bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal biphotons
Authors: Lib Ohad , Bromberg Yaron
Published: March 2022

The observation of the Hanbury Brown and Twiss (HBT) effect with thermal light marked the birth of quantum optics. All the thermal sources considered to date did not feature quantum signatures of light, as they consisted of independent emitters that emit uncorrelated photons. Here, we propose and demonstrate an incoherent light source based on phase-randomized spatially entangled photons, which we coin thermal biphotons. We show that in contrast to thermal light, the width of the HBT peak for thermal biphotons is determined by their correlations, leading to violation of the Siegert relation and breakdown of the speckle-fluctuations interpretation. We further provide an alternative interpretation of the results by drawing a connection between the HBT effect and coherent backscattering of light. Finally, we discuss the role of spatial entanglement in the observed results, deriving a relation between the Schmidt number and the degree of violation of the Siegert relation under the double-Gaussian approximation of spontaneous parametric down conversion. Our work reflects new insights on the coherence properties of thermal light in the presence of entanglement, paving the way for entanglement certification using disorder averaged measurements.
An icosanuclear silver(I) cluster supported by bis(thiosemicarbazonato) ligands
Authors: Paterson Brett M. , White Jonathan M. , Donnelly Paul S.
Published: March 2022

The synthesis and structural characterisation of an icosanuclear silver(I) cluster complex is reported here. The complex includes twenty silver(I) ions supported by eighteen bis(thiosemicarbazonato) ligands. The cluster of silver(I) ions involves several close Ag⋯Ag contacts suggesting some degree of argentophilic interactions and the bis(thiosemicarbazonato) ligands are present in three different conformations highlighting the ability of thiosemicarbazone ligands to coordinate to metal ions in different modes.
PERK reprograms hematopoietic progenitor cells to direct tumor-promoting myelopoiesis in the spleen
Authors: Liu Mingyu , Wu Chong , Luo Shufeng , Hua Qiaomin , Chen Hai-Tian , Weng Yulan , Xu Junyu , Lin Huiling , Wang Lu , Li Jinheng , Zhu Lan , Guo Zhenhong , Zhuang Shi-Mei , Kang Tiebang , Zheng Limin
Published: March 2022

The spleen is an important site of hematopoietic stem/progenitor cell (HSPC) preconditioning and tumor-promoting myeloid cell generation in cancer, but the regulatory mechanism remains unclear. Here, we found that PKR-like endoplasmic reticulum kinase (PERK) mediated HSPC reprogramming into committed MDSC precursors in the spleen via PERK–ATF4–C/EBPβ signaling. Pharmacological and genetic inhibition of this pathway in murine and human HSPCs prevented their myeloid descendant cells from becoming MDSCs even with subsequent exposure to tumor microenvironment (TME) factors. In mice, the selective delivery of PERK antagonists to the spleen was not only sufficient but more effective than the tumor-targeted strategy in preventing MDSC activation in the tumor, leading to profound TME reshaping and tumor regression. Clinically, HSPCs in the spleen of cancer patients exhibit increased PERK signaling correlated with enhanced myelopoiesis. Our findings indicate that PERK-mediated HSPC preconditioning plays a crucial role in MDSC generation, suggesting novel spleen-targeting therapeutic opportunities for restraining the tumor-promoting myeloid response at its source.
Occupational external exposure to ionizing radiation in research-associated activities in Iran (2015-2020)
Authors: Hosseini Pooya S M , Hosseinipanah M
Published: March 2022

Research is an integral part of radiological and nuclear activities; thus, workers may receive different levels of occupational exposure. In the present study, occupational external exposure of workers was studied at the largest radiological and nuclear research institute of Iran from 2015–2020. The activities included research reactors, nuclear fuel cycle, development on radiopharmaceuticals and radioisotopes, particle accelerators, plasma and fusion, and nuclear agriculture. The average doses of the monitored and exposed workers were calculated to be 0.095 and 0.575 mSv, respectively, which were around their corresponding worldwide values. Moreover, the results showed that in comparison with other research activities, the workers in research reactors, nuclear fuel cycle, and development of radiopharmaceuticals and radioisotopes may face higher occupational risks. It could be, therefore, concluded that all the radiation protection measures have been effective at achieving safe research activities in Iran.
Soft measurement of ball mill load under variable working conditions based on deep transfer learning
Authors: Huang Peng , Guo Jiaming , Sang Gao , Miao Qiuhua , Jia Minping
Published: March 2022

In actual industrial production, labeled sample data of a ball mill is difficult to obtain under variable working conditions. Aiming to realize the soft measurement of ball mill load under variable working conditions, a joint discriminative high-order moment alignment network (JDMAN) is proposed, based on the deep transfer learning in this paper. With this method, discriminative features were learned through jointly training labeled samples belonging to the source domain and unlabeled samples belonging to the target domain. Simultaneously, the features learned by a deep convolution network were aligned and clustered through central moment discrepancy and center loss to accomplish transfer. The comparison with other transfer methods indicates that the proposed JDMAN can effectively promote the accuracy of soft measurement under variable working conditions.
Mechanical characteristics of Ni50Co50/Ni substrate during indentation by molecular dynamics
Authors: Pham Anh-Vu , Fang Te-Hua , Nguyen Van-Thuc , Chen Tao-Hsing
Published: March 2022

