bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk Factors for Neonatal Sepsis in Secondary and Tertiary Care Hospitals of a District in Sri Lanka: A Case–Control Study
Authors: Jayasinghe Chintha , Abeysena Chrishantha
Published: July 2021

Objective The aim of this study was to determine the risk factors for neonatal sepsis.

Methods A case–control study was performed in secondary and tertiary care hospitals of a district in Sri Lanka. Neonates who diagnosed with sepsis based on clinical criteria or culture positivity were taken as the case group (n = 240) and neonates born during the same period who had not been diagnosed with sepsis were taken as the control group (n = 240). The controls were recruited from the community. The study instruments were, pretested interviewer administered questionnaire, a check list and record sheets. Multiple logistic regression analysis was performed. The results were expressed as odds ratios (OR) with the 95% confidence intervals (CI).

Results The independent risk factors for neonatal sepsis were history of abortions, still birth, and early neonatal deaths (OR: 6.78; 95% CI: 3.2–14.3), registration of pregnancy after 8 weeks of gestation (OR: 1.91; 95% CI: 1.07–3.4), total antenatal clinic visits ≤4 (OR: 7.18; 95% CI: 2.1–24.5), history of maternal fever prior to the week of delivery (OR: 2.74; 95% CI: 1.25–6.0) leaking amniotic fluid >18 hours (OR: 10.0; 95% CI: 2.1–47.4), performed >3 vaginal examinations before delivery (OR: 3.28; 95% CI: 2.1–24.5), meconium stained amniotic fluid (OR: 10.57; 95% CI: 3.7–29.7), mode of delivery by cesarean section, forceps or vacuum (OR: 2.33; 95% CI: 1.4–3.9), time of birth of the neonate being during on-call hours (OR: 2.12; 95% CI: 1.3–3.5), being a male baby (OR: 1.74; 95% CI: 1.1–2.8), and birth weight <2,500 g (OR: 5.17; 95% CI: 2.8–9.6) of neonates.

Conclusion Most of the identified risk factors for neonatal sepsis were modifiable. Stringent implementation of guidelines and protocols would prevent neonatal sepsis.
The Merits of the External Rhinoplasty
Authors: Gantous Andres , Ziai Hedyeh
Published: July 2021

The authors present their views on the merits of external rhinoplasty in the context of a renewed awareness of the endonasal approach. Why do we continue to perform rhinoplasty via an open approach? The benefits of this technique such as its unparalleled exposure, the opportunity for technical precision, and the ability to better preserve nasal function are thoroughly explored. The criticisms of this technique are presented and discussed. The authors thoughts on rhinoplasty as a whole are examined.
Study of Bone Marrow Lymphocyte Subset in Acute Myeloid Leukemia
Authors: Dange Prasad , Tyagi Seema , Juneja Richa , Seth Tulika , Saxena Renu
Published: July 2021

Introduction Acute myeloid leukemia (AML) is a heterogenous disorder consisting of clonal expansion of myeloblasts. Tumor immunity plays an important part in the pathobiology of AML. Understanding the components of tumor immunity is important for understanding tumor pathogenesis and the principles of immunotherapy.

Methods We studied 41 patients with AML, for total lymphocyte, CD4 positive helper T cells, CD8 positive cytotoxic T cells, and CD16/56 positive natural killer (NK) cells proportion. Quantification was done on bone marrow aspirate sample by flowcytometry. Whenever available, post induction bone marrow was also analyzed for the lymphocyte subset.

Results No significant difference was noted in the percentage of blasts among the three risk categories: favorable, intermediate, and adverse. However, there was significant difference in the total lymphocyte among the risk stratification groups, being highest in the favorable group and lowest in the adverse group. CD8 positive cytotoxic T cells were significantly less in Acute Promyelocytic Leukemia (APML) cases (p = 0.001). Total lymphocytes were, however, more numerous in APML (p = 0.005). NK cell proportion was not significantly different between APML and non-APML patients.

On completion of induction chemotherapy, bone marrow samples for 12 patients could be processed for lymphocyte subset. On comparing the baseline against the post induction bone marrow, it was observed that there was significant increment in the proportion of CD4 positive T lymphocytes (p = 0.046).

Conclusion There is a difference in lymphocyte subset amongst patients with AML. Larger studies including functional aspects are needed to better define the role of lymphocytes in disease pathogenesis.
Investigation and optimization of N-polar GaN porosification for regrowth of smooth hillocks-free GaN films
Authors: Collins Henry , Sayed Islam , Liu Wenjian , Pasayat Shubhra S. , Taylor Aidan A. , Li Weiyi , Keller Stacia , Mishra U. K.
Published: July 2021

This work investigates the process of planar electrochemical etching of pores in n-type nitrogen-polar GaN and the effect of pore morphology on regrown GaN film surface quality. An increase in the anodization voltage was found to increase the pore diameter and reduce the density of pores with inclined sidewalls near the surface of the porosified films. Simultaneously, a decrease in the hexagonal hillock size and number following GaN regrowth was observed. It is proposed that vertical pore sidewalls are essential to demonstrate high quality film coalescence. For smooth hillock-free 100 nm GaN regrowth, an optimal bias of 17 and 13 V for Ti-contacted N-polar GaN:Si with a Si doping of 4.5 × 1018 and 8 × 1018 cm−3, respectively, was found.
Enhancement and manipulation of the thermoelectric properties of n-type argyrodite Ag8SnSe6 with ultralow thermal conductivity by controlling the carrier concentration through Ta doping
Authors: Namiki Hiromasa , Yahisa Daisuke , Kobayashi Masahiro , Shono Atsushi , Hayashi Hideo
Published: July 2021

