bluuebunny/crossref_metadata_2025 huggingface dataset:
New rule and growth model for the synthesis method of gold nanorods with binary surfactant CTAB and NaOL
Authors: Wei Ming-Zhang , Deng Tian-Song , Zhang Qi , Chen Xi , Cheng Zhiqun , Li Shiqi , Gu Yi-Jie
Published: August 2022

The roles of CTAB and Ag+ have been discovered and given us a deeper understanding of the seed-mediated method in the gold nanorods synthesis. Former work used binary surfactants CTAB + NaOL (sodium oleate) to greatly improve the dimensional tunability and monodispersity of gold nanorods. However, they only used a few of the concentration combinations of the binary surfactants, and the influence of NaOL under this method has not been systematically studied. In this work, we carried out systematic experiments under the variation of NaOL and used transmission electron microscopy and UV–vis-near-infrared spectroscopy to monitor the growth process of the gold nanorods. The results showed that the NaOL contributed to the symmetry breaking process. We discovered the ideal ranges of NaOL concentration under different concentrations of CTAB (10–40 mM). Lower concentrations of NaOL produced many impurities, such as Au spheres, while higher concentrations of NaOL led to the decrease of monodispersity of the obtained gold nanorods. A growth model based on the balance of diffusion/reduction of the growth solution has been proposed in order to explain the formation of the gold nanorods.
Faraday-effect polarimetry for current profile measurement in the tokamak plasma edge
Authors: Chen J. , Brower D. L. , Benedett T.
Published: August 2022

Toroidal current profile measurements in the tokamak plasma edge are critical for fusion plasma physics research and model validation. A three-wave Faraday-effect polarimeter-interferometer with a sub-centimeter spatial resolution is proposed on the DIII-D tokamak to determine the edge current profile via Abel inversion. By using probe beams with 316 µm wavelength, a low-field-side, vertical-view, single-pass optical layout covering the plasma edge region (R = 2.15–2.27 m) is assessed. Measurements with no greater than 0.1° polarimetric systematic uncertainty, no greater than 0.01° polarimetric root-mean-square noise (1 kHz bandwidth), and a 0.8 cm radial chord spacing are considered feasible based on the achieved performance of existing systems using similar wavelengths on fusion devices. Synthetic diagnostic calculations taking various factors into account, such as diagnostic uncertainty and quality of magnetic flux surfaces, find that the edge current profile can be determined with up to 0.12 MA/m2 uncertainty, or about 10% of the peak current density in the pedestal of an investigated high-confinement plasma.
Self-organized magnetic equilibria in tokamak plasmas with very low edge safety factor
Authors: Hurst N. C. , Chapman B. E. , Almagri A. F. , Cornille B. S. , Kubala S. Z. , McCollam K. J. , Sarff J. S. , Sovinec C. R. , Anderson J. K. , Den Hartog D. J. , Forest C. B. , Pandya M. D. , Solsrud W. S.
Published: August 2022

Tokamak plasmas often exhibit self-organizing behavior in which internal modes shape the toroidal current density profile, a common example being the sawtooth instability. However, such behavior has not been studied in detail for edge safety factor below 2 due to disruptive kink instabilities that typically prevent operation in this regime. Now, steady tokamak plasmas with an edge safety factor down to 0.8 have been created in the Madison Symmetric Torus, where disruptions are prevented due to a thick, conductive wall and a feedback power supply that sustains the plasma current. Internal measurements and nonlinear magnetohydrodynamic modeling reveal a family of safety factor profiles with a central value clamped near unity as the edge safety factor decreases, indicating current profile broadening through a relaxation process. As the safety factor decreases, the magnetic fluctuations become irregular, and the electron energy confinement time decreases.
Density of states below the first sound mode in 3D glasses
Authors: Wang Lijin , Fu Licun , Nie Yunhuan
Published: August 2022

Glasses feature universally low-frequency excess vibrational modes beyond Debye prediction, which could help rationalize, e.g., the glasses’ unusual temperature dependence of thermal properties compared to crystalline solids. The way the density of states of these low-frequency excess modes D(ω) depends on the frequency ω has been debated for decades. Recent simulation studies of 3D glasses suggest that D(ω) scales universally with ω4 in a low-frequency regime below the first sound mode. However, no simulation study has ever probed as low frequencies as possible to test directly whether this quartic law could work all the way to extremely low frequencies. Here, we calculated D(ω) below the first sound mode in 3D glasses over a wide range of frequencies. We find D(ω) scales with ωβ with β < 4 at very low frequencies examined, while the ω4 law works only in a limited intermediate-frequency regime in some glasses. Moreover, our further analysis suggests our observation does not depend on glass models or glass stabilities examined. The ω4 law of D(ω) below the first sound mode is dominant in current simulation studies of 3D glasses, and our direct observation of the breakdown of the quartic law at very low frequencies thus leaves an open but important question that may attract more future numerical and theoretical studies.
Cross-flow linear instability in compressible boundary layers over a flat plate
Authors: Liu Zhiyong
Published: August 2022

