH, O3 and HO2. Among them, N and O atoms participate in both generation and consumption. Therefore, the synergistic effect of multi-parameters, the emergence of different effects is closely related to the synergistic effect of these two particles.
The photocatalytic dye degradation of methylene blue (MB) by nanostructured ZnO under UV irradiation
Authors: Alzahrani Hassan A H , Almulaiky Yaaser Q , Alsaiari Abdulmohsen O
Published: February 2023

Photocatalytic degradation failure is a significant environmental pollution problem. Therefore, this article emphasizes the in-depth photocatalytic degradation of methylene blue (MB) by UV light irradiation using ZnO photocatalysts nanoparticles every 30 min of a time interval and examines the improvement in the irradiation period. The sol-gel co-precipitation route produces the photocatalyst ZnO nanoparticle to eliminate MB dye. The characterization studies of ZnO photocatalysts are explored by x-ray diffraction, scanning electron, and UV visible spectroscopic techniques. The XRD study elucidates a lesser crystallite size of the order 24.71 nm with a small microstrain, and dislocation density boosts the ZnO nanoparticle to act as dilapidation of 10 ppm of MB colourant. The SEM photographs of Zinc oxide nanoparticles reveal the nanospeck dimension of 32 nm. The EDX and Elemental mapping explore the composition of the ZnO photocatalyst. The syntheses of ZnO nanoparticles have low overpotential for HER (Hydrogen Evolution Reaction). A very low slope of 41.2 mV/dec represents the Volmer-Tafel mechanistic pathway for the HER process. Chronopotentiometry was conducted, and the amount of hydrogen collected during these experiments was 21 ml for the ZnO nanoparticles.
Electrical characterization of AgNPs-PVA nanocomposites thin film-based heterojunction diode
Authors: Khalil R , El-Desouky H , Sobhy R , El-Mansy M K
Published: February 2023

The purpose of this work is to study the results of electrical measurements carried out of nano metal-semiconductor heterojunctions based on Poly Vinyl Alcohol (PVA)to examine the possibilities of either an Ohmic contacts or rectifying behavior like a Schottky junction. The PVA doped silver nanoparticles (AgNPs-PVA)were confirmed and characterized by using x-ray Diffraction (XRD),Fourier-Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TG) and Differential Scanning Calorimeter (DSC). A thorough investigation of the predominant conduction mechanism, dielectric relaxation, and current-voltage behavior of a polyvinyl alcohol (PVA)–Silver nanoparticles (AgNPs) nanocomposite film has been presented. With two activation energies, Ag nanoparticles have been demonstrated to improve the conductivity and dielectric permittivity of films. In the sample, a non-Debye type asymmetric behavior has been found, which may be analyzed using a modified Cole-Cole model. The temperature dependence of the a.c. conductivity σ
ac and power law exponent s is reasonably interpreted by the Correlated Barrier Hopping (CBH) and Small Polaron Tunnelling (SPT) models at low and high frequency ranges, respectively. The junctions were created by spin coating and characterized of evaluated according to their I-V characteristics. Non-Ohmic electrical behavior was observed. The phenomenon supposed to be partly responsible for such nonlinearity is existence of thin barrier layer on the surface of dried polymer nanocomposites, through which charge carriers could pass by tunneling. This Schottky diode manufactured of an AgNPs-PVA nanocomposite was electrically characterized and investigated. However, deeper discussion will be necessary to illuminate all the circumstances leading to understand this behavior.
Numerical Simulation of Ultrathin CdTe Solar Cell by SCAPS-1D
Authors: Bhari Bibi Zulaika , Rahman Kazi Sajedur , Chelvanathan Puvaneswaran , Ibrahim Mohd Adib
Published: February 2023

