bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic mirror metasurfaces based on spoof surface plasmonic structures
Authors: Yin Yun-Qiao , Wu Hong-Wei ,   School of Mechanics and Photoelectric Physics, Anhui University of Science and Technology, Huainan 232001, China
Published: December 2020

Mirrors can be seen everywhere in daily life and play an important role in modern optical systems. A traditional mirror, which is made of noble metals, usually has a zero electric field strength and maximal magnetic field strength at its surface induced by the out-of-phase of electric field and in-of-phase of magnetic field between the reflected field and incident field due to the boundary condition of perfect electric conductor. As the magnitude of local electric field determines the strength of the light-matter interaction, it is clear that this interaction is suppressed near the mirror surface. Magnetic mirror, which can enhance electric field on the surface, has been widely applied to strong light-matter interaction for biological sensing, material analysis, and imaging. However, the conventional smooth magnetic mirror with a plane surface is difficult to induce sufficient light-matter interaction when the matter has a complex geometrical shape. Here in this work, we propose a concept of magnetic mirror with a rough interface designed by an array of artificial surface plasmonic structures. The artificial surface plasmonic structure on a subwavelength scale is designed by periodically inserting spiral metallic strips into a dielectric cylinder to support the strong magnetic dipolar resonant mode. The magnetic dipolar resonance of the excited structure is induced by the displacement current circle. Therefore, the resonant frequency is related to the geometrical parameters of the helical structure closely. When we reduce the outer radius of the structure, the magnitude of the displacement current circle will change, resulting in blue-shift of the resonant frequency. At the same time, we also find that increasing the spiral degree of the structure will cause the magnetic dipolar resonance frequency to become red-shifted. Particularly, the same magnetic dipolar mode can be supported in a spiral structure of different size by tuning the spiral degree accordingly. In this context, we design a rough magnetic mirror constructed by the artificial surface plasmonic structures with various sizes, and demonstrate that the efficiency of rough magnetic mirror is in agreement with that of smooth magnetic mirror. The proposed rough magnetic mirror can provide the unique ability to enhance the interaction between light and complicated matter for the application of biological sensing and imaging in microwave and terahertz band.
Reducing dark count of single-photon avalanche diode detector with polysilicon field plate
Authors: Han Dong , Sun Fei-Yang , Lu Ji-Yuan , Song Fu-Ming , Xu Yue ,   College of Electronic and Optical Engineering & College of Microelectronics, Nanjing University of Posts and Telecommunications, Nanjing 210023, China,   Office of Scientific R & D, Nanjing University of Posts and Telecommunications, Nanjing 210023, China,   National and Local Joint Engineering Laboratory of RF Integration & Micro-Assembly Technology, Nanjing 210023, China
Published: December 2020

To suppress the effect of dark count noise on single photon avalanche diode (SPAD) detector, the mechanism and method of reducing the dark count rate (DCR) of SPAD device by using a polysilicon field plate is studied in this paper. Based on the 0.18-μm standard CMOS process, a polysilicon field plate located between the P+ active region and shallow trench isolation (STI) is deposited to reduce the dark count noise for a scaleable P+/P-well/deep N-well SPAD structure. Test results show that the DCR of SPAD device decreases by an order of magnitude after the deposition of polysilicon field plates, and its dark count performance at high temperature is even better than that of device without polysilicon field plate at room temperature. The TCAD simulation further indicates that the peak electric field in the guard ring region of the SPAD device is introduced into the STI by the field plate, and the overall electric field in the guard ring region is reduced by 25%. Finally, through modeling and calculating the DCR, the polysilicon field plate weakens the electric field of the guard ring region with high trap density, hence the trap-related DCR is significantly reduced. Therefore, the dark count performance of SPAD detector is effectively improved.
Chiral Majorana fermion
Authors: Wang Jing ,   State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China
Published: December 2020

The chiral Majorana fermion, is a massless fermionic particle being its own antiparticle, which was predicted to live in (1+1)D (i.e. one-dimensional space plus one-dimensional time) or (9+1)D. In condensed matter physics, one-dimensional (1D) chiral Majorana fermion can be viewed as the 1/2 of the chiral Dirac fermion, which could arise as the quasiparticle edge state of a two-dimensional (2D) topological state of matter. The appearance of an odd number of 1D chiral Majorana fermions on the edge implies that there exist the non-Abelian defects in the bulk. The chiral Majorana fermion edge state can be used to realize the non-Abelian quantum gate operations on electron states. Starting with the topological states in 2D, we illustrate the general and intimate relation between chiral topological superconductor and quantum anomalous Hall insulator, which leads to the theoretical prediction of the chiral Majorana fermion from the quantum anomalous Hall plateau transition in proximity to a conventional s-wave superconductor. We show that the propagation of chiral Majorana fermions leads to the same unitary transformation as that in the braiding of Majorana zero modes, and may be used for the topological quantum computation.
Axially-distributed bubble-bubble interaction under a coustic excitation in pipeline
Authors: Li Xiang , Chen Yong , Feng Hao , Qi Lei ,   School of Precision Instruments and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China,   College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, China,   China Aerodynamics Research and Development Center, Mianyang 621000, China,   Beijing Institute of Spacecraft Environment Engineering, Beijing 100094, China
Published: December 2020