The linear instability of compressible boundary layers over a flat plate in the presence of parameterized crossflow has been investigated by means of linear stability theory. A family of boundary layer with crossflow is obtained as the base flow from the compressible Falkner–Skan–Cooke (FSC) flow model. Two factors, that is, the local swept angle and the pressure-gradient parameter, are designed to create the crossflow with different directions and magnitudes, which further results in the variation of the cross-flow instability. Modal properties related to the cross-flow instability are emphasized. The association between the cross-flow mode and the Mack's mode is clarified by extending the base flow from two dimension to three dimension. The cross-flow instability is discovered to be integrated with the slow-mode instability, that is, the instability related to the Tollmien–Schlichting (T–S) mode or the first mode, and it can hardly be distinguished as an individual mode in most cases. The effects of Mach number, pressure gradient, local sweep, and wall temperature are studied. The behaviors of the cross-flow instability under such effects resemble those of the slow-mode instability in the two-dimensional boundary layers. It is found that the unstable modes in the three-dimensional boundary layers are mainly affected by the streamwise pressure gradient and the crossflow per se. Specifically, the first mode is much more sensitive to the crossflow than the second mode. As a result, more marked variations are commonly observed for the first mode in the boundary layers with crossflow.
Comparative studies of hydrodynamic force models for flexible pipe in an oscillatory flow
Authors: Ren Haojie , Fu Shixiao , Zhang Mengmeng , Xu Yuwang , Song Bin , Sun Tongxiao
Published: August 2022

The objective of this comparison study is to verify and clarify whether the energy competitive force model has significant benefits in eliminating the influence of certain factors on the hydrodynamic coefficient. The typical cases with the smaller Keulegan–Carpenter (KC) number (KC = 31) and larger KC number (KC = 178) under the maximum reduced velocity of 6.5 with the prominent VIV responses are selected for analysis. The characteristics of the ortex-induced vibration (VIV) response, the hydrodynamic force, and the corresponding spatiotemporal coefficients in typical cases are revealed, compared, and discussed. The results suggest that the energy competition force model cannot avoid spatial-temporal distribution characteristics of the hydrodynamic coefficients. Drag and excitation coefficients with energy roles under Sarpkaya's and energy competitive force models are affected by the VIV response and wake effects in an oscillatory flow. The larger coefficients are witnessed under the smaller KC number. When the KC number increases from 31 to 178, the mean drag coefficients decrease from 2.25 to 1.73, and the mean excitation coefficients in in-line (IL) and cross-flow (CF) directions decrease from 1.42 and 1.44 to 0.60 and 0.81, respectively, under the energy competition force model. Changes in wake effects under a larger KC number lead to distinctive differences in drag and excitation coefficients during the acceleration and deceleration phases. Through a quantitative comparative analysis, the current identified drag and excitation coefficients under the energy competition force model can obtain a more accurate prediction result. The present work shows that there exists the blindness in the selection of coefficients within the framework of the energy competition force model.
Organic side streams (bioproducts) as substrate for black soldier fly (
Authors: Alagappan Shanmugam , Rowland Duncan , Barwell Rob , Cozzolino Daniel , Mikkelsen Deirdre , Olarte Mantilla Sandra M. , James Peter , Yarger Olympia , Hoffman Louwrens
Published: August 2022

The growing world population accompanied by urbanisation and improved economies has resulted in an increased demand for diets rich in animal proteins. The rearing of livestock by existing practices is also becoming increasingly difficult due to changing environmental conditions. The use of black soldier fly larvae (BSFL) grown on organic side streams (bioproducts) as feed for animals presents a sustainable alternative to conventional feed ingredients. The nutritional and compositional profile of BSFL reared on organic side streams and their potential to be used as animal feed has been extensively explored. However, little information is available on the chemical safety of BSFL reared on organic side streams. This review addresses the chemical safety hazards of BSFL reared on substrates spiked with different chemical contaminants, including heavy metals, mycotoxins, pesticides, and pharmaceuticals. BSFL were observed to excrete mycotoxins and were able to reduce the concentration of pesticides and pharmaceutical compounds in the substrate. Certain heavy metals were found to be accumulated in BSFL when grown on spiked substrate. Initial studies have also indicated that the growth parameters and composition of BSFL are not altered by the presence of microplastics and organic pollutants in the substrate. Information about these feed-safety issues will assist in developing regulatory frameworks and appropriate processing methods to mitigate these hazards, thereby providing a framework of risks for the commercialisation of BSFL destined for animal feed.
Eps15/Pan1p is a master regulator of the late stages of the endocytic pathway
Authors: Enshoji Mariko , Miyano Yoshiko , Yoshida Nao , Nagano Makoto , Watanabe Minami , Kunihiro Mayumi , Siekhaus Daria E. , Toshima Junko Y. , Toshima Jiro
Published: August 2022

Endocytosis is a multistep process involving the sequential recruitment and action of numerous proteins. This process can be divided into two phases: an early phase, in which sites of endocytosis are formed, and a late phase in which clathrin-coated vesicles are formed and internalized into the cytosol, but how these phases link to each other remains unclear. In this study, we demonstrate that anchoring the yeast Eps15-like protein Pan1p to the peroxisome triggers most of the events occurring during the late phase at the peroxisome. At this ectopic location, Pan1p recruits most proteins that function in the late phases—including actin nucleation promoting factors—and then initiates actin polymerization. Pan1p also recruited Prk1 kinase and actin depolymerizing factors, thereby triggering disassembly immediately after actin assembly and inducing dissociation of endocytic proteins from the peroxisome. These observations suggest that Pan1p is a key regulator for initiating, processing, and completing the late phase of endocytosis.
One-step synthesis of C quantum dots/C doped g-C3N4 photocatalysts for visible-light-driven H2 production from water splitting
Authors: Cao Jian , Jin Xiaoli , Ma Zhaoyu , Wang Huiqing , Xu Yixue , Guo Yuwei , Xie Haiquan , Zhang Junying
Published: August 2022