Cadmium telluride (CdTe) has been recognized as one of the efficient and cost-effective thin film solar cell materials with a direct band energy of 1.5 eV. CdTe has long been a leading material in fabrication of solar cell due to its high optical absorption coefficient and ideal band gap. Despite the advantages of CdTe PV technology, CdTe is facing the challenge of Te scarcity. However, it is possible to decrease the CdTe thickness without much compromise in efficiency. Reducing the absorber layer thickness can lower the cost and usage of materials. It can assist to produce large scale CdTe solar cell module as Te is not an earth-abundant element. Numerical simulation of thin film solar cell is a crucial process for defining the possibility of anticipated solar structures, predicting the impact of differences in material characteristics and geometry on overall efficiency. In this research, Solar Cell Capacitance Simulator (SCAPS-1D) is applied to explore the impact of absorber layer thickness and carrier concentration in realizing ultrathin CdTe solar cell. It has been found that 500 nm thick absorber layer is sufficient for acceptable range of cell efficiency. Simulation results of 500 nm CdTe with the carrier concentration of 1.0 × 1014cm−3has an efficiency of 2.2%. For CdTe carrier concentration of 1.0 × 1017cm−3, the efficiency increases to 13.22% with open-circuit voltage of 0.988 V, a short-circuit current density of 16.19 mA/cm2and fill factor of 82.54%. The optimal numerical solar cell design suggests an approach to further enhance the efficiency of CdTe solar cells.
Design and Simulation of Lead-free Flexible Perovskite Solar cell Using SCAPS-1D.
Authors: Goje A A , Ludin N A , Mat Teridi M A , Syafiq U , Ibrahim M A , Nawab F , Syakirin A A
Published: February 2023

Despite perovskite solar cells’ rapidly increasing efficiency, industrializing and commercializing the device presents several challenges. Top among these is toxicity due to the material’s lead-based perovskite usage, which causes rapid degradation. Because of this challenge, researchers have recently become interested in lead-free perovskite materials. In this research, we investigate using the SCAPS simulation software to optimize a lead-free flexible solar cell. Lead (Pb), which belongs to group 14, can likely be replaced with bismuth (Bi), which belongs to group 15. In this study, the structure of the device is an n-i-p planar lead-free heterostructure flexible perovskite solar cell (FPSC) comprised of a Polyethylene Terephthalate/Indium Tin Oxide (PET/ITO) substrate; [6,6]-phenyl C61 butyric acid methyl ester (PCBM) Electron Transport Layer (ETL); methyl ammonium bismuth iodide (CH3NH3BiI3) as an absorber; Spiro-OMeTAD as a Hole Transport Layer (HTL); and silver (Ag) as the electrode. We optimised cell performance and efficiency with an absorber layer of 100 nm and an optimised temperature of 300 K. This absorber layer’s thickness and defect density were considered. The defect density of the FPSC is indirectly proportional to the device’s absorption coefficient (alpha). We obtained a power conversion efficiency (PCE) of 18.80%, a current density (JSC) of 35.59 mA/cm2, an open circuit voltage (VOC) of 0.633 V, and a fill factor (FF) of 83.43%. We also observed that the FF is inversely proportional to the thickness of the absorber layer of the FPSC.
Decarbonization of tropical city using digital twin technology: case study of Bertam city
Authors: Zaidi Nur Haziqah Mohamad , Haw Lim Chin
Published: February 2023

The urban population in Malaysia has increased to 77.7% in 2021, from 66% two decades ago, of which the current percentage shows Malaysia has more than 25 million city dwellers out of the 32.7 million total population. This statistic resulted in 80% of carbon emissions, roughly 200 million tCO2e, being produced by the urban cities in Malaysia. To balance out the high number of carbon emissions from urban settings, our government has aimed to reduce 33% of carbon by 2030, aligning with the COP commitment by Malaysia in 2021, and later aiming for carbon neutrality by 2050. Carbon neutrality can be achieved by using digital twin technology, which can virtually represent any physical system, including a whole city to its real-world counterpart. Bertam, a city in Pulau Pinang is used as a case study in this study. A baseline simulation has been made of the digital twin city, resulting in 253 kWh/m2 of total energy consumption in 2021, and 1.75 tonnes of carbon per capita. The recent applications of active and passive design strategies will be applied to the virtual city, to obtain its potential energy savings and carbon reduction data. At the end of the study, the digital twin technology will discover the city’s potential energy savings and carbon reduction after the optimization.
Optimum Configuration of Rainwater Harvesting System using CREO PARAMETRIC and ANSYS
Authors: Uddin MD Helal , Samsudin Nurul Asma , Amin Nowshad
Published: February 2023