Coating an alloys film onto a metallic surface could dramatically improve the surface quality. This report studies the microstructure and intermixing phenomena of Ni50Co50 film deposited on Ni(001) substrate with flat, asperity and trench Ni surfaces by molecular dynamics (MD) simulation. The effects of the film thickness and loading velocity on the mechanical properties and deformation behaviours of the sample are also surveyed by indentation. The results represent that the intermixing and lattice structure of the film is enhanced after annealing. Moreover, the sample hardness is improved as the deposited Ni50Co50 film when the film thickness rising from 18 to 38 Å. In contrast, the structure transformation rate and dislocations density of the sample decrease when the Ni50Co50 film becomes thicker. Interestingly, the plastic deformation rate and dislocation density of the sample at the trench surface are higher than the flat one. Besides, the increase of the loading velocity gives rise to the plastic deformation and the local stress rates. The dislocation density of the Ni50Co50/Ni sample is reduced if the loading speed is high enough.
Power law fitting of the ion saturation current and the three-temperature Maxwellian EEDF in a multi-dipole confined hot cathode discharge: an experimental revisitation
Authors: Yip Chi-Shung , Jin Chenyao , Zhang Wei , Jiang Di , Xu Guo-Sheng
Published: March 2022

Langmuir probe diagnostic in a multi-dipole confined hot cathode discharge has been revisited with an improved sheath expansion model with fitted expansion parameters. The results show a three-temperature Maxwellian EEDF composition also observed in previous studies using a very similar system. The dependence on neutral pressure and discharge current of each electron species are consistent with known physical processes in a multi-dipole confined hot cathode discharge. This shows that the employment of the new ion saturation fitting method does not eliminate the contribution of the high energy degraded primaries to the Langmuir probe I–V trace, as sheath expansion and high energy electron current contributes differently on an I–V trace. The result remains supportive to the existence of a very hot (T
dp > 15 eV) degraded primary electron species separate from the typical hot electron (T
hot ∼ 3 eV) species. Thus it is recommended to sweep the Langmuir probe beyond the bias voltage of the hot cathode, whenever possible, in order to properly resolve the contribution to the I–V trace of the degraded primaries.
Self-sensing magnetostrictive actuator based on ΔE effect: design, theoretical modeling and experiment
Authors: Xie Dongjian , Yang Yikun , Yang Bintang
Published: March 2022

Giant magnetostrictive material (GMM) has the smart potential to be integrated as a self-sensing actuator. This paper presents a novel self-sensing giant magnetostrictive actuator (SSGMA), by sensing the on-line stiffness of the actuator upon the ΔE effect. A self-sensing signal is generated by superimposing a set of high-frequency small sensing excitation magnetic fields on low-frequency static or quasi-static driving magnetic fields. The fully coupled magneto-elastic-thermal nonlinear constitutive model of GMM is derived, and then the self-sensing response model of the SSGMA based on the nonlinear equivalent piezomagnetic equation is proposed. On the theoretical basis, the influences of magnetic field, prestress and temperature on the ΔE effect, the equivalent piezomagnetic equation parameters and the SSGMA sensing signal are investigated in detail, respectively. Moreover, a prototype of the SSGMA is fabricated and tested for self-sensing performance. The experimental results demonstrate the effectiveness of the theoretical analysis, and further show that the proposed SSGMA achieves self-sensing output displacement within a stroke of nearly 50 μm, with a sensitivity of 2.49 mV μm−1. The self-sensing displacement resolution of the SSGMA by far may reach 63.4 nm after experimental determination. This novel self-sensing actuator with micron-level self-sensing drive capability can be integrated into an external sensorless execution system in the future.
Input shaping for travelling wave generation
Authors: Bhayadia Amit , Olivett Anthony , Singh Tarunraj , Karami M Amin
Published: March 2022

Travelling wave patterns observed in the movement of certain aquatic animals has motivated research in the modification of flow behavior, especially to deal with boundary layer separation in airplane wings. Research has shown that inducing travelling waves on the top surface of the wing can generate sufficient momentum to prevent boundary layer separation without increasing the drag. Due to this effect of propagating waves on the aerodynamics, generation of travelling waves on solid surfaces is being widely studied. Recently, methods such as two-mode excitation, active sink and impedance matching have shown promise in generation of uniform travelling waves in solids with the help of piezo electric actuators. Unfortunately, there are some challenges involved in the experimental application of these methods. Although these techniques have shown to be adequate in laboratory settings, they require laborious tuning procedures which do not guarantee desired trajectories and are followed in light of interference from unwanted modes and their transients. Some methods rely on selective mode excitation, which can cause interference from unwanted modes if the transient behavior of the system is not accounted for. Feed-forward input shaping control methods are proposed that augment the open-loop piezo actuation method (two-mode excitation) and provide a more robust method for generating uniform travelling waves. The input shaping control alters the reference signal such that the parasitic behavior of unnecessary modes is cancelled out. The combination of the mode suppression and selective mode excitation through input shaping is verified experimentally for generation of a smooth travelling waves in finite structures.
Interaction of short wavelength photons with atomic and molecular ions: 50 years some examples
Authors: Kennedy Eugene T
Published: March 2022