Graphitic carbon nitride (g-C3N4) is gaining more and more attentions as a promising metal-free photocatalyst for H2 production. Nevertheless, from the perspective of practical applications, the photocatalytic performance over g-C3N4 in visible-light region needs a further improvement. In this work, C doping and C quantum dots (QDs) are co-integrated in g-C3N4 by a one-step thermal polymerization method to obtain an advanced C QDs/C doped g-C3N4 photocatalyst. The synergistic effects of C doping and C QDs modification promote the photocatalytic activity of g-C3N4 significantly. The optimal C QDs/C doped g-C3N4 exhibits a significant improvement on visible-light-driven photocatalytic hydrogen production (205 μmol g−1 h−1) with an apparent quantum yield (AQE) at 420 nm reaching 1.24%, which is approximately nine-fold enhancement than that of pristine g-C3N4. The increased photocatalytic activity mainly benefits from the enhanced visible light absorption and carrier separation efficiency. This study may open a new perspective for the design and fabrication of C-modified g-C3N4 for photocatalytic hydrogen production.
Enhanced shift current bulk photovoltaic effect in ferroelectric Rashba semiconductor α-GeTe: ab initio study from three- to two-dimensional van der Waals layered structures
Authors: Tiwari Rajender Prasad
Published: August 2022

The ferroelectric Rashba semiconductors (FERSCs) are endowed with a unique combination of ferroelectricity and the spin degree of freedom, resulting in a long carrier lifetime and impressive bulk photovoltaic (BPV) efficiency that reached 25% in organometal halide perovskites. The BPV efficiency can be further improved by using low-dimensional ferroelectrics however, it is inhibited by the ferroelectric instability in low-dimensional perovskites and toxicity along with phase instability of the lead-halide perovskites. To address these challenges, the α-GeTe could be of great importance which is the simplest known lead-free FERSC with an intrinsic layered structure. Therefore, in this work, we investigate the BPV properties of three- to two-dimensional van der Waals structures of α-GeTe by calculating the shift current (SHC). We predict that the mono (1.56 Å) and bi-layers (5.44–6.14 Å) α-GeTe with the buckled honeycomb structure are dynamically stable and possess the characteristic features of the bulk up to the nanoscale limit. The SHC of ∼70 μA V−2 is calculated in bulk α-GeTe which is 20 times larger than that obtained in organometal halides in the visible light. The SHC increases with decreasing the number of layers, reaching a maximum amplitude of ∼300 μA V−2 at 2.67 eV in the monolayer which is more than double that obtained in monolayer GeS. We find that the SHC in monolayer α-GeTe can be further enhanced and redshifted by applying a compressive strain; which is correlated with the strong absorption of the xx-polarized light, stimulated by the more delocalized p
x

/y
orbital character of the density of states. Furthermore, in the bilayer structures, the magnitude of the SHC is sensitive to the layers’ stacking arrangement and a maximum SHC (∼250 μA V−2) can be achieved with an AB-type stacking arrangement. Combining these results with the benefits of being environmental-friendly material makes α-GeTe a good candidate for next-generation solar cells application.
Electrochemical epitaxial PbTe nanowires photodetector for NIR response
Authors: Guo Zhongmin , Zhang Zhisheng , Yan Ruiyang , Feng Shuanglong
Published: August 2022

Lead telluride nanowires deposited by electrochemical atomic layers have broad application prospects in the field of photodetectors. In this work, using the method of electrochemical atomic layer deposition, we obtained different morphologies of lead telluride materials by controlling the deposition parameters, such as deposition time, temperature, and potential, and characterized them using SEM, TEM, XPS, and other techniques. A lead telluride nanowire detector with good performance was prepared. The photoresponsivity of the detector is 102 mA W−1, the detectivity is 2.1 × 108 Jones, and the response time and recovery time are 0.52 s and 0.54 s respectively at 2.7 μm wavelength laser irradiation.
SPECT imaging of 226Ac as a theranostic isotope for 225Ac radiopharmaceutical development
Authors: Koniar Helena , Rodríguez-Rodríguez Cristina , Radchenko Valery , Yang Hua , Kunz Peter , Rahmim Arman , Uribe Carlos , Schaffer Paul
Published: August 2022