The practice of rainwater harvesting (RWH) has been studied extensively in recent years, as it has the potential to alleviate the increasing stress on urban water distribution systems. An appropriate design and evaluation of an RWH system is necessary to improve system performance and the stability of the water supply. In this study, the design of the main components in the RWH system such as the gutter, water storage tank and water pump were varied based on the main material of the component and rainfall intensity. Each component was presented according to the results of design, stress and fluid analyses performed by Creo parametric 7.0 and ANSYS. The main outcome of this work is a computational design tool that can be used to improve the RWH system component’s performance considering a variety of factors. A design of a gutter made of polyvinyl chloride (PVC) with a yield strength of 50 MPa and a size of 5 inches was used. The rainwater will pass through a water pipe to a 500 L, High-Density Polyethylene (HDPE) water storage tank with a yield strength of 43 MPa. A 1 HP single-phase pump with a maximum flow rate of 196.2 L/min was used to generate a steady flow for household usage. The factor of safety of each component was obtained above 1.5 and was determined by the maximum Von Mises stress. Each component in the system has a different life span, however, the overall life span of the RWH system is estimated to be 20 years
Multi-stimuli-responsive and dynamic color tunable security ink for multilevel anticounterfeiting
Authors: Dubey Charu , Yadav Anjana , Baloni Diksha , Singh Sachin , Singh Anjani Kumar , Singh Sunil Kumar , Singh Akhilesh Kumar
Published: February 2023

Luminescent security features have been used for anticounterfeiting for a long time. However, constant effort is required to strengthen these security features to be ahead of counterfeiters. Here, we developed a multi-stimuli-responsive luminescent security ink containing Tb(ASA)3Phen, K2SiF6:Mn4+, and NaYF4:Yb3+/Er3+ luminescent materials in PVC gold medium. Tb(ASA)3Phen complex shows a broad excitation band in the UV region; upon UV light radiation it shows strong greenish emission of Tb3+ ions through the antenna effect. K2SiF6:Mn4+, on the other hand, has three excitation bands with maxima at 248, 354, and 454 nm which emit red light after excitation through these bands. NaYF4:Yb3+/Er3+ is used as an upconverting nanophosphor showing green emission under 976 nm laser excitation. Thus, the multi-stimuli-responsive luminescent security ink shows greenish, red, and green emissions under 367 nm, 450 nm, and 976 nm excitations, respectively. Furthermore, the distinct lifetimes of the activators in Tb(ASA)3Phen and K2SiF6:Mn4+, i.e. 0.1708 ms and 8.165 ms, respectively, under 380 nm excitation make this ink suitable for dynamic anticounterfeiting as well. The ink shows a change in the emission color with time delay, after the removal of the 380 nm excitation source, from greenish yellow (at 0 delays) to reddish color after a delay of 7.5 ms. These unique optical features along with excellent photo-, chemical- and environmental stability make this ink useful for advanced-level anticounterfeiting.
Boron vacancy-driven thermodynamic stabilization and improved mechanical properties of AlB2-type tantalum diborides as revealed by first-principles calculations
Authors: Ektarawong A , Johansson E , Pakornchote T , Bovornratanaraks T , Alling B
Published: February 2023

Thermodynamic stability as well as structural, electronic, and elastic properties of boron-deficient AlB2-type tantalum diborides, which is designated as