Steve Manson has been involved with the study of the photoionisation of atomic ions since the early 70’s. Over the half century since, much has happened in terms of theory and experiment. This short paper provides some examples of the inner-shell photoionisation of atomic ions, which demonstrate different experimental approaches and the important ongoing symbiotic nature of combined theoretical and experimental studies. Recent initiatives in the study of the photoionisation of small molecular ions are also briefly described.
Cosmological perturbation theory in f(Q,T) gravity
Authors: Nájera Antonio , Fajardo Amanda
Published: March 2022

We developed the cosmological linear theory of perturbations for f(Q,T) gravity, which is an extension of symmetric teleparallel gravity, with Q the non-metricity and T the trace of the stress-energy tensor. By considering an ansatz of f(Q,T) = f
1(Q)+f
2(T), which has been broadly studied in the literature and the coincident gauge where the connection vanishes, we got equations consistent with f(Q) gravity when fT
= 0. In the case of the tensor perturbations, the propagation of gravitational waves was found to be identical to f(Q), as expected. For scalar perturbations, outside the limit fT
= 0, we got that the coupling between Q and T in the Lagrangian produces a coupling between the perturbation of the density and the pressure. This coupling is preserved when considering the weak coupling limit between Q and T. On the other hand, in the strong coupling limit with a generic function of the form f
2(T) = αT + β T
2, the perturbative equations are heavily driven by the f
2(T) derivatives when β ≠ 0. However, when β = 0, the perturbative equations are identical to the weak coupling limit even though this case is a non-minimally coupling one. The presence of T in the Lagrangian breaks the equation of the conservation of energy, which in turn breaks the standard ρ' + 3𝓗 (ρ+p) = 0 relation. We also derived a coupled system of differential equations between δ, the density contrast and v in the 𝓗 ≪ k limit and with negligible time derivative of the scalar perturbation potentials, which will be useful in future studies to see whether this class of theories constitute a good alternative to dark matter. These results might also enable to test f(Q,T) gravity with CMB and standard siren data that will help to determine if these models can reduce the Hubble constant tension and if they can constitute an alternative to the ΛCDM model.
Higher derivative scalar tensor theory in unitary gauge
Authors: Joshi Pawan , Panda Sukanta
Published: March 2022

Ostrogradsky instability generally appears in nondegenerate higher-order derivative theories and this issue can be resolved by removing any existing degeneracy present in such theories. We consider an action involving terms that are at most quadratic in second derivatives of the scalar field and non-minimally coupled with the curvature tensors. We perform a 3+1 decomposition of the Lagrangian to separate second-order time derivative terms from rest. This decomposition is useful for checking the degeneracy hidden in the Lagrangian and helps us find conditions under which Ostrogradsky instability does not appear. We show that our construction of Lagrangian resembles that of a GR-like theory for a particular case in the unitary gauge. As an example, we calculate the equation of motion for the flat FRW. We also write the action for open and closed cases, free from higher derivatives for a particular choice derived from imposing degeneracy conditions.
On the origin of red spirals: does assembly bias play a role?
Authors: Sarkar Suman , Pandey Biswajit , Das Apashanka
Published: March 2022

The formation of the red spirals is a puzzling issue in the
standard picture of galaxy formation and evolution. Most studies
attribute the colour of the red spirals to different environmental
effects. We analyze a volume limited sample from the SDSS to study
the roles of small-scale and large-scale environments on the colour
of spiral galaxies. We compare the star formation rate, stellar age
and stellar mass distributions of the red and blue spirals and find
statistically significant differences between them at 99.9%
confidence level. The red spirals inhabit significantly denser
regions than the blue spirals, explaining some of the observed
differences in their physical properties. However, the differences
persist in all types of environments, indicating that the local
density alone is not sufficient to explain the origin of the red
spirals. Using an information theoretic framework, we find a small
but non-zero mutual information between the colour of spiral
galaxies and their large-scale environment that are statistically
significant (99.9% confidence level) throughout the entire length
scale probed. Such correlations between the colour and the
large-scale environment of spiral galaxies may result from the
assembly bias. Thus both the local environment and the assembly bias
may play essential roles in forming the red spirals. The spiral
galaxies may have different assembly history across
all types of environments. We propose a picture where the
differences in the assembly history may produce
spiral galaxies with different cold gas content. Such a difference
would make some spirals more susceptible to quenching. In all
environments, the spirals with high cold gas content could delay the
quenching and maintain a blue colour, whereas the spirals with low
cold gas fractions would be easily quenched and become red.
Generalization of the theory of three-dimensional quantum Hall effect of Fermi arcs in Weyl semimetal
Authors: Chang Mingqi , Ge Yunfeng , Sheng Li
Published: March 2022