Objective. The development of alpha-emitting radiopharmaceuticals using 225Ac (t
½ = 9.92 d) benefits from the quantitative determination of its biodistribution and is not always easy to directly measure. An element-equivalent matched-pair would allow for more accurate biodistribution and dosimetry estimates. 226Ac (t
½ = 29.4 h) is a candidate isotope for in vivo imaging of preclinical 225Ac radiopharmaceuticals, given its 158 keV and 230 keV gamma emissions making it suitable for quantitative SPECT imaging. This work aimed to conduct a performance assessment for 226Ac imaging and presents the first-ever 226Ac SPECT images. Approach. To establish imaging performance with regards to contrast and noise, image quality phantoms were scanned using a microSPECT/CT system. To assess the resolution, a hot rod phantom with cylindrical rods with diameters between 0.85 and 1.70 mm was additionally imaged. Two collimators were evaluated: a high-energy ultra-high resolution (HEUHR) collimator and an extra ultra-high sensitivity (UHS) collimator. Images were reconstructed from two distinct photopeaks at 158 keV and 230 keV. Main results. The HEUHR SPECT image measurements of high activity concentration regions were consistent with values determined independently via gamma spectroscopy, within 9% error. The lower energy 158 keV photopeak images demonstrated slightly better contrast recovery. In the resolution phantom, the UHS collimator only resolved rods ≥1.30 mm and ≥1.50 mm for the 158 keV and 230 keV photopeaks, respectively, while the HEUHR collimator clearly resolved all rods, with resolution <0.85 mm. Significance. Overall, the feasibility of preclinical imaging with 226Ac was demonstrated with quantitative SPECT imaging achieved for both its 158 keV and 230 keV photopeaks. The HEUHR collimator is recommended for imaging 226Ac activity distributions in small animals due to its resolution <0.85 mm. Future work will explore the feasibility of using 226Ac both as an element-equivalent isotope for 225Ac radiopharmaceuticals, or as a standalone therapeutic isotope.
Absolute keV x-ray yield and conversion efficiency in over dense Si sub-petawatt laser plasma
Authors: Ryazantsev Sergey N , Martynenko Artem S , Sedov Maksim V , Skobelev Igor Yu , Mishchenko Mikhail D , Lavrinenko Yaroslav S , Baird Christopher D , Booth Nicola , Durey Phil , Döhl Leonard N K , Farley Damon , Lancaster Kathryn L , McKenna Paul , Murphy Christopher D , Pikuz Tatiana A , Spindloe Christopher , Woolsey Nigel , Pikuz Sergey A
Published: August 2022

Laser-produced plasmas are bright, short sources of x-rays commonly used for time-resolved imaging and spectroscopy. Their usage implies accurate knowledge of laser-to-x-ray conversion efficiency (CE), spectrum, photon yield and angular distribution. Here, we report on soft x-ray emission in the direction close to the target normal from a thin Si foil irradiated by a sub-PW picosecond laser pulse. These absolute measurements cover a continuous and broad spectral range that extends from 4.75 to 7.3 Å (1.7–2.6 keV). The x-ray spectrum consists of spectral line transitions from highly charged ions and broadband emission with contributions from recombination and free-free processes that occur when electrons decelerate in plasma electromagnetic fields. Angular distribution of the emission was investigated via particle-in-cell simulations, which allowed to estimate the yield into the full solid angle. We find that experimental and simulation estimations of laser to free-free emission CE are in good agreement.
Efficient vibrational excitation of molecular nitrogen in low-pressure plasma with ultralow electron temperature
Authors: Yamazaki Masahiro , Sasaki Koichi
Published: August 2022

We investigated the vibrational temperature of molecular nitrogen in the downstream of helicon-wave excited helium and argon-based plasmas. It was confirmed by optical emission spectroscopy that the major part of the helium plasma was at a recombining state and it had an ultralow electron temperature of approximately 0.1 eV. In spite of the ultralow electron temperature, the vibrational temperature of molecular nitrogen, which was added into the helium plasma, was higher than that in the argon-based plasma at an ionizing state with an electron temperature of 1.7 eV. According to the relationship between the rate coefficient of electron impact vibrational excitation and the electron temperature, the higher vibrational temperature in the helium plasma is not attributable to the more efficient vibrational excitation. Therefore, the higher vibrational temperature is owing to the less efficient destruction of vibrational excited states in the helium plasma with the ultralow electron temperature.
Interaction between microwave and dielectric surface discharge in vacuum and low-pressure gas
Authors: Zhao Pengcheng , Wang Rui , Guo Lixin
Published: August 2022

The interaction between high-power microwave and dielectric surface discharge in vacuum and low-pressure gas is investigated by using an electromagnetic particle-in-cell–Monte Carlo collision model. Maxwell equations are solved by the finite-difference time-domain method combined with the boundary condition between the total and scattered field. The simulation results show that the transmission power loss is small and mainly attributed to the absorption of surface discharge, when the secondary electron multipactor reaches a steady state in vacuum. The simulated value of transmission power loss in vacuum is in good agreement with the experimental data. At a low pressure, the multipactor is the main source of electrons in the initial stage of discharge. After the multipactor reaches a steady state, the ionization leads to a significant increase in the number density of plasma near the dielectric surface. The absorbed power of plasma is greater than the reflected power in the initial stage of discharge, but with the increase of time, the latter becomes larger and even close to the power of incident wave. As the pressure increases, the transmission power decays faster due to the increase of ionization rate. When the microwave field near the dielectric surface decays significantly at a low pressure, the steady state of multipactor disappears, and the peak of plasma number density is near the surface, but not closest to the surface.
Reversible critical current performance of FeSe0.5Te0.5 coated conductor tapes under uniaxial tensile strain
Authors: Liu Xiao , Wei Shaoqing , Shi Yi , Liu Fang , Zhou Chao , Li Qianbo , Li Yijie , Liu Linfei , Shi Zhixiang , Ren Li , Xu Ying , Duan Pu , Yang Zhixing , Ge Junyi , Qi Yanpeng , Song Yuntao , Liu HuaJun , Zhang Zhan , Qin Jinggang
Published: August 2022