N-type argyrodite Ag8SnSe6 shows great potential as a novel thermoelectric material from room to middle temperatures. However, its thermoelectric properties cannot be manipulated because of the difficulty in controlling the carrier concentration by electron doping. In this study, to discover a suitable dopant for controlling the carrier concentration, we used Ta5+, Mo6+, and W6+ as dopants for Sn4+ in n-type Ag8SnSe6. Only Ta-doped Ag8SnSe6 was obtained as a single phase, and the thermoelectric properties relevant to the carrier concentration of n-type Ag8Sn1−xTaxSe6 (0.0 ≤ x ≤ 0.05) were experimentally investigated. The lattice thermal conductivities were ultralow (around 0.5 W m−1 K−1) and showed glass-like behavior independent of the temperature. The carrier concentration monotonically increased with increasing x. The power factor and dimensionless figure of merit ZT were related to the value of x, and they showed dome-like behavior as a function of x. The power factors of Ag8Sn1−xTaxSe6 in the orthorhombic phase at 300 K and superionic phase at 390 K reached ∼5.3 µW cm−1 K−2 for x = 0.0375 and ∼4.6 µW cm−1 K−2 for x = 0.05, respectively. The ZT values of ∼0.28 for x = 0.025 in the orthorhombic phase at 300 K and ∼0.51 for x = 0.0375 in the superionic phase at 390 K were ∼40% and ∼220% higher than those of non-doped Ag8SnSe6. Therefore, Ta doping of Ag8SnSe6 can control the carrier concentration and result in enhancement and manipulation of the thermoelectric properties.
The characterization of particle number and distribution inside in-flight 3D printed droplets using a high speed droplet imaging system
Authors: Chen Xinxing , O’Mahony Aidan P. , Barber Tracie
Published: July 2021

3D bioprinting is an innovative and time-saving method to precisely generate cell-laden 3D structures for clinical and research applications. Ejected cell number and cell distribution are two key technical parameters for evaluation of the bioprinter performance. In this paper, a modified droplet imaging system is used to study cell-size fluorescent particle number and distribution within droplets ejected from a microvalve-based 3D bioprinter. The effects of droplet dispensing physics (dosing energy Ed), ink properties (Z number—the inverse of the Ohnesorge number and particle sedimentation velocity), and input particle concentration are considered. The droplet imaging system demonstrates a strong capability in analyzing bioprinting performance for seeded concentrations less than 3×106 particles/ml. The printed particle number increases near-linearly under increasing dosing energy and Z number. It was found that for 7<Z<21 and seeded particle concentration no less than 3×106 particles/ml, particles within the visualized droplets approached a homogeneous distribution in the 2D images. It was also determined that the particle sedimentation velocity within the ink has a positive relationship to the ejected particle number over time—with the particle distribution approaching a homogeneous state over increasing sedimentation time.
Clinical evidence that a dysregulated master neural network modulator may aid in diagnosing schizophrenia
Authors: Nomoto Munetaka , Konopaske Glenn T. , Yamashita Naoya , Aoki Reina , Jitsuki-Takahashi Aoi , Nakamura Haruko , Makihara Hiroko , Saito Mari , Saigusa Yusuke , Nakamura Fumio , Watanabe Keisuke , Baba Toshihiko , Benes Francine M. , Tobe Brian T. D. , Pernia Cameron D. , Coyle Joseph T. , Sidman Richard L. , Hirayasu Yoshio , Snyder Evan Y. , Goshima Yoshio
Published: July 2021

Significance

There are no biomarkers for schizophrenia (SCZ), a disorder of dysfunctional neural networks. We demonstrate that a master regulator of cytoskeleton (“CRMP2”) and, hence, neural circuitry, may form the basis for such a biomarker because its activity is uniquely imbalanced in SCZ patients. We show that SCZ patients are characterized by an excess of active CRMP2 not only in their brains (where it is correlated with dendritic abnormalities) but also in their peripheral blood lymphocytes. The abundance of active CRMP2 and insufficiency of opposing inactive p-CRMP2 likely disrupts neuronal function. Because peripheral blood CRMP2 appears to reflect intracerebral processes, it could form the basis of a rapid, minimally invasive, sensitive, and specific clinical diagnostic aid for SCZ in young patients.
A functional mammalian display screen identifies rare antibodies that stimulate NK cell–mediated cytotoxicity
Authors: Kang Emily , Kadoch Cigall , Rubenstein James L. , Lanier Lewis L. , Wells James A.
Published: July 2021

Significance

We have developed a method to screen for antibodies that can induce natural killer (NK) cell–mediated cytotoxicity. NK cells have the innate ability to identify and kill target cells. Antibodies that bind to NK cell surface proteins are anchored to the cell surface of a target cell line and probed for their abilities to stimulate NK cytotoxicity. Target cells displaying antibodies that induce NK cell–mediated cytotoxicity are depleted from the antibody pool. Because the antibodies are based on the same scaffold, antibodies on surviving target cells can be identified through next generation sequencing of complementarity determining region H3. This method facilitates the identification of antibodies that can stimulate immune cell activation and may be used to desig immunotherapies.
Functional behaviour of TiNi shape memory alloy after high strain rate deformation
Authors: Ostropiko Eugeny , Yu Konstantinov Alexandr
Published: July 2021