The quantum Hall effect (QHE), which is usually observed in two-dimensional systems, was predicted theoretically and observed experimentally in three-dimensional (3D) topological semimetal. However, there are some inconsistencies between the theory and the experiments showing the theory is imperfect. Here, we generalize the theory of the 3D QHE of Fermi arcs in Weyl semimetal. Through calculating the sheet Hall conductivity of a Weyl semimetal slab, we show that the 3D QHE of Fermi arcs can occur in a large energy range and the thickness dependences of the QHE in different Fermi energies are distinct. When the Fermi energy is near the Weyl nodes, the Fermi arcs give rise to the QHE which is independent of the thickness of the slab. When the Fermi energy is not near the Weyl nodes, the two Fermi arcs form a complete Fermi loop with the assistance of bulk states giving rise to the QHE which is dependent on the sample thickness. We also demonstrate how the band anisotropic terms influence the QHE of Fermi arcs. Our theory complements the imperfections of the present theory of 3D QHE of Fermi arcs.
Drop impact on substrates with heterogeneous stiffness
Authors: Cheng Yang , Zheng Jian-Gen , Yang Chen , Yuan Song-Lei , Chen Guo , Liu Li-Yu
Published: March 2022

Previous studies of drop impact mainly focus on homogeneous substrates while heterogeneous substrates remain largely unexplored. A convenient preparation strategy of stiff heterogeneous substrates is presented in this work, and the drop impact on such a stiffness-patterned substrate consisting of soft spirals surrounded by a rigid region is systematically investigated. The results show that the splash behavior of a drop on a stiffness-patterned substrate exhibits distinct characteristics from those on a homogeneous substrate. Prompt splash is more likely to occur on the substrate with the greater heterogeneity of stiffness, which is reflected in the lower critical impact velocity. Moreover, the splash velocity of emitted droplet is significantly larger on the heterogeneous substrate than that on a corresponding homogeneous substrate, especially at a higher impact velocity of the drop, indicating a stronger splash intensity on the heterogeneous substrate. The difference in drop splashing between homogeneous substrate and heterogeneous substrate is largely due to the stiffness heterogeneity, rather than the variation of overall stiffness of the substrate. The use of spiral shape provides a feasible solution for introducing stiffness heterogeneity of substrate. This study is conducive to the understanding of drop impact research beyond uniform substrates, reveals the potential of using stiffness-patterned substrates to control splash, and may find useful applications in industries related to drop impact and splash.
Tunable anharmonicity versus high-performance thermoelectrics and permeation in multilayer (GaN)1–x
(ZnO)
x
Authors: Liang Hanpu , Duan Yifeng
Published: March 2022

Nonisovalent (GaN)1−x
(ZnO)
x
alloys are more technologically promising than their binary counterparts because of the abruptly reduced band gap. Unfortunately, the lack of two-dimensional (2D) configurations as well as complete stoichiometries hinders to further explore the thermal transport, thermoelectrics, and adsorption/permeation. We identify that multilayer (GaN)1−x
(ZnO)
x
stabilize as wurtzite-like Pm-(GaN)3(ZnO)1, Pmc21-(GaN)1(ZnO)1, P3m1-(GaN)1(ZnO)2, and haeckelite C2/m-(GaN)1(ZnO)3 via structural searches. P3m1-(GaN)1(ZnO)2 shares the excellent thermoelectrics with the figure of merit ZT as high as 3.08 at 900 K for the p-type doping due to the ultralow lattice thermal conductivity, which mainly arises from the strong anharmonicity by the interlayer asymmetrical charge distributions. The p–d coupling is prohibited from the group theory in C2/m-(GaN)1(ZnO)3, which thereby results in the anomalous band structure versus ZnO composition. To unveil the adsorption/permeation of H+, Na+, and OH− ions in AA-stacking configurations, the potential wells and barriers are explored from the Coulomb interaction and the ionic size. Our work is helpful in experimental fabrication of novel optoelectronic and thermoelectric devices by 2D (GaN)1−x
(ZnO)
x
alloys.
Anomalous diffusion in branched elliptical structure
Authors: Suleiman Kheder , Zhang Xuelan , Wang Erhui , Liu Shengna , Zheng Liancun
Published: March 2022

Diffusion in narrow curved channels with dead-ends as in extracellular space in the biological tissues, e.g., brain, tumors, muscles, etc. is a geometrically induced complex diffusion and is relevant to different kinds of biological, physical, and chemical systems. In this paper, we study the effects of geometry and confinement on the diffusion process in an elliptical comb-like structure and analyze its statistical properties. The ellipse domain whose boundary has the polar equation

ρ

(
θ
)