FeSe0.5Te0.5 coated conductor as a kind of 11-type iron-based superconductor is currently attracting much attention. Recently, the bare FeSe0.5Te0.5 coated conductor tapes were developed by Shanghai Jiao Tong University and verified their superconductivity. For the future application, the FeSe0.5Te0.5 tapes should be subjected to the high electromagnetic forces and stress–strain. In this study, the authors encapsulated the bare FeSe0.5Te0.5 coated conductor tapes with copper layers to enhance the mechanical performance. The reversible critical current performance of the bare and the copper encapsulated FeSe0.5Te0.5 tapes under uniaxial tensile strain was tested. The critical currents of two kinds of tapes were measured over a wide range of applied uniaxial tensile strain by the U-shaped bending spring, respectively. The results show the critical performance of the bare FeSe0.5Te0.5 tapes decreases linearly with respect to tensile strain. The copper encapsulated FeSe0.5Te0.5 tapes have better performance than the bare tapes, with an irreversible tensile strain limit of 0.15%. In addition, the actual irreversible tensile strain limit of the copper encapsulated FeSe0.5Te0.5 tapes reaches 0.29% after considering the influence of the cooling process.
The Stellar Abundances and Galactic Evolution Survey: Photonic Passbands and Extinction Coefficients for the u and v Bands
Authors: Tan Ke-Feng , Zhao Gang , Fan Zhou , Wang Wei , Yuan Hai-Bo , Zheng Jie , Li Chun , Song Nan , Zhao Jing-Kun
Published: August 2022

The Stellar Abundances and Galactic Evolution Survey (SAGES) is a multi-band photometric survey focused on estimation of stellar atmospheric parameters and interstellar extinction. In this paper we have derived photonic passbands for the intermediate-band u and v filters of the SAGES photometric system. The derived photonic passbands have been compared with those of the u and v filters of the Strömgren and SkyMapper systems. Synthetic photometry based on the derived photonic passbands could reproduce the observations very well. We have also derived observed, model-free extinction coefficients for the SAGES u and v bands (as well as the Pan-STARRS grizy bands) using the “standard pair” method. The derived reddening coefficients have been compared with those predicted by the extinction laws. Variations of reddening coefficients with effective temperatures and color excesses of B–V given by Schlegel et al. (E(B−V)SFD) have been investigated. No obvious trends or significant variations with effective temperatures have been found, but reddening coefficients for all the colors exhibit declining trends with increasing E(B−V)SFD, with typical relative variations of twenty-some percent from E(B − V)SFD ∼ 0 to 1.
Do water savings persist? Using survival models to plan for long-term responses to extreme drought
Authors: Bolorinos Jose , Rajagopal Ram , Ajami Newsha K
Published: August 2022

Water utilities must maintain reliable service in a world where climate shocks and other socio-economic and health stressors are likely to disrupt water availability and demand more frequently. Understanding short- and long-term customer responses to these salient events is critical for infrastructure planning and capital investment. Although the short-term demand impacts of extreme droughts and related policy measures have been studied extensively, less is known about how these impacts persist—especially when driven by public awareness, media coverage, or other external drivers. Here, we introduce a novel approach combining survival models and change detection to assess water demand conservation ‘survival’ and rebound, using this method to analyze residential water demand in Costa Mesa, California after the state’s record-breaking 2012–2016 drought. We find that, of 54% of customers with detected savings in 2014–2015, just 25% rebounded to prior consumption levels after 5 years, implying mean conservation survival of 8 years. Survival was greater in young and politically progressive neighborhoods, smaller in residences with occupancy changes, and not significantly associated with water-efficiency rebates. Comparing the 2012–2016 drought to California’s milder 2007–2009 drought shows no evidence that drought severity associated with water savings persistence. This study presents an innovative approach to measure impacts of various stressors and their long-term water demand impacts. Our method enables utilities to more accurately discern structural changes in water demand, better informing strategic planning for short- and long-term water reliability and security.
Influences of stratospheric intrusions to high summer surface ozone over a heavily industrialized region in northern China
Authors: Zhang Yujing , Li Jie , Yang Wenyi , Du Huiyun , Tang Xiao , Ye Qian , Wang Zixi , Sun Yele , Pan Xiaole , Zhu Lili , Wang Zifa
Published: August 2022

The stratospheric contribution to tropospheric ozone has long been a topic of much debate over the past few decades. In this study, we leveraged multiple datasets from surface, sounding and satellite observations to reanalysis datasets, along with a global chemical transport model (Global Nested Air Quality Prediction Modelling System, GNAQPMS) to investigate the impact of a stratospheric-to-tropospheric transport (STT) event characterized by long duration and wide range in the summer on surface high ozone episodes over heavily industrialized regions in northern China. In 14–18 August 2019, the ERA5 reanalysis datasets showed a potential vorticity (PV) tongue and a deep, upper-level trough penetrate towards 35° N over the North China Plain (NCP), indicating the occurrence of a stratospheric intrusion. From Atmospheric Infrared Sounder (AIRS) measurements, we found that the ozone-rich, stratospheric air mass had been injected into the lower altitudes. The GNAQPMS generally captured the featured layers, although there was a slight underestimation in the low troposphere. The averaged magnitudes of stratospheric contribution (O3S) and percentage (O3F) simulated by GNAQPMS were 3–20 μg m−3 and 6%–20%, respectively, while the Whole Atmosphere Community Climate Model (WACCM) indicated a higher stratospheric contribution by 3–5 μg m−3. Through this study, we give our opinions on the controversial topic of a more thorough understanding of the influence of natural processes apart from anthropogenic emissions, even in a heavily polluted region during summer.
1 MeV Au+ ion modification of Fe3O4-based epitaxial films
Authors: Kim-Ngan N-T H , Mackova A , Malinsky P
Published: August 2022