This paper presents an investigation of the influence of strain rate on the functional behaviour of TiNi alloy. Specimens were deformed in compression and tension modes using the Kolsky method for a split Hopkinson pressure bar, and its modification in martensitic, austenitic, and pre-martensitic states at 500, 1000, and 1500 s−1 strain rates. One-way shape memory and two-way shape memory (TWSM) effects were measured and compared with ones after quasi-static deformation. With an increase in the strain rate, the one-way shape memory effect decreased, but the TWSM effect increased. Functional behaviour indirectly demonstrated the sensitivity of the martensite reorientation and the formation of stress-induced martensite to strain rate. Strain rate sensitivity led to differences in the shape recovery curves during thermocycling.
Anisotropic expansion of hepatocyte lumina enforced by apical bulkheads
Authors: Belicova Lenka , Repnik Urska , Delpierre Julien , Gralinska Elzbieta , Seifert Sarah , Valenzuela José Ignacio , Morales-Navarrete Hernán Andrés , Franke Christian , Räägel Helin , Shcherbinina Evgeniya , Prikazchikova Tatiana , Koteliansky Victor , Vingron Martin , Kalaidzidis Yannis L. , Zatsepin Timofei , Zerial Marino
Published: July 2021

Lumen morphogenesis results from the interplay between molecular pathways and mechanical forces. In several organs, epithelial cells share their apical surfaces to form a tubular lumen. In the liver, however, hepatocytes share the apical surface only between adjacent cells and form narrow lumina that grow anisotropically, generating a 3D network of bile canaliculi (BC). Here, by studying lumenogenesis in differentiating mouse hepatoblasts in vitro, we discovered that adjacent hepatocytes assemble a pattern of specific extensions of the apical membrane traversing the lumen and ensuring its anisotropic expansion. These previously unrecognized structures form a pattern, reminiscent of the bulkheads of boats, also present in the developing and adult liver. Silencing of Rab35 resulted in loss of apical bulkheads and lumen anisotropy, leading to cyst formation. Strikingly, we could reengineer hepatocyte polarity in embryonic liver tissue, converting BC into epithelial tubes. Our results suggest that apical bulkheads are cell-intrinsic anisotropic mechanical elements that determine the elongation of BC during liver tissue morphogenesis.
Impact of the laser spatio-temporal shape on Breit–Wheeler pair production
Authors: Mercuri-Baron A , Grech M , Niel F , Grassi A , Lobet M , Di Piazza A , Riconda C
Published: July 2021

The forthcoming generation of multi-petawatt lasers opens the way to abundant pair production by the nonlinear Breit–Wheeler process, i.e. the decay of a photon into an electron–positron pair inside an intense laser field. In this paper we explore the optimal conditions for Breit–Wheeler pair production in the head-on collision of a laser pulse with gamma photons. The role of the laser peak intensity versus the focal spot size and shape is examined keeping a constant laser energy to match experimental constraints. A simple model for the soft-shower case, where most pairs originate from the decay of the initial gamma photons, is derived. This approach provides us with a semi-analytical model for more complex situations involving either Gaussian or Laguerre–Gauss (LG) laser beams. We then explore the influence of the order of the LG beams on pair creation. Finally we obtain the result that, above a given threshold, a larger spot size (or a higher order in the case of LG laser beams) is more favorable than a higher peak intensity. Our results match very well with three-dimensional particle-in-cell simulations and can be used to guide upcoming experimental campaigns.
Alternative non-Gaussianity measures for quantum states based on quantum fidelity
Authors: Xiang Cheng , Li Shan-Shan , Wen Sha-Sha , Xiang Shao-Hua
Published: July 2021

We propose three alternative measures for non-Gaussianity of quantum states: sine distance, Bures angle, and Bures distance, which are based on quantum fidelity introduced by Wang [Phys. Lett. A
373 58 (2008)]. Using them, we evaluate the non-Gaussianity of some relevant single-mode and two-mode non-Gaussian states and find a good consistency of the three examined measures. In addition, we show that such metrics can exactly quantify the degree of Gaussianity of even Schrödinger-cat-like states of small amplitudes that can not be measured by other known non-Gaussianity measures such as the Hilbert–Schmidt metric and the relative entropy metric. We make a comparative study between all existing non-Gaussianity measures according to the metric axioms and point out that the sine distance is the best candidate among them.
Mechanism analysis and improved model for stick-slip friction behavior considering stress distribution variation of interface
Authors: Han Jingyu , Ding Jiahao , Wu Hongyu , Yan Shaoze
Published: July 2021

Studying the evolution of interface contact state, revealing the “black box” behavior in interface friction and establishing a more accurate friction model are of great significance to improve the prediction accuracy of mechanical system performance. Based on the principle of total reflection, a visual analysis technology of interface contact behavior is proposed. Considering the dynamic variation of stress distribution in interface contact, we analyze the nonlinear characteristics of contact parameters in different stages of stick-slip process using the above-mentioned experimental technology. Then, we find that the tangential stiffness of the interface is not a fixed value during the stick-slip process and the stress distribution variation is one of the important factors affecting the tangential stiffness of interface. Based on the previous experimental results, we present an improved stick-slip friction model, considering the change of tangential stiffness and friction coefficient caused by the stress distribution variation. This improved model can characterize the variation characteristics of contact parameters in different stages of stick-slip process, whose simulation results are in good agreement with the experimental data. This research may be valuable for improving the prediction accuracy of mechanical system performance.
Tunneling STM/STS and break-junction spectroscopy of the Pb-doped Bi2223 superconductor
Authors: Sugimoto Akira , Ohtsubo Hironori , Matsumoto Kaito , Ishimitsu Satoru , Iwano Masatoshi , Ekino Toshikazu , Gabovich A M
Published: July 2021