=

b

1
−

e
2

cos

2

θ

with 0 < e < 1, θ ∈ [0,2π], and b as a constant, can be obtained through stretched radius r such that Υ = r ρ (θ) with r ∈ [0,1]. We suppose that, for fixed radius r = R, an elliptical motion takes place and is interspersed with a radial motion inward and outward of the ellipse. The probability distribution function (PDF) in the structure and the marginal PDF and mean square displacement (MSD) along the backbone are obtained numerically. The results show that a transient sub-diffusion behavior dominates the process for a time followed by a saturating state. The sub-diffusion regime and saturation threshold are affected by the length of the elliptical channel lateral branch and its curvature.
Modulation of Schottky barrier in XSi2N4/graphene (X = Mo and W) heterojunctions by biaxial strain
Authors: Liang Qian , Luo Xiang-Yan , Wang Yi-Xin , Liang Yong-Chao , Xie Quan
Published: March 2022

Reducing the Schottky barrier height (SBH) and even achieving the transition from Schottky contacts to Ohmic contacts are key challenges of achieving high energy efficiency and high-performance power devices. In this paper, the modulation effects of biaxial strain on the electronic properties and Schottky barrier of MoSi2N4 (MSN)/graphene and WSi2N4 (WSN)/graphene heterojunctions are examined by using first principles calculations. After the construction of heterojunctions, the electronic structures of MSN, WSN, and graphene are well preserved. Herein, we show that by applying suitable external strain to a heterojunction stacked by MSN or WSN — an emerging two-dimensional (2D) semiconductor family with excellent mechanical properties — and graphene, the heterojunction can be transformed from Schottky p-type contacts into n-type contacts, even highly efficient Ohmic contacts, making it of critical importance to unleash the tremendous potentials of graphene-based van der Waals (vdW) heterojunctions. Not only are these findings invaluable for designing high-performance graphene-based electronic devices, but also they provide an effective route to realizing dynamic switching either between n-type and p-type Schottky contacts, or between Schottky contacts and Ohmic contacts.
HGCROC3: the front-end readout ASIC for the CMS High Granularity Calorimeter
Authors: Bouyjou F. , Bombardi G. , Dulucq F. , El Berni A. , Extier S. , Firlej M. , Fiutowski T. , Guilloux F. , Idzik M. , De La Taille C. , Marchioro A. , Molenda A. , Moron J. , Swientek K. , Thienpont D. , Vergine T.
Published: March 2022

For the CMS High Granularity Calorimeter (CE), the final version of the 72-channel front-end ASIC (HGCROC3) was submitted in December 2020. HGCROC3 includes low-noise/high-gain preamplifiers/shapers and a 10-bit 40 MHz successive approximation ADC (SAR-ADC) that provide the charge measurement over the linear range of the preamplifier. In the saturation range, a discriminator and a time-to-digital converter (TDC) provide the charge information from the time over threshold (ToT; 200 ns dynamic range, 50 ps binning). A fast discriminator and another TDC provide timing information to 25 ps accuracy. The chip embeds all necessary ancillary services: bandgap circuit, PLL, threshold DACs. We present the experimental results on the latest and final version (HGCROC3) received in April 2021.
Using snapshot measurements to identify high-emitting vehicles
Authors: Qiu Minghao , Borken-Kleefeld Jens
Published: March 2022

Policy makers have long been interested in detecting ‘high-emitters’, a supposedly small fraction of vehicles that make disproportionally large contributions to total fleet emissions. However, existing identification schemes often exclusively rely on snapshot measurements (i.e. emissions within less than a second), and thus simply identify vehicles with high instantaneous emissions, instead of vehicles with high average emissions over a driving period as regulated by emission standards. We design a comprehensive scheme to address this challenge by combining fleetwide remote sensing measurements with detailed second-by-second emission measurements from individual vehicles. We first determine the trip-average NO
x
emission rates of individual vehicles in a Euro-5 diesel fleet measured across European locations; this allows, second, to calculate the fraction and emission contributions of high-emitters based on trip-average emission. We demonstrate that the identification of high-emitters is quite uncertain as long as it is based on single snapshots only; but 80% of the high-emitters can be identified with over 75% precision with five or more repeated measurements of the same vehicle. Compared to the conventional detection schemes, our scheme can increase the identified high-emitters and associated emission reductions by over 140%. Our method is validated and shown to be superior to the conventional interpretation of snapshot measurements.
Intra-annual relationship between precipitation and forest disturbance in the African rainforest
Authors: Gou Yaqing , Balling Johannes , De Sy Veronique , Herold Martin , De Keersmaecker Wanda , Slagter Bart , Mullissa Adugna , Shang Xiaocheng , Reiche Johannes
Published: March 2022