The effect of 1 MeV Au+ ion irradiations on the layer stability of the Fe3O4-based films grown epitaxially on MgO(001) substrates was investigated by Rutherford backscattering spectroscopy (RBS) and RBS-Channelling (RBS-C). The ion mixing effect leads to an appearance of the additional FeO
x
layer and a large enlargement of the thickness of the mixed (Fe,Mg,O) layer in the interfaces. Au+ ions were found to be implanted deeply in the MgO substrate. RBS-C experiments have confirmed that the heavy metallic ion irradiations induce a disorder in the crystalline lattice.
Virus deformation or destruction: size-dependence of antiviral and virucidal activities of gold nanoparticles
Authors: Chaika M , Zahorodnya S , Naumenko K , Pankivska Yu , Povnitsa O , Mukha Iu , Vityuk N , Dorovskih A , Lokshyn M , Lysenko V , Lozovski V , Rusinchuk N
Published: August 2022

Over the last 10 years, the antiviral and antimicrobial activities of non-functionalised inorganic nanoparticles against different pathogens were experimentally shown. This effect has attracted the attention of scientists due to the COVID-19 pandemic; however, its mechanism is still unclear. For understanding the mechanism of nanoparticle’s action, it is important to know how this action depends on the parameters of nanoparticles and the properties of a pathogen. In the work, we have studied the action of gold nanoparticles on the viruses outside and inside the cell and compared this action with two sizes of nanoparticles and two types of viruses. The study has been conducted for adenovirus and H1N1 influenza virus, and gold nanoparticles of 5 nm and 20 nm diameter. Virucidal and antiviral actions were observed experimentally for both sizes of nanoparticles against both viruses. It has also been shown with the electron microscopy that the viruses may be destructed in 2 h after adsorption of 5 nm gold nanoparticles on their surface; and that the viruses may change their shape in 2 h after adsorption of 20 nm nanoparticles on their surface. The model of physical adsorption of nanoparticles on the virus surface due to near-field interaction was used to explain observed results.
Arc-discharge deposition of SWCNTs over SnO2 nanowires for highly sensitive NO2 gas sensor
Authors: Thi Xuan Chu , Hung Chu Manh , Van Duy Nguyen , Ngoc Trinh Minh , Thi Minh Nguyet Quan , Hoa Nguyen Duc
Published: August 2022

The air pollution caused by the emission of NO2 from vehicles in large cities is threatening human health. Thus, a highly sensitive gas sensor is required to monitor this gas. Here, we introduced the arc-discharge deposition of single-walled carbon nanotubes (SWCNTs) over SnO2 nanowires for highly sensitive NO2 gas sensors. The high-quality SnO2 nanowires were grown on-chip on interdigital Pt electrodes, whereas the SWCNTs were deposited by in situ arc-discharge method. To form the heterojunction between SnO2 nanowires and SWCNTs film, we controlled the length of the SnO2 nanowires to avoid bridging of the two electrode fingers while covering the entire surface of Pt electrodes. The SWCNTs were deposited through a shadow mask to ensure the contact between the SWCNTs and SnO2 nanowires but not the Pt electrodes. Electrical measurements confirmed the formation of non-linear contact between SnO2 nanowires and SWCNTs because of the n-p heterojunction. An increment in resistance (decrease in resistance) of the sensor was observed when measured in NO2 gas, indicating the good response characteristics of the device based on heterojunction between SnO2 nanowires and SWCNTs. In addition, gas-sensing measurement at different temperatures indicated that the fabricated sensor could detect low concentrations of NO2 gas in the range of 1–10 ppm, with response values of 20–80. The results demonstrated that the arc-discharge deposition of SWCNTs over SnO2 nanowires is effective for the fabrication of highly sensitive NO2 gas sensors.
Detection of kidney stone using digital image processing: a holistic approach
Authors: Khan Angshuman , Das Rupayan , Parameshwara M C
Published: August 2022

This study presents an ultrasound speckle suppression method to detect the stones in the human kidney. An initial image is first improved using image enhancement techniques, which are used to change the image’s intensities. Next, median filters smooth the picture and eliminate noise. Pre-processed images are segmented using a thresholding technique. The median filter extracts impulsive noise from salt-and-pepper noise. The suggested approach locates stones using location coordinates. Hospital and clinical ultrasound images were used to evaluate the proposed scheme and algorithm. The suggested scheme has been assessed by different performance measuring parameters. Physicians are likely to benefit from the research in terms of clinical diagnosis and educational training. Based on 50 test cases, the proposed plan was correct 96.82% of the time and sensitive 92.16% of the time. Furthermore, the peak signal to noise ratio is 1.82, and the average signal to noise ratio is 1.58, demonstrating the efficacy of the proposed approach.
Cusp types of quotients of hyperbolic knot complements
Authors: Hoffman Neil
Published: August 2022