α
−

TaB

2
−
x

, due to the presence of vacancies at its boron sublattice are studied via first-principles calculations. The results reveal that

α
−

TaB

2
−
x

, where 0.167

≲
x
≲

0.25, is thermodynamically stable even at absolute zero. On the other hand, the shear and Young’s moduli as well as the hardness of stable

α
−

TaB

2
−
x

are predicted to be superior as compared to those of

α
−

TaB2. The changes in the relative stability and also the elastic properties of

α
−

TaB

2
−
x

with respect to those of

α
−

TaB2 can be explained by the competitive effect between the decrease in the number of electrons filling in the antibonding states of

α
−

TaB2 and the increase in the number of broken bonds around the vacancies, both induced by the increase in the concentration of boron vacancies. A good agreement between our calculated lattice parameters, elastic moduli and hardness of

α
−

TaB

2
−
x

and the experimentally measured data of as-synthesized AlB2-type tantalum diborides with the claimed composition of TaB

∼
2

, available in the literature, suggests that, instead of being a line compound with a stoichiometric composition of TaB2, AlB2-type tantalum diboride is readily boron-deficient, and its stable composition in equilibrium may be ranging at least from TaB

∼
1.833

to TaB

∼
1.75

. Furthermore, the substitution of vacancies for boron atoms in

α
−

TaB2 is responsible for destabilization of WB2-type tantalum diboride and orthorhombic Ta2B3, predicted in the previous theoretical studies to be thermodynamically stable in the Ta−B system, and it thus enables the interpretation of why the two compounds have never been realized in actual experiments.
Decomposing Hofmeister effects on amino acid residues with symmetry adapted perturbation theory
Authors: Gregory Kasimir P , Webber Grant B , Wanless Erica J , Page Alister J
Published: February 2023

Hofmeister effects, and more generally specific ion effects, are observed broadly in biological systems. However, there are many cases where the Hofmeister series might not be followed in complex biological systems, such as ion channels which can be highly specific to a particular ion. An understanding of how ions from the Hofmeister series interact with the proteinogenic amino acids will assist elucidation of why some binding interactions may be favoured over others. Using symmetry adapted perturbation theory (SAPT2 + 3), the interaction energies between a selection of anions and each amino acid have been investigated. The interaction strengths become more favourable in accordance with the Hofmeister series, and also with increasing polarity of the amino acids (with the exception of the negatively charged amino acid side chains). Furthermore, the interactions are generally most favourable when they simultaneously involve the side chain and both protic moieties of the backbone. The total interaction energy in these anion–amino acid complexes is also primarily determined by its electrostatic component, in a manner proportional to the þ (‘sho’) value of the anion.
Introduction: Carrie’s rebellion
Authors: Holt Thomas C.
Published: February 2023

Opening with the story of two ordinary black women’s defiance of Virginia’s law requiring segregated seating on public buses operating in the state, this chapter shows how the roots of the Movement to come was rooted in the distinctive life experiences and broad resistance of ordinary people, whose ability to defy racially discriminatory laws was enabled by broad social economic changes in the South during the years between the first and second world wars. The dramatic migration out of the rural South during the two world wars freed black southerners from the direct, personal control of landlord-employers who controlled almost every aspect of their daily lives and movements. By contrast, urban life provided a richer, more autonymous organizational life that enabled ordinary peoples’ resistance to the Jim Crow regime.
Freedom movements in the North
Authors: Holt Thomas C.
Published: February 2023

The conditions of possibility for the development of the civil rights movement had emerged first in northern cities during the First World War. The intensification of racial discrimination in employment, housing, and publics schools together with more resources and freedom to mobilize resistance encouraged and enabled the founding of permanent protest organizations. Although the public focus of many of these organizations shifted to supporting the southern movement during the 1950s and early 1960s, northern protests continued. After the passage of major civil rights legislation, national attention and resources shifted again to northern cities and to issues of education, housing, and employment that recent civil rights legislation had not adequately addressed. The agenda of the ill-fated Poor People’s Campaign of 1968 epitomized the difficulties of mobilizing a national response to those problems.
Introduction
Authors: Holloway Jonathan Scott
Published: February 2023