The combined scanning tunneling microscopy/spectroscopy (STM/STS) and the break-junction tunneling spectroscopy (BJTS) measurements of the three-layered Pb
x
Bi2-x
Sr2Ca2Cu3O10+y cuprate superconductors were carried out. The averaged dI/dV spectrum obtained by the STS shows the gap Δ
STS
≈ 45 meV, while that of BJTS shows Δ
BJ
≈ 35 meV. In case of the BJTS measurements, we also referred the zero bias (ZB) peak as being due to the maximum Josephson current IJc
. The product of IJc
and normal resistance RN
(IJcRN
) was obtained IJcRN
≈ 3.5 mV at T = 11 K, which is one order lower than that of the BCS-based Ambegaokar-Baratoff theory with Δ
BJ
=35 meV taken into account. With increasing the temperature, the IJcRN
was reduced and vanished just below the Tc
(≈ 106 K), indicating the bulk superconductivity. Simultaneously, from the temperature dependence of the gap features from 80 K to 120 K, the gap Δ was shown to persist across the Tc
, indicating that the IJcRN
product is a significant parameter for understanding the cuprate superconductivity.
Influence of long-term exposure of high-density direct current on the current carrying ability of 2G HTSC tapes based on the REBCO
Authors: Veselova Svetlana , Osipov Maxim , Starikovskii Alexandr , Anishenko Irina , Pokrovskii Sergey , Abin Dmitriy , Rudnev Igor
Published: July 2021

In this work, the phenomena of electromigration in samples of HTSC tapes of the 2nd generation was investigated. Samples of REBa2Cu3O7-x (REBCO, where RE is a rare earth element) were used in the form of a copper-plated tape. A superconducting bridge was preliminarily formed on the surface of the tape by the method of chemical etching (to decrease the total value of critical current). The sample was exposed by a direct current of I = 0.9Ic
. The duration of exposure was up to 350 hours. The value of the current density in the area of the bridge was J = 1.38×1010A/m2. The measurements were carried out at liquid nitrogen temperature (77 K). The influence of the electric current flow on the value of the sample critical current is controlled at the selected time intervals. The experiment showed high stability of the tape under the specified conditions.
Preparation of Y
x
Yb1-x
Ba2Cu3O7-δ
bulks for superconducting joint between REBCO-coated conductors
Authors: Mun Ka Kei , Murakami Tomoya , Kanazawa Shintetsu , Momono Naoki
Published: July 2021

In this study we prepared Y
x
Yb1-x
Ba2Cu3O7-δ
(x = 0.1, 0.2, 0.3, 0.4, 0.5) powders and bulks to use as intermedium for superconducting joint between REBCO-coated conductors. Superconducting joints are essential in the development of high-field REBCO persistent magnets. All the powders and bulks were sintered at 850 °C for 10 hours in air. Bulks were prepared by pressing at 70 MPa. Calcination of the bulks was performed under the same conditions as the powders. Two joint samples between GdBa2Cu3O7-δ
-coated conductors were prepared by using the bulk samples. For x=0.1, a superconducting joint was successfully obtained.
Development of Superconducting Coils using (Ba, Na)Fe2As2 Round Wires with Large Critical Current
Authors: Pyon S , Mori H , Tamegai T , Kajitani H , Koizumi N , Awaji S , Kito H , Ishida S , Yoshida Y
Published: July 2021

We report the fabrication of 10 m-class (Ba, Na)Fe2As2 long round wires and coils using these round wires. Round wires are fabricated by powder-in-tube (PIT) method and hot-isostatic-press (HIP) technique. To increase Ic
keeping the diameter of the wire constant, the cross section area of the superconducting core is enlarged by changing the dimensions of metal sheaths. At 4.2 K under a high field of 100 kOe, Jc
of a short segment of HIP wire reaches 42 kAcm-2, which is comparable to the highest Jc
of IBS round wires of 44 kAcm-2. Furthermore, Ic
of the HIP wire at 4.2 K under 10 kOe and 100 kOe reaches 95 A and 54 A, respectively, which is about twice the value of the previous report. We also fabricated a small demonstration superconducting coil using 12.5 m long PIT wires by HIP method. Ic
of the whole coil is ∼60 A under the self-field, and magnetic field at the center of the coil reaches 2.6 kOe. The coil generated the magnetic field of 43 Oe/A, which is almost consistent with the calculated field from the coil dimensions.
A Timing Fault Model and an Efficient Timing Fault Simulation Method for Rapid Single-Flux-Quantum Logic Circuits
Authors: Nakamura Shogo , Takagi Kazuyoshi , Kito Nobutaka , Takagi Naofumi
Published: July 2021

We examine digital behavior of faults caused by a change of the order of the pulse arrivals in Rapid Single-Flux-Quantum (RSFQ) logic circuits. Based on the timing fault model, we present a flow of automatic test pattern generation for testing digital RSFQ chips. As the test pattern generation repeatedly executes fault simulation, the scalability depends on computational cost of the simulation. We propose an efficient fault simulation method based on two ideas. First, we share computation for the fault-free circuit and faulty circuits as much as possible. Secondly, we exploit the pipelined behavior of RSFQ logic circuits to suppress computation for unnecessary signals. We have implemented our simulation method and obtained evaluation results to show that our method is effective for large circuits.
Energy Extraction Performance of Tandem Ground-effect Hydrofoils
Authors: Yang Hao , He Guanghua , Mo Weijie , Wang Wei
Published: July 2021