This paper completes a classification of the types of orientable and non-orientable cusps that can arise in the quotients of hyperbolic knot complements. In particular,

S
2

(
2
,
4
,
4
)

S^2(2,4,4)

cannot be the cusp cross-section of any orbifold quotient of a hyperbolic knot complement. Furthermore, if a knot complement covers an orbifold with a

S
2

(
2
,
3
,
6
)

S^2(2,3,6)

cusp, it also covers an orbifold with a

S
2

(
3
,
3
,
3
)

S^2(3,3,3)

cusp. We end with a discussion that shows all cusp types arise in the quotients of link complements.
Exploring Esports’ Action-Packed Future
Authors: Green Bryony-Hope
Published: August 2022

Esports is one of the biggest and fastest growing industries in the world, with viewership now reaching over 810 million people. But what does the future look like for this avenue of gaming? Bryony-Hope Green explains.
Futurology
Authors: Lucas Matt
Published: August 2022

Matt Lucas FBCS explores his long relationship with retro gaming and tech
How Virtual Reality Can Reduce Pain and Aid Rehabilitation
Authors: Phelan Ivan
Published: August 2022

Ivan Phelan, Director of the Impact VR Lab, Sheffield Hallam University, explains how virtual reality is outperforming therapies across different areas of traditional medicine.
When Will it Get Done? Answering Agile’s Hardest Question
Authors: Hussain Jahanger
Published: August 2022

In a world of complexity, work is unpredictable. Stakeholders want predictability and want to know when it will be done. Jahanger Hussain explores metrics and practices to answer this question in an agile context.
The Digital Skills Network Launch
Authors: Hamilton Jo
Published: August 2022

At a recent event held in its London office and attended by over 70 high-profile guests, BCS announced the Digital Skills Network – a new community founded to meet tomorrow’s societal challenges through filling today’s digital skills gap.
Digital Forensics and Crime Scene Investigation
Authors: Cooper Martin
Published: August 2022

You’ve watched the TV shows, but what really happens – or should happen – when a digital forensics professional arrives on a crimescene? Andrew Moore, Lecturer Practitioner at Anglia Ruskin University, shares the facts.
Computing in Schools
Authors: Cooper Nicki
Published: August 2022

Nicki Cooper explains how IT teachers can embellish the curriculum to prepare digital native children for real-world careers.
Business Analysis and Metaverse
Authors: Chung Kitty
Published: August 2022

Dr Kitty Hung FBCS CITP, Principal Consultant with Atkins, explores what metaverse projects mean for both businesses and also the BAs who will need to embrace the new technology.
Business Analysis
Authors: Lovelock Christina
Published: August 2022

Christina Lovelock MBCS explains how successful change initiatives roll the DICE.
Asymptotic properties of the maximum likelihood estimator in regime-switching models with time-varying transition probabilities
Authors: Li Chaojun , Liu Yan
Published: August 2022

Time-varying transition probability (TVTP) regime-switching models extend the constant regime transition probability in Markov-switching models to include information from observations. We show consistency and asymptotic normality of the maximum likelihood estimator (MLE) in general TVTP regime-switching models where the conditional distribution of $Y_t$ depends on lagged regimes. Consistency of the MLE is also shown under misspecification. The assumptions are verified in regime-switching autoregressive models with widely applied TVTP specifications. A simulation study examines the finite-sample distributions of the MLE and compares the asymptotic variance estimates constructed from the Hessian matrix and the outer product of the score. The simulation results favour the latter. As an empirical example, we compare three leading economic indicators in terms of describing U.S. industrial production.
Impact of echocardiographic analyses of valvular event timing on myocardial work indices
Authors: Olsen Flemming Javier , Bjerregaard Caroline Løkke , Skaarup Kristoffer Grundtvig , Lassen Mats Christian Højbjerg , Johansen Niklas Dyrby , Modin Daniel , Jensen Gorm Boje , Schnohr Peter , Søgaard Peter , Gislason Gunnar , Svendsen Jesper Hastrup , Møgelvang Rasmus , Biering-Sørensen Tor
Published: August 2022

Aims

Valvular event timing is an integral part of echocardiographic pressure–strain loop (PSL) analyses. The impact that different event timing modalities may have on myocardial work indices is unknown.

Methods and results

A methodological study was performed on 200 subjects, including 50 healthy subjects, 50 with aortic valve sclerosis, 50 with atrial fibrillation, and 50 with reduced left ventricular ejection fraction. Valvular event timing was estimated by visual assessment, spectral Doppler, and colour tissue Doppler imaging (TDI) M-mode. These valvular event timings were added to the same PSL analyses sequentially to acquire myocardial work indices, including global work index (GWI). For the 200 participants, the median age was 72 years, 50% were men, and mean blood pressure was 143/80 mmHg. Valvular event timings differed between all three modalities and so did all myocardial work indices. Compared with visual assessment, spectral Doppler resulted in a significantly higher GWI (mean difference: 114 ± 93 mmHg%, P < 0.001), and so did TDI (mean difference: 83 ± 90 mmHg%, P < 0.001). A higher GWI by spectral Doppler than by TDI was also observed (mean difference: 30 ± 53 mmHg%, P < 0.001). In the healthy subgroup, a systematic bias was observed for spectral Doppler compared with visual assessment (mean difference: 160 ± 77 mmHg%, P < 0.001), and a similar trend was noted for TDI vs. visual assessment (mean difference: 124 ± 74 mmHg%, P < 0.001).