What does it mean to be American? What does it mean to be human? What does it mean to be a citizen? What does it mean to be civilized? The introduction establishes the chronological boundaries of the project. It points out that the African presence in what is now the United States, predates the establishment of the country by over 150 years, and it carries forward through the appearance of the Black Lives Matter movement. The African American experience is an evolving story that tells as much about what it means to be black in the United States as it does about the very meaning of the United States itself.
The paradoxes of post–civil rights America
Authors: Holloway Jonathan Scott
Published: February 2023

This chapter surveys the shifting political terrain from the late 1960s to the very recent past. The history of the Student Nonviolent Coordinating Committee (SNCC) demonstrates how the political landscape moved as that group transformed from embracing respectability politics to radical revolutionary ideologies. The federal government took notice and became committed to disrupting SNCC’s activism as well as that expressed by other groups like the Black Panthers. These groups espoused Black Power, but black women activists often criticized them for their failures to acknowledge black women’s work and black feminism, more generally. This chapter also moves from the political pragmatism of Lyndon B. Johnson to Barack Obama’s rise and subsequent election.
Suburbs: A Very Short Introduction
Authors: Abbott Carl
Published: February 2023

This book explores two centuries of suburban growth as integral to global urbanism. It argues that the future of an urbanizing world will be a suburban world and presents suburbs as places that are interesting and viable on their own terms rather than simply poor cousins of big cities. Examples come from every peopled continent, offering glimpses of suburbs from London to Lima, Sao Paolo to Singapore, Cairo to Chicago, and Dublin to Delhi. The approach is both historical and thematic. The book first traces the history of suburban development in England and North America to 1940 and then examines three different trajectories of suburbanization in more recent decades. The United States and other nations drawing on British planning traditions have built low-density suburbia characterized by owner-occupied housing, dependence on automobiles, planned New Towns, and a legacy of racial residential segregations. High-rise housing built by national governments dominated suburban rings in Eastern Europe and parts of Western Europe and East Asia. Where neither government nor private market has been able to meet demand, residents have acted themselves to create informal communities with self-built housing on cheap peripheral land, sometimes misleadingly called shantytowns. After this world tour, a chapter explores suburban rings as places of work, from early dispersed manufacturing and industrial suburbs to research and development suburbs in developed economies around the world. Another thematic chapter examines the negative and even dystopian reputation of suburbs and sprawl in literature, popular media, and science fiction.
130 PREDICTORS OF DRIVING STATUS IN OLDER IRISH ADULTS ATTENDING A GERIATRIC OUTPATIENT SERVICE
Authors: Moloney K , O'Flaherty N , Ahmad R , Laird E , Hughes C , McNulty H , Ward M , Strain J J , Molloy A M , Cunningham C , McCarroll K
Published: February 2023

Background

The main mode of transportation in Ireland remains travel by car. Transport mobility is important for older adults in accessing shops, healthcare, services, community and in maintaining relationships. Cessation of driving is associated with negative effects on mental health, loneliness and physical health. We aimed to explore factors associated with driving status in older adults living in an urban environment.

Methods

Study included adults aged greater than 65 years attending a geriatric outpatient service in an urban environment and recruited as part of the TUDA (Trinity Ulster, Department of Agriculture) study. We excluded those with a MMSE (Mini-Mental State Exam) less than 24 as we aimed to include only non-dementia patients. Physical frailty was measured with the Timed Up and Go (TUG) and depression with the Center for Epidemiological Studies Depression scale (CES-D). Factors associated with driving status were explored in multinomial regression models.