To study the influence of the spatial configuration of two tandem ground-effect hydrofoils on the power-extraction efficiency, this paper uses the overset grid method to establish a two-dimensional numerical calculation model based on the STAR-CCM+ software. The comparison of the numerical results of the single hydrofoil verifies the validity of the method. This paper systematically analyzes the influence of ground effect on the energy extraction performance of the hydrofoil, and further studies the changes in the hydrodynamic performance and energy extraction efficiency of the hydrofoil when two ground effect hydrofoil are tandem. The results show that: compared with a single ordinary hydrofoil, the energy extraction efficiency of the ground-effect hydrofoil is slightly improved. When the hydrofoil is close to the wall, its lift will be significantly increased due to ground effect. When two ground effect hydrofoils are tandem with a phase difference of 180 deg, the vortex generated by the upstream hydrofoil will significantly increase the absolute lift of the downstream hydrofoil, but the energy extraction efficiency will be reduced significantly.
Research on Surveying Technology of Special-shaped Immersed Tube Installation in Hong Kong NSL Tunnel
Authors: Chong-ming Wang , Wanghui Li , Hanbin Zhong
Published: July 2021

The advantages of immersed tunnel are shallow depth and large cross-section. Victoria Bay is spanned by the NSL tunnel in Hong Kong. Kowloon and Hong Kong Island are connected. The tunnel consists 11 immersed tubes. Based on the study of the establishment of the coordinate system of special-shaped tube joints, the establishment and calibration of attitude surveying system, and the calibration of RTK-GPS, a set of surveying system for the installation and joint of special-shaped immersed tubes is developed to solve the problem in the construction of NSL tunnel. The installation of the E10 is guided. Compared with the traditional total station survey method, the installation and joint surveying system can meet the accuracy requirements and can be extended to similar immersed tunnel projects in the future.
The Spatial Variation Characteristics and Mechanism of Landing Tropical Cyclones in China
Authors: Li Bei , Gu Chenglin , Zhang Wenwen
Published: July 2021

Based on the tropical cyclone (TC) data from the United States Joint Typhoon Center, this paper analyzes the spatial variation characteristics and possible mechanism of the TC that landed in China during the 65 years from 1951 to 2015. The conclusions are as follows. (1) The TC transformation location moves to southeast in El Niño years, and shifts to northeast in La Niña years. (2) In El Niño years, the frequency of TC affecting the coast of Mainland China is relatively low, while the frequency of TCs affecting Japan is increasing. In La Niña years, the frequency of TCs affecting Japan and the surrounding waters, the Yellow Sea, the Bohai Sea and the South China Sea increased, while that of Taiwan province decreased. (3) The changes in the local circulation in the Northwest Pacific increased the sea temperature, increased convection, increased relative humidity in the middle layer, weakened vertical wind shear, increased low-level vorticity, and increased high-level divergence in the southeastern part of the Northwest Pacific during the El Niño year. The large-scale circulation adjustments provided favorable background conditions for the southeast movement of the TC generating position. The southeast movement of the spawning location makes the landing TC activities have a longer moving distance and thus increases the life history. In La Niña years, the subtropical high weakened and moved eastward. This environment is conducive to generating more TCs to land in China in the La Niña year.
Ecosystem Pushing: Coral Restoration in Refugia as an Unexplored Answer to Climate Change Adaptation
Authors: Mertz Edith Maria , McDonald Anne
Published: July 2021

Climate change is driving ecosystem change across the biosphere on an unprecedented scale. Large biogeographic shifts are underway as habitats move their ranges towards the poles in an attempt to remain in zones that adhere to organisms’ preferred temperature ranges. These new areas of shifting climatic ranges, or refugia, represent important opportunities for the future survival of countless species in a warming world. However, many species may have colonisation rates too slow to keep up with climate change. This may be due to barriers to dispersal, long time periods in reproductive cycles, survival and viability of offspring, geographic isolation of suitable new habitats, stochasticity and other environmental factors. Ecosystem pushing proposes to propagate species into refugia using restoration techniques with the aim of supporting species survival and ecosystem conservation. This paper proposes ecosystem pushing as a new management intervention for the field of coral reef restoration. Management considerations will need to include geographic models of refugia projections to ascertain appropriate locations for restoration work. Other important considerations would include assessing the risks of losing one ecosystem type for another, invasive species and disease introductions, issues of intervention scale and time constraints, and levels of stakeholder engagement with local communities.
A Study on Comprehensive Evaluation of Multiple-depth Sea Water Quality in the South China Sea
Authors: Ma Xiaolei , Duan Mengshan , Duan Duomo , Qiu Jinquan , Cao Junrui
Published: July 2021