Analysis of forest disturbance patterns in relation to precipitation seasonality is important for understanding African tropical forest dynamics under changing climate conditions and different levels of human activities. Newly available radar-based forest disturbance information now enables an investigation of the intra-annual relationship between precipitation and forest disturbance in a spatially and temporally explicit manner, especially in the tropics, where frequent cloud cover hinders the use of optical-based remote sensing products. In this study, we applied cross-correlation on monthly precipitation and forest disturbance time series for 2019 and 2020 at a 0.5° grid in the African rainforest. We used the magnitude of the correlation and time lag to assess the intra-annual relationship between precipitation and forest disturbance, and introduced accessibility proxies to analyse the spatial variation of the relationship. Results revealed that a significant negative correlation between forest disturbance and precipitation dominates the study region. We found that significant negative correlations appear on average closer to settlements with overall smaller variations in travel time to settlements compared to grid cells with non-significant and significant positive correlation. The magnitude of the negative correlation increases as the travel time to settlements increases, implying that forest disturbances in less accessible areas are more affected by precipitation seasonality and that in particular human-induced disturbance activities are predominantly carried out in the drier months. Few areas showed a significant positive correlation, mainly resulting from natural causes such as flooding. These new insights in the interaction between forest disturbance, precipitation and accessibility provide a step forward in understanding the complex interactions that underlie the complexity of forest loss patterns that we can increasingly capture with Earth Observation approaches. As such, they can support forest conservation and management in coping with climate change induced changes of precipitation patterns in African rainforest countries.
On electron propagation in triangular graphene quantum dots
Authors: Hrivnák Jiří , Motlochová Lenka
Published: March 2022

Tight-binding models of electron propagation in single-layer triangular graphene quantum dots with armchair and zigzag edges are developed. The electron hoppings to the nearest and next-to-nearest neighbours on the honeycomb lattice as well as interactions with the confining Dirichlet and Neumann walls are incorporated into the resulting tight-binding Hamiltonians. Associated to the irreducible crystallographic root system A
2, the armchair and zigzag honeycomb Weyl orbit functions together with the related discrete Fourier–Weyl transforms provide explicit exact forms of the electron wave functions and energy spectra. The electronic probability densities corresponding to the armchair and zigzag dots are evaluated and their contrasting behaviour exemplified.
Identifying High-risk Areas of Dengue by Meteorological factors in Thailand
Authors: Langkulsen Uma , Sakolnakhon Kamol Promsakha na
Published: March 2022

Dengue is a public health problem in Thailand. This study aimed to investigate the spatial distribution pattern and meteorological factors associated with dengue in the central region over the past 10 years. Dengue incidence and meteorological data were collected from 2007 to 2016. Geographical information system modeling was done to generate sub-district level risk map of dengue incidences, with five risk levels. The findings revealed that mean temperature, rainfall, relative humidity, and wind speed are important meteorological factors that influence component of dengue disease occurrence. The identified sub-district level risk estimates can be very useful in planning and executing dengue control in Thailand.
Modelling of Aromatic Sulfur Compounds Adsorption from Hydrocarbon Fuels by Biochar Based Adsorbent
Authors: Uzunova S , Minchev L , Uzunov I
Published: March 2022

In this work model fuel containing thiophene, benzothiophene and dibenzothiophene in different concentration combinations were treated with biochar. The quantity of total sulfur into the stock mixed solutions was below 1000 ppm. The adsorbent was prepared by pyrolysis of rice husks. The investigation aimed to use the method of multiple linear regression to derive a mathematical model, describing the adsorption of the three aromatic sulfur compounds from single and multi-component solutions of model fuel. The model describing the adsorption from multi-component solutions, based on the experimental results, has a correlation coefficient of 0.961. It reveals that the degree of desulfurization does not depend on the concentration of thiophene, but only on the concentrations of benzothiophene and dibenzothiophene in the fuel. The model can be used to predict the level of the adsorptive purification of the fuel if the content of benzothiophene and dibenzothiophene in it is known.
Recent Norwegian Research Relevant to Evacuation, Search and Rescue under Arctic Conditions
Authors: Gudmestad Ove T.
Published: March 2022

Marine traffic is increasing in the Arctic Region. As ice in the Arctic Region retracts, opportunities for the marine industry increase. This relates to the fishing industry, which is moving further into the Arctic Seas, the shipping industry, which is using the Northern Sea Route, particularly for transporting liquefied natural gas, and the cruise industry, which is transporting passengers to the last frontier on the globe. The question has been raised: Are the marine industry’s activities in the Arctic Region safe for people, the environment and assets? The International Maritime Organization’s (IMO) Polar Code, which came into force in 2017 sets requirements for ships and procedures, as well as for the competence of those involved. In particular, there have been uncertainties regarding how people on board a ship in distress can be saved should it be necessary to abandon ship. The question is of considerable concern in Norway, which is a main stakeholder in the Arctic Region, with the involvement/passage of many fishing, cargo and cruise vessels. Over several years, considerable research has therefore been carried out to review the status of safe operations in the Arctic Region and to identify methods to improve the safety of all involved in the Arctic maritime traffic. This paper presents a summary of recent Norwegian research relevant to safe evacuation, search and rescue under Arctic conditions. The summary includes the outcome of the Norwegian research programme, Sarinor, the SARex exercises carried out by the University of Stavanger, the Norwegian Coast Guard and the industrial company GMC (Stavanger) in 2016, 2017 and 2018, as well as follow-up research carried out later. Its implementation in the IMO is also discussed. Finally, thoughts on continuing the work to further improve safety are presented.
Anthropogenic Contamination of the Atoyac River, México
Authors: Estrada Rivera A. , Díaz Fonseca A. , Treviño Mora S. , García Suastegui W.A. , Castelán Vega R del C.  , Chávez Bravo E. , Zayas Pérez M.T , Morán Perales J.L. , Handal Silva A.
Published: March 2022

The Atoyac River that crosses Puebla-Tlaxcala in Mexico shows a severe state of contamination, however, this situation has been scarcely studied. The objective of this work was to evaluate the pollutants in the Atoyac River (physicochemical parameters, heavy metals and volatile solvents) in three areas that comprise the state of Puebla and Tlaxcala from samples collected in August 2019. The study areas were San Cristóbal Tepetlaxco Puebla (Zone 1), San Martín Texmelucan Puebla (Zone 2) and Villa Alta Tlaxcala (Zone 3). The results of the determination of the physicochemical parameters (Temperature, pH, Conductivity, Turbidity, COD, BOD5 and DO), heavy metals and volatile organic solvents reveal that Zone 1 represents the least contaminated area while Zone 3 has a critical contamination due to the presence of physicochemical values and concentrations of heavy metals and organic solvents that exceed the limits allowed by the Official Mexican Standards. Therefore, our results suggest that the Atoyac River is affected in a heterogeneous way. Observing the increase in pollution dramatically and progressively. Hence, it is urgent to generate information that serves as evidence to make recommendations to curb excessive industrial and municipal pollution, which can cause problems for the environment and health of the population.
Influence of Influent Quality and Operational Modes on the Excessive Growth of Filamentous Bacteria in Kuwait’s Activated Sludge Systems
Authors: Abusam Abdallah , Al-Salameen Fadila
Published: March 2022

Kuwait’s wastewater treatment plants experience severe sludge bulking and foaming problems during the winter months. In an effort to identify the possible causes of these problems, sample of wastewater and sludge was collected from Um-Al-Haiman and Riqqa activated sludge systems each week for 32 weeks. The quality of wastewater was determined following standard methods of water analysis, while the dominant filamentous bacteria were identified and quantified using a molecular method called Vermicon Identification Technology (VIT). Multivariate statistical analysis (namely, Pearson’s correlation analysis and principal component analysis) was then carried out on the obtained datasets of results. Pearson’s correlation analysis revealed several significant associations between filamentous bacteria growth and influent quality and operational modes for the systems. The principal component analysis revealed six components that accounted for more than 70% of the total datasets’ information. The techniques used in this study can also be used to assess the relationship between filamentous bacteria growth and the operating conditions of other activated sludge systems.
Water-saving Strategies in the Face of Water Shortage Crisis: A Case Study of Science Museum in Taiwan
Authors: Wang Y H , Ger T H , Lou J R , Chang Chien C T
Published: March 2022

In the past two years, Taiwan has rarely experienced the typhoons that usually bring her abundant rainfall. The southern region, in particular, is facing a severe crisis of water shortage. Meanwhile, the National Science and Technology Museum (NSTM), in Kaohsiung, Southern Taiwan, has launched several exhibitions and activities, seeking to attract large numbers of visitors. These events consume much water, in the midst of a water crisis. In the face of such a crisis, water-saving strategies are critical. Thus, using qualitative interviews and analyses, this research found that water-saving activities organized by NSTM were effective in reminding people to conserve water. Our analysis also shows that the strategy of building a rainwater harvesting system as an alternative water source can save as much as 4.94% of tap water. These achievements make the NSTM initiative a good exemplar of water-saving strategies.
Cell Biological Effects of Long-term Exposure to Electromagnetic Field of Simulated Mobile Phones
Authors: Oskouei Kiana , Khodahemmati Sara , XiaoJin Su , Rafiee Sara , Gao Jingfeng , Wang Minglian
Published: March 2022

Living in today’s world requires extensive communication with the world around us, which the mobile phone is one of this equipment along with other devices such as computers, radios, telephone towers, and power lines. It is supposed that prolonged exposure to radiation may cause biological damage to living organisms. However, the results from different laboratory studies are contradictory and there is still insufficient information about the biological risks to human health. In this article, we reviewed some of the potential biological effects of Radiofrequency Electromagnetic Field (RF-EMF) exposure.
Bioeconomy as A Way of Development and Sustainability: A Study Focused on the Field of Water
Authors: Belmonte-Urena L J , Batlles-delaFuente A , Abad-Segura E , Morales M E
Published: March 2022

The scarcity of natural resources as well as the increase in waste and environmental pollution are considered current challenges that must be solved. In this context in which the search for processes that ensure an improvement of the current situation prevails, the term bioeconomy arises. Said term, which is based on renewable biological resources as an alternative to fossil fuels, represents an advance in terms of sustainability. However, it is highly related to numerous sectors, such as fishing, agriculture, livestock, forestry and aquaculture, among others. In this sense, with the aim of limiting the implications and areas of interest for each of these sectors, the study focuses on analysing research trends in the field of bioeconomy and water resources. This is why the present work focuses on collecting the subject areas and keywords that define the current interests of this research line. Finally, the fundamental role of political actions to positively influence the introduction of new sustainable processes is mentioned.
Possibilities for Shifting Goods from Road to Rail Freight Transport in the Czech Republic
Authors: Cempirek Vaclav , Kodym Oldrich , Turek Michal
Published: March 2022

The paper deals with the change in the modal share of total freight transport. The aim is to reduce carbon emissions in freight transport to zero by 2030 and then by 2050 again, which will require a shift of freight transport from road to railway. As far as the Czech Republic is concerned, only land transport modes are substantial. The task will not be easy, as rail transport still has a share of about 30% of total transport. The change in transport policy is based on the EU Green Deal.
Kinetics of Nanoparticles Nucleation/Growth and Control of the Pt/C Catalysts Microstructure and Activity
Authors: Danilenko M. , Guterman V. , Paperzh K. , Alekseenko A. , Nikulin A.
Published: March 2022

A kinetic analysis of the complex Pt(IV) ions reduction has been carried out for two common liquid-phase synthesis methods, in which formaldehyde and formic acid are used as reducing agents. The character of the influence of temperature, the nature of the reducing agent and solution components, the atmosphere composition, and the carbon support have been established. This made it possible to optimize the synthesis conditions and obtain Pt/C catalysts with ultrasmall nanoparticles, significantly exceed commercial analogs in their morphology, durability, and activity in the oxygen electroreduction reaction.
Research on the wear and corrosion resistance of Ni–GO–TiC composite coating by scanning jet electrodeposition
Authors: Jiang Wei , Li Xiang , Chen Yuanlong , Li Huigui , Shen Lida , Chen Ya , Tian Zongjun , Lao YuanXia
Published: March 2022

The Ni–GO–TiC nano-composite coating was prepared by scanning jet electrodeposition. The morphologies and microstructures of the composite coating were analyzed by FESEM and XRD, and the wear and corrosion resistance of the composite coating were studied. Studies have shown that the Ni–GO–TiC composite coating has some ridge shape structures. The addition of nano TiC and GO does not change the structure but refines the grain growth of the Ni matrix metal. Nano TiC can effectively prevent GO from agglomerating, improve the dispersion, and further enhance the wear resistance of the Ni–GO–TiC composite coating. In addition, the microhardness and corrosion resistance of the Ni–GO–TiC composite coating has also been greatly improved. The hard nano TiC reinforcement proposed in this study helps to improve the comprehensive properties of nickel-based graphene oxide composite coatings, and provides a new method reference for subsequent research on nickel-based composite coatings.
The effect of laser power and scanning speed on forming structure in selective laser melting process
Authors: Huang Yao , Han Renheng , Zhang Hexin , Zhao Chengzhi
Published: March 2022

With the continuous development of ship technology, the usage environment of some parts has changed, with higher requirements for materials and preparation technology being put forward. Some traditional structural materials have do not meet the actual working conditions of ships, which necessitates development of new materials and research on their preparation technology. Owing to its high strength and stable mechanical properties at high temperature, molybdenum base alloy is expected to replace nickel base alloy and aluminum base alloy the primary structural material in the development of ships. Under the conventional method, the impurity elements is quite complex and there are limitations in the shape of the formed parts. This experiment uses spherical pure molybdenum powder as raw material. The effects of laser power, powder thickness, scanning speed and scanning distance on the microstructure of formed parts during selective laser melting process were studied and the optimum process parameters were determined. Laser power and scanning speed can seriously affect the quality of the forming parts. In this experiment, by comparing the density and internal holes of the forming parts under different process parameters, the best preparation process for the forming parts was determined: laser power 325 watts, scanning speed 400 mm s−1, powder thickness 30 μm, scanning distance 40 μm. Meanwhile, the forming workpiece density is the largest, up to 94.92%.
Effect of progressive solid-solution treatment on microstructures, mechanical properties and impact abrasive wear behavior of alloyed high manganese steel
Authors: Li Zulai , Wang Haibin , Zhao Yuelin , Wu Lei , Zhang Fei , Shan Quan
Published: March 2022

Alloyed high manganese steel is a general type of wear-resistant steel, and its precipitates and austenite matrix grain sizes play an important role in impact abrasive wear behavior. Solid-solution treatment is an effective method to balance the size of the austenite grains and precipitates. This work attempts to find a new progressive solid-solution treatment to make alloyed high manganese steel castings refine the microstructure and balance the wear resistance under impact abrasive wear conditions. Compared with traditional solid-solution treatment, the MC- and M23C6-type carbide precipitates resulting from progressive solid-solution treatment decrease, and the tensile strength and impact toughness of steel are significantly increased. After the solid-solution treatment at different heating rates, the grain refinement effect is remarkable after shortening the holding time at 1100 °C and increasing the heating rate to 150 °C h−1. The impact abrasive wear test results show that, compared with the traditional solid-solution treatment at 1100 °C for 4 h, the wear resistance of high manganese steel has a 23.1% improvement after progressive solution treatment at 1100 °C for 2 h, and the wear failure forms of all the experimental steels are microcutting, oxidation wear and plastic deformation.