Results

1978 adults, mean age 77.7 ± 7.1 years, 76.0% were female. 35.5% were current drivers but this differed by age category 45.9% (65–75 years), 25% (75–85 years) and 12.5% (85+ years). 28.1% were past drivers. Positive independent predictors of current driving were younger age (P < 0.001), male gender (P < 0.001), married status (P = 0.01), higher socioeconomic status (P < 0.0001) while negative predictors included physical frailty (TUG, P < 0.001), visual impairment (P = 0.01), stroke (P < 0.001), depression (P < 0.001) and self reported loneliness (P = 0.01).

Conclusion

One third of patients attending a geriatric outpatients in an urban environment were currently driving which is much lower than in the general older Irish population. However, our study included frail adults living in more deprived socioeconomic areas and had a high proportion of females who had never learned to drive. Furthermore, access to urban public transport may be a factor. Non-drivers were more likely to have depression and report loneliness independent of other factors highlighting its negative impact.
257 POSITIVE HEALTH AND AGING FOR OLDER IRISH TRAVELLERS AND OLDER PEOPLE WHO HAVE EXPERIENCED HOMELESSNESS: LIFE-COURSE MEANINGS AND DETERMINANTS
Authors: Walsh K , Carroll C , Scharf T , O’Donovan D
Published: February 2023

Background

The position of marginalized groups of older people remains neglected in positive health and aging (PHA) agendas, whether they concern healthy, active or positive aging. Questions exist around the meaning of such constructs, and the factors that enable disadvantaged populations to achieve equitable later-life experiences. In focusing on two such groups, this study investigates the constituent dimensions of PHA for older Irish Travellers and older people who have experienced homelessness, and the role of life-course and structural determinants in constructing PHA trajectories for these groups.

Methods

The study involves a multi-method qualitative, participatory voice-led methodology, but the analysis draws primarily on 49 in-depth life-course interviews with the populations.

Results

In addition to five interconnected dimensions of PHA, four determinants related to life-course experiences and structural factors are identified: social relations; material and accommodation circumstances; formal supports and systems; and critical transitions and resilience.

Conclusion

While illustrating the validity of PHA agendas for these groups when understood through their lived experiences, the findings highlight the significant deprivations and risks to rights that must be accounted for to secure meaningful gains in PHA for the groups.
32 SIMULATION-BASED EDUCATION FOR ACUTE STROKE
Authors: Crowley P , Saramago I , Cannon R , McGrath K
Published: February 2023

Background

Acute stroke requires efficient multi-disciplinary collaboration to deliver time-sensitive treatment in a prompt and effective manner. The European Stroke Organization (ESO) recommends simulation-based education (SBE) for stroke care. Studies have shown SBE improves door-to-needle times, which predict better patient outcomes.

SimStars was a competition, run by the National Doctors Training and Planning leads for the South-SouthWest Hospitals Group, to develop in-situ SBE scenarios.

We developed a SBE program for acute stroke in an Irish teaching hospital.

Methods

Medical doctors and nursing staff are included in the SBE scenario as candidates/target learners. Patients are played by role-players. Anonymised data and neuroimaging from real patients is utilized to maximize fidelity to real life. Other participants, such as paramedics, can be included to facilitate scenarios as required.

Candidates are briefed before each scenario. Clear learning objectives are set. All participants are provided with a script outlining their roles. Candidates are appraised using standard evaluation forms. A de-brief is undertaken to reinforce learning objectives.

Results

We qualified for the final of SimStars by establishing a SBE program for acute stroke, including a video of a simulated scenario that can be utilized for demonstration purposes. 100% of candidates who have participated in the SBE program so far have stated that it made a valuable contribution to their learning in the field of stroke care.