During the investigation in the South China Sea in the summer of 2018, the sea water samples were for temperature, salinity, dissolved oxygen, pH, nutrient salts (NO3-N, NO2-N, NH4-N, PO4-P, SiO3-Si), essential elements (Na, K, Mg, Ca, Sr, Cl, Br, B), trace elements (Cu, Zn, Fe Mn, Ni, Se, Mo, Co and V), heavy metal (Hg, Pb, As, Cd), organic elements (TOC, DOC, GOC), chlorophyll and microorganisms analyses from different layers of 12 stations according to the standard sampling specifications. The seawater samples of different depths were directly measured by inductively coupled plasma mass spectrometry. The distribution of several elements in the South China Sea water was investigated. It could be seen from the analytical results that the water temperature, salinity, pH, dissolved oxygen, the content of NO3-N, PO4-P, SiO3-Si, K+, Mg2+, Ca2+, Sr2+, Cl-, Br-, B3+, Zn, Mn, V, Cr, GOC and Chlorophyll was significantly correlated with depth of seawater.
Spatial and Temporal Variation Characteristics of Northwest Pacific Tropical Cyclone Activity in Global Warming Scenario
Authors: Guo Xinyu , Gu Chenglin , Li Bei , Zhang Wenwen
Published: July 2021

Utilizing the Joint Typhoon Warning Center (JTWC) TC best-track data covering the period of 1951-2015, spatial and temporal variation characteristics of Northwest Pacific tropical cyclone activity in global warming scenario is discussed. The annual frequency trend of TC in the Northwest Pacific is as follows: from the late 1950s to the early 1960s, there was an obvious upward trend, the late 1960s to the early 1980s showed a downward trend, the late 1980s to the mid 1990s showed an upward trend, and the mid-1990s to the late 2010s showed a downward trend. The frequency of super TY in the Northwest Pacific showed a rapid downward trend from the late 1960s to the early 1980s, and then changed to a slow upward trend. The region where the linear change of different stages of TC life cycle stage (genesis, development, mature, decay) frequency is approaching to central Asian coastline. Northwest Pacific TC activity decreases, but from the perspective of spatial distribution of linear changes, the threat of TC towards eastern Asia is enhanced. That is probably because the global warming scenario results in the increasing temperature gradient between Northwest Pacific and central and eastern Pacific, which leads to the strengthening of walker circulation. The strengthening walk circulation could increase the magnitude of the vertical wind sheer and the relative vorticity on the tropical Northwest Pacific, which affects the spatial variation of TC activity in Northwest Pacific.
Geomorphologic Impact of Construction of Breakwaters at Ponnani Fishery Harbour in Kerala
Authors: Paravath Kunhimammu , Parth Jhoga , Nasar T
Published: July 2021

Coast belonging to one particular stretch happens to be versatile because of its dynamicity. This dynamicity is attributed to both natural and anthropogenic activities. Hence, it is important to monitor any fragile coastal stretch’s dynamicity in a temporal basis. In the present study, an attempt is made to analyse the shoreline changes using Digital Shoreline Analysis System (DSAS), by calculating Linear Regression Rate (LRR), in response to the construction of two breakwaters at Ponnani which is a major fish landing centre in Malappuram district of Kerala state in India. Shorelines were extracted from field data, satellite imageries, LANDSAT (1979-2002) and Google earth (2010-2016). From the detailed analyses, before the construction of breakwaters, it is inferred that erosion at the rate of 1.5m/yr and 5.3m/yr was observed on north and south sides of Ponnani estuary respectively. But after construction, an accretion at the rate of 3m/yr on either side of estuary is observed.
The Optimize of Tug Configuration Based on Fuzzy Comprehensive Evaluation and Entropy Weight Analysis
Authors: Jiang Fucai , Han Zhang , Quandang Ma
Published: July 2021

As ships increasingly become larger, the corresponding port facilities can’t meet the requirements of arriving ships. This paper will use fuzzy comprehensive evaluation and analytic hierarchy process to propose an optimization plan for the configuration of port tugboats. In order to obtain the optimal tugboat configuration plan, entropy weight method is introduced in the weight analysis of the original fuzzy comprehensive evaluation to confirm the weight of evaluation factors. The problem of partial subjectivity in the determination of factor weights in the existing fuzzy synthesis method is improved. The tugboat configuration proposed at the end of this article is consistent with the existing Qingdao Port tugboat configuration mode.
Efficiency Evaluation of Major Coastal Ports in China: Application of the Three-stage DEA Model
Authors: Zhang Xinfang , Lu Jing , Peng Yan
Published: July 2021

With the increasing competition between ports, how to improve port efficiency and promote the sustainable development of ports becomes the focus of attention. The paper applies the three-stage data envelopment analysis (T-S DEA) model to measure the efficiency of top 10 Chinese coastal ports, including the scale efficiency (SE) and technical efficiency (TE). Besides, the principle component analysis approach is adopted to reduce the influence of redundant information of evaluation indicators on results. The stochastic frontier analysis regression model is applied to eliminate the effects of environmental factors and stochastic errors under similar exterior conditions. The results show: (1) The ports efficiency (SE and TE) in different regions is quite different; the efficiency of Chinese coastal ports is generally low, which is mainly caused by scale inefficiency; (2) The SE and TE are improved and the input and output redundancy ratio are decreased significantly by comparing the results of traditional DEA model. (3) Shanghai, Ningbo-Zhoushan, Shenzhen, Hong Kong and Kaohsiung have relatively high comprehensive efficiency. This study provides valuable information for estimating port efficiency and establishing competitive strategies in the future.
Application of Mechanical Relations in Mathematical Modeling to Oxygenate Synthetic Wastewater through a Circular Rotary Aerator
Authors: Jose Vladimir Cornejo Tueros , Elias Adrian Sanabria Perez , Adrian Elias , Danitza Mayli Cuñivo Muñico , Pascual Victor Guevara Yanqui , del Pilar Huanca Villanes Yanett
Published: July 2021