Conclusion

Myocardial work indices differ depending on the event timing modality used, with visual assessment yielding lower GWI values compared with Doppler-based methods. Serial PSL analyses should apply the same event timing method.
Aging Is Associated With Multidirectional Changes in Social Cognition: Findings From an Adult Life-Span Sample Ranging From 18 to 101 Years
Authors: Grainger Sarah A , Crawford John D , Riches Julia C , Kochan Nicole A , Chander Russell J , Mather Karen A , Sachdev Perminder S , Henry Julie D
Published: August 2022

Objectives

Normal adult aging is associated with changes in social cognition. Although 4 social cognitive domains have been identified (social perception, theory of mind [ToM], affective empathy, and social behavior), no study has tested all 4 domains concurrently in a life-span sample, limiting understanding of the relative magnitude of age-related changes across domains. This study addresses this gap by providing the first assessment of all 4 social cognitive domains in an adult life-span sample.

Methods

Three hundred and seventy-two participants ranging from 18 to 101 years of age took part in this study. Participants completed a testing battery that assessed social perception, ToM, affective empathy, and social behavior, as well as broader cognitive function and well-being.

Results

The results showed that adult aging is associated with multidirectional changes in social cognitive abilities, with ToM and social perception showing nonlinear decline across much of the life-span, and affective empathy and social behavior showing improvement. Age remained a significant predictor of all 4 social cognitive domains, even after accounting for broader cognitive function. Weak associations emerged between some of the social cognitive abilities and and indices of broader well-being.

Discussion

These findings provide novel and important evidence that normative aging is associated with both gains and losses in social cognition that occur at distinct points of the adult life-span, and that are at least partially independent of general age-related cognitive decline.
Learning source, path and site effects: CNN-based on-site intensity prediction for earthquake early warning
Authors: Zhang Hongcai , Melgar Diego , Sahakian Valerie , Searcy Jake , Lin Jiun-Ting
Published: August 2022

To provide timely and accurate seismic alerts for potential users during the earthquake early warning (EEW) process, several algorithms have been proposed and implemented. Some of the most common rely on the characterization of the earthquake magnitude and location, and then use a ground motion model to forecast shaking intensity at a user's location. It has been noted that with this approach the scatter in the forecasted intensities can be significant and may affect the reliability and usefulness of the warnings. To ameliorate this, we propose a single station machine learning (ML) algorithm. We build a four-layer convolutional neural network (CNN), named it CONIP (Convolutional neural network ONsite Intensity Prediction), and test it using two data sets to study the feasibility of seismic intensity forecasting from only the first few seconds of a waveform. With only limited waveforms, mainly P waves, our CONIP model will forecast the on-site seismic intensity. We find that compared with existing methods, the forecasted seismic intensities are much more accurate. To understand the nature of this improvement we carry out a residual decomposition and quantify to what degree the ML model learns site, regional path, and source information during the training. We find that source and site effects are easily learned by the algorithm. Path effects, on the other hand, can be learned but will depend largely on the number, location, and coverage of stations. Overall, the ML model performance is a substantial improvement over traditional approaches. Our results are currently only applicable for small and moderate intensities but, we argue, could in future work be supplemented by simulations to supplement the training data sets at higher intensities. We believe that ML algorithms will play a dominant role in the next generation of EEW systems.
Effect of fear appeal mobile phone messaging on health behaviors of caregivers with children under-five in Ghana
Authors: Mohammed Aliyu , Desu Adwoa Pinamang , Acheampong Princess Ruhama , Mensah Kofi Akohene , Osei Francis Adjei , Yeboah Eugene Osei , Amanor Ernest , Owusu-Dabo Ellis
Published: August 2022

Social and Behavior Change Communication is a vital strategy in the control of malaria. However, the effectiveness of fear appeal tactic as a preventive strategy remains uncertain. This study examined the influence of a fear appeal mobile phone-based intervention, guided by Witte’s Extended Parallel Process model, on malaria prevention among caregivers with children under-five. We conducted a quasi-experimental study of a 12-month intervention using a sample of 324 caregivers from two rural districts, assigned to either an intervention or control group. The intervention group received fear appeal voice Short Message Service (SMS), once a week for twelve (12) months, while caregivers in the control group received none. The results showed that exposure to the messages was associated with an increased odds of positive attitude [adjusted Odds ratio (aOR) = 2.58; 95% CI 1.61–4.15] and behavioral changes (aOR = 2.03, 95% CI 1.29–3.19). The intervention group exhibited lower odds of defensive avoidance (aOR = 0.44, 95% CI 0.29–0.68) and message minimization (aOR = 0.51, 95% CI 0.33–0.78) compared with the control group. These findings highlight the importance of communicating health messages via mobile phones using fear appeal for improving the health behaviors of caregivers. This strategy, however, may not be useful for influencing the intention of caregivers to engage in positive health practices to protect their children from malaria.