Conclusion

Stroke has been described as an exemplar of how SBE may benefit training along an entire clinical pathway. Scenarios can be adapted to cover an endless variety of stroke-related situations. SBE has been shown to improve hyper-acute clinical pathway performance and outcomes.
73 THE NEW CHRONIC DISEASE MANAGEMENT PROGRAMME FOR GENERAL PRACTITIONERS: MAKING THE CASE FOR ITS REVISION TO INCLUDE DEMENTIA
Authors: Pierce M , Cahill S
Published: February 2023

Background

A significant component of the new contract for general practitioners is the chronic disease management programme (CDMP for GPs). Although dementia can be framed as a chronic disease, it was not included in this programme. Its exclusion raises a number of questions including: Should dementia be framed as a chronic disease? Is it feasible to include dementia in a future revised CDMP for GPs? What are the likely benefits and potential risks?

Methods

This presentation focuses on two elements of a larger mixed-methods study, namely: (i) in-depth analysis of the CDMP for GPs, involving a review of the programme’s three main components to test the feasibility of extending it to incorporate dementia; and (ii) qualitative content analysis of data from semi-structured interviews with 12 stakeholders whose expertise is in dementia, chronic disease or both. Both elements were informed by a literature review.

Results

No consensus was found about whether dementia should be framed as a chronic disease. Results showed that it is feasible to extend the annual preventative programme of the CDMP for GPs to include additional modifiable dementia risk factors. While opportunistic case finding for identifying undiagnosed dementia cannot be recommended, a tool is available that would enable GPs identify people with dementia for enrolment on the structured treatment programme. Expected benefits from including dementia in the CDMP for GPs include integrated care pathways, better GP access and record-keeping and greater emphasis on primary and secondary prevention. Expected risks include excessive costs, caregiver burden, increased GP workload and sub-optimal care due to lack of specialist dementia training.

Conclusion

There is a compelling case to support dementia risk reduction in the CDMP for GPs. However, the programme’s current emphasis on self-management and rigidly planned visits could prove problematic for people with dementia and would need substantial revision.
100 SCREENING FOR SLEEP DISTURBANCE AS PART OF THE COMPREHENSIVE GERIATRIC ASSESSMENT
Authors: Mc Carthy C E , O'Malley K , Geoghegan J , Mannion E , Costello M , Murphy R , Reddin C , Waters R , O'Donnell M , Robinson S , Canavan M
Published: February 2023

Background

Sleep disturbance is common in the older patient, and has been associated with many common comorbidities, falls, impaired quality of life, and mortality. Sleep disturbance screening and management are important elements of the comprehensive geriatric assessment (CGA). There are few sleep disturbance assessment tools, however, that have been validated for use in older patients, or in those with cognitive impairment. We sought to review the assessment and management of sleep disturbance within a regional integrated care outreach programme (ICOP), where the RU-SATED tool had been used.

Methods

From March–June’21 the notes of 30 consecutive patients, presenting to ICOP with cognitive complaints, were reviewed. Demographic and sleep disturbance data were collected, in addition to whether advice, treatment or further assessment for sleep disturbance was documented. Feedback from staff on the utility of the RU-SATED tool was also sought.

Results

Of those reviewed, the mean age was 80.3 (SD = 7.8), and the mean Montreal Cognitive Assessment score (MOCA) was 17.7 (SD = 5.9). Where data was available, the mean RU-SATED score was 7.6 (SD = 1.9), and 42% were frail (n = 11). The most commonly endorsed sleep symptom was sleep onset latency/sleep maintenance issues (n = 16). RU-SATED score did not significantly predict age, MOCA or frailty (p > 0.1 for all). Advice, treatment or further assessment of sleep disturbance was offered to 23% of patients (n = 7), and this was not predicted by overall RU-SATED score or by individual question responses (p > 0.1 for all). Staff also stated that they found elements of the tool difficult to explain and interpret.

Conclusion

Although the numbers are small, we have not found the RU-SATED tool to be helpful in guiding the management of sleep disturbance in our cohort. A more practical CGA tool is currently in development by the ICOP service.