This paper expounds the issue about the evolution of the dissolved oxygen concentration in synthetic wastewater with a circular rotary by setting a mathematical model. The mathematical model is based on the Lewis and Whitman relations to transfer oxygen to water, and includes the mechanistic models proposed by Lee, to determine the global oxygen transfer coefficient and the oxygen saturation concentration in water, as a function of the fifth power temperature. For this purpose, historical data from aeration experiments with two types of discs and two levels of COD concentration were compared. The equation allows to include the effect of the variation of the temperature and atmospheric pressure. Finally, through the data obtained, it’s concluded that the estimation error is not affected by the type of disc, the COD concentration of the synthetic wastewater or by the interaction of both, and is less than + - 0.086 mg / L dissolved oxygen.
Techno-Financial comparison between photovoltaic systems with bifacial and monofacial technology in the location of Naco and Marcovia, Honduras
Authors: Núñez C , Reyes Duke A M
Published: July 2021

Technology is constantly growing, however, in the same way energy demand; over the years, different ways have been sought to better use of renewable resources in order to achieve better results in energy generation and supply that energy demand, but in turn to be feasible methods, an example of this is bifacial photovoltaic systems. This research carried out a Techno-Financial comparison between bifacial and monofacial systems for the locations of Naco, Cortés and Marcovia, Choluteca. In which the design of a bifacial photovoltaic installation was carried out assuming three types of land, being grass, soil and white gravel, with the purpose of analyzing the increase in albedo, and consequently the increase in energy production. Similarly, a monofacial system was designed for the same locations with the same capacity. The research made use of a quantitative methodology with a correlational focus, in which LCOE was established as the main research variable. In this way it was determined which photovoltaic system of those analyzed presents the lowest LCOE for both locations, of which it was made based on two assumptions, considering the value of the terrain and without considering it. Finally it was possible to determine that the lowest LCOE in a scenario where the value of the terrain is considered is obtained by the monofacial system for both localities, otherwise the scenario without considering the value of the terrain, the lowest LCOE presented by the bifacial system.
Characters of Different Materials as Supercapacitor Electrodes
Authors: Song Ziqing
Published: July 2021

As a new type of energy storage device between traditional capacitors and batteries, supercapacitors have the properties of fast charging and discharging of capacitors, as well as the energy storage characteristics of batteries. With the deterioration of the global climate and the reduction of resources, supercapacitors have received widespread attention. Electrode materials take an important part of ultracapacitors, which affect the performance and production of ultracapacitors. This paper studies the effects of different preparation methods and different dopants on the performance of activated carbon electrodes. The purpose of this article is to summarize the methods and research directions for improving the performance of activated carbon electrodes. Through the summary, it can be found that the specific capacity, internal resistance and cycle life of the activated carbon electrode are greatly improved by forming the composite electrode material of the metal compound or polymer and activated carbon. But whether it can be put into mass production has also become one of the factors to be considered in future research.
Conformal screen printed graphene 4 × 4 wideband MIMO antenna on flexible substrate for 5G communication and IoT applications
Authors: Zhou Xinyao , Leng Ting , Pan Kewen , Abdalla Mahmoud , Novoselov Kostya S , Hu Zhirun
Published: July 2021

Screen-printed graphene is integrated with multiple-input multiple-output (MIMO) technology to conquer the most concerned surge in electronic waste caused by the mass deployment of Internet of things (IoT) applications. A flexible MIMO antenna is implemented with simple fabrication process suitable for large-scale production by screen printing graphene highly conductive ink on paper substrate, ensuring high-speed 5G mass data wireless transmission without damaging the ecological environment. This environmental-friendly, low-cost, flexible and conformal MIMO antenna with orthogonal polarization diversity employs co-planar waveguide feed and planar pattern for achieving high space utilization and better integration in most scenarios, for instance, body centric networks and monitoring systems. Excellent performance has been achieved due to the high conductivity of the graphene: the fabricated antenna exhibits an average sheet resistance of

1.9

Ω

s

q

−
1

. The bandwidth of the antenna ranges from

2.22

 GHz to 

3.85

 GHz

(53.71% fractional bandwidth), covering

4

G

long term evolution, sub-6 GHz

5

G

mobile communication networks, 2.5 and 3.5 GHz WiMAX, and 2.4 and 3.6 GHz WLAN. Within this range, the antenna exhibits effective radiation, also its envelope correlation coefficient remains below

0.2
×

10

−
6

, manifesting outstanding signal transmission quality in a variety of wireless networks. This work illustrates a novel aggregation of MIMO technology and graphene printing electronics, enabling cheap accessible and green MIMO antennas to be massively integrated in IoT applications.
A combinatorial study of electrochemical anion intercalation into graphite
Authors: Chugh Manjusha , Jain Mitisha , Wang Gang , Nia Ali Shaygan , Mirhosseini Hossein , Kühne Thomas D
Published: July 2021

Dual-ion batteries are considered to be an emerging viable energy storage technology owing to their safety, high power capability, low cost, and scalability. Intercalation of anions into a graphite positive electrode provides high operating voltage and improved energy density to such dual-ion batteries. In this work, we have performed a combinatorial study of graphite intercalation compounds considering four anions, namely hexafluorophosphate (PF