Acoustically-excited bubble dynamics is the foundation of pipeline bubble detection based on acoustic technology. Due to the existence of multiple bubbles in pipeline flow, the Bjerknes forces among arbitrary bubbles under acoustic excitation may enforce bubble-bubble interaction and then change the features of bubble dynamics. Based on traditional free bubble’s Rayleigh-Plesset (R-P) model, this paper tries to establish bubble-bubble interaction model in consideration of the second Bjerknes force and bubble distribution in the pipeline axial direction. Meanwhile, the influence of finite wave speed in compressible fluid is considered. The proposed model is numerically calculated by the fourth-order Runge-Kutta method. Firstly, the differences in bubble feature between the free bubble’s R-P model and bubble-bubble interaction model are compared under excitation with different frequencies and amplitudes. Results show that the differences in bubble dynamics are minor when the bubble’s distance is large enough. When the bubble’s distance is fixed, the differences are significant on condition that the frequency of acoustic excitation is nearly the resonant frequency of bubbles. Secondly, through establishing compressible model and incompressible fluid model, we compare the differences between the two models. Numerical calculations show that the second Bjerknes force under the compressible assumption acts as an external force and forces the bubble to vibrate. On the other hand, the second Bjerknes force under the incompressible assumption changes the dynamics of bubble-bubble interaction as well as the resonant features. Finally, we study the effect of bubble-bubble distance and bubble’s axial position on bubble vibration characteristics. The bubble-bubble distance affects the second Bjerknes force and may lead the bubbles to vibrate nonlinearly. The bubble’s axial position changes the phase of external acoustic force and leads to the difference in initial vibration feature. When this difference is coupled with the second Bjerknes force, the bubble-bubble interaction may be changed even into nonlinear vibration, leading the bubble’s oscillation spectrum to differ from linear vibrations significantly. These results demonstrate that the resonant state of a small bubble may be converted into nonlinear vibration state if the second Bjerknes force is present. On the other hand, the resonant state of a large bubble can keep linear vibration when the second Bjerknes force is not obvious.
Application of heterostructures in halide perovskite photovoltaic devices
Authors: Xi Yu-Ying , Han Yue , Li Guo-Hui , Zhai Ai-Ping , Ji Ting , Hao Yu-Ying , Cui Yan-Xia ,   College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024, China
Published: December 2020

Perovskites are widely used in various kinds of optoelectronic devices, including solar cells, photodetectors, light-emitting diodes, etc., due to their excellent properties such as long carrier diffusion length, high absorption coefficient, low trap state density and so on. Functional materials such as layered two-dimensional materials (graphene, transition metal dichalcogenides, etc.),low-dimensional semiconductor nanostructures (nanoparticles, quantum dots, nanowires, nanotubes,nanorods,nanopieces,etc.), metallic nanostructures(Au,Ag, etc.) and insulating materials (insulating polymer, organic amine, inorganic insulating film, etc.) have attracted more and more attention due to their special chemical, electrical and physical properties.In order to broaden the application of perovskites in photovoltaic devices, perovskites can be combined with various functional materials to form heterostructures so as to combine the advantages of the two types of materials.The heterostructures of perovskites/functional materials can be used as the interface modification layer in halide perovskites photovoltaic devices, to improve the crystallinity of perovskite, effectively reduce the surface defects and suppress the carrier recombination loss at the interface. The heterostructures of perovskites/functional materials can be used as the charge transporting layer in halide perovskites photovoltaic devices, can match well with the perovskite energy levels, which is beneficial to the efficient extraction of holes and electrons. The heterostructures of perovskites/functional materials also can be used as encapsulation layer in halide perovskites photovoltaic devices, to reduce the contact between water and perovskite, it can effectively prevent the degradation of perovskite, to improve the device stability.In addition, the semiconductor with narrow bandgap or array structure can be used to broaden the spectral response and to improve the light absorption of the perovskite photovoltaic devices.In a word, the heterostructures of perovskites/functional materials are applied to devices is an effective way to obtain high performance and low cost photovoltaic devices.In this review, recent works on the applications of the heterostructures in halide perovskite photovoltaic devices are comprehensively presented and discussed. The progress and advantages of the heterostructures as the interface modification layer, charge transporting layers and encapsulation layer in halide perovskite photovoltaic devices are systemically reviewed. Finally, we summarize the whole paper and give a prospect for the development of heterostructures based perovskite photovoltaic devices in the future.
Scatterings and wavefront manipulations of surface plasmon polaritons
Authors: Guan Fu-Xin , Dong Shao-Hua , He Qiong , Xiao Shi-Yi , Sun Shu-Lin , Zhou Lei ,   Department of Physics, Fudan University, Shanghai 200433, China,   Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China,   Department of Communication & Information Engineering, Shanghai University, Shanghai 200444, China
Published: December 2020

Surface plasmon polaritons (SPPs) have found many important applications in on-chip signal transportation, enhanced nonlinear/Raman effect, biological/chemical sensing, super resolution imaging, etc. In these applications, the near-field propagation and far-field scattering of SPPs play a vital role. However, there has been strong desire to understand these physical effects. In this paper, we first briefly review the history and progress of SPPs. Next, we mainly focus on the near-field propagation and far-field scattering of SPPs, including their fundamental theories and practical applications. Finally, we review several different approaches to manipulating the near-field wavefronts of SPPs. These researches offer us a more in-depth understanding and the ability to more strongly control the scattering characteristics of SPPs, which may promote the scientific researches and practical applications of SPPs in the future.
Research progress of protein-based memristor