6

−

), perchlorate (ClO

4

−

), bis(fluorosulfonyl)imide (FSI−), and bis(trifluoromethanesulfonyl)imide (TFSI−), via first-principles calculations. The structural properties and energetics of the intercalation compounds are compared based on different sizes, geometries, and the physical and chemical properties of the intercalated anions. The staging mechanism of anion intercalation into graphite and the specific capacities, and voltage profiles of the intercalated compounds are investigated. A comparison regarding battery electrochemistry is also done with available experimental observations. Our calculated intercalation energies and voltage profiles show that the initial anion intercalation into graphite is less favorable than subsequent ones for all the anions considered in this study. Although the effect of the size of anions in a graphite cathode on various properties of the intercalated compounds is not as significant as the size of cations in a graphite anode, some distinction between the studied anions can still be made. Among the studied anions, the intercalation compounds based on PF

6

−

are the most stable ones. These PF

6

−

anions cause relatively small structural deformations of the graphite and have the highest oxidative ability, highest onset voltage, and highest diffusion barrier along the graphene sheets. The overall small diffusion barriers of the anions within graphite explain the high rate capability of dual-ion batteries.
Comparative study on the strain-dependent mechanical and electronic properties of Nb3Al and Nb3Sn
Authors: Liu Zhao , Wang Biao
Published: July 2021

Nb3Al and Nb3Sn are important A15 compounds due to their good superconducting properties in high magnetic field. The strain coming from multiple sources would result in the degradation of superconducting performance for both of them. Extensive experimental studies have found that Nb3Sn has higher strain sensitivity than Nb3Al. However, most of the previous theoretical works focus on the effect of compressive hydrostatic pressure, which doesn’t reflect the actual working condition. In this work, first-principles calculations were done to investigate the mechanical behaviors of the two materials under the three crystallographic uniaxial tensile loadings. Determined from the stress-strain relations, the theoretical strength of Nb3Al is found to be slightly higher than that of Nb3Sn, which is validated by the energy-strain curve and the corresponding phonon instability. Electronic analyses show that the property difference of the two materials is attributed to their different bonding states and strain sensitivities. The present work unveils why the superconductivity of Nb3Sn is more sensitive to strain than Nb3Al on the microscopic level.
Muon study hints at new physics
Authors: Cartlidge Edwin
Published: July 2021

A measurement of the muon’s magnetic moment is at odds with the Standard Model – potentially hinting at new forces or particles – as Edwin Cartlidge reports
Rocky ‘super Earth’ offers best chance yet for atmospheric studies
Authors: Jarman Sam
Published: July 2021

A newly discovered exoplanet called Gliese 486b could be the best opportunity yet to study the atmosphere of a terrestrial planet beyond the solar system
Black hole magnetic field lines revealed in new Event Horizon Telescope image
Authors: Johnston Hamish
Published: July 2021

Scientists working on the Event Horizon Telescope (EHT) have released a new image showing the magnetic fields surrounding the supermassive black hole M87*.
CERN announces hints of ‘leptoquark’ particle
Authors: Johnston Hamish
Published: July 2021

Physicists at the LHCb experiment at CERN have announced the possible existence of a hypothetical particle called a leptoquark.
First ‘space hurricane’ spotted
Authors: Randall Ian
Published: July 2021

An international team of scientists claims to have seen a swirling funnel of plasma in the Earth’s upper atmosphere, though others argue that the observation is not new, as Ian Randall reports
Former senator Bill Nelson nominated to lead NASA
Authors: Gwynne Peter
Published: July 2021

US president Joe Biden has nominated Bill Nelson, a former Democratic senator from Florida and an enthusiastic backer of NASA, as the space agency’s new administrator.
Panel calls for US focus on solar geoengineering
Authors: Gwynne Peter
Published: July 2021

The US should co-ordinate with other countries to initiate a research programme on solar geoengineering that would focus on methods to cool the Earth by reflecting the Sun’s heat back into space. That is according to a report by the US National Academies of Sciences, Engineering, and Medicine
Semiconductor pioneer Isamu Akasaki dies aged 92
Authors: Banks Michael
Published: July 2021

The Japanese semiconductor pioneer Isamu Akasaki has died at the age of 92. His work in the late 1980s and early 1990s led to the development of blue light-emitting diodes (LEDs)
Rooting for women in science
Authors: Borundia Arushi
Published: July 2021

Arushi Borundia says that while stereotypes will always exist, more can be done to change the public’s perception of what a physicist is
Art and science
Authors: Hildreth Scott
Published: July 2021

In response to the 18 March episode of the Physics World Weekly podcast, in which artist Geraldine Cox talks about the links between science and art, and her collaborations with physicists at Imperial College London and other research institutes.
Medical marvels
Authors: Grigorescu Irina
Published: July 2021

Irina Grigorescu, a medical physicist at King’s College London, explains how artificial intelligence can transform medical physics
Powerful partnership
Authors: Esquivel Jessica
Published: July 2021

Experimental particle physicist Jessica Esquivel explores the beneficial collaboration between artificial intelligence and particle physics that is advancing both fields
Intelligent drug discovery
Authors: Wossnig Leonard
Published: July 2021

Leonard Wossnig, chief executive of quantum drug-discovery company Rahko, describes the powerful capabilities of artificial intelligence and quantum computing when combined
Fighting algorithmic bias
Authors: Photopoulos Julianna
Published: July 2021

Physicists are increasingly developing artificial intelligence and machine learning techniques to advance our understanding of the physical world but there is a rising concern about the bias in such systems and their wider impact on society at large. Julianna Photopoulos explores the issues of racial and gender bias in AI – and what physicists can do to recognize and tackle the problem
Judge, jury and AI-xecutioner
Authors: Rao Achintya
Published: July 2021

Achintya Rao reviews A Citizen’s Guide to AI by John Zerilli and co-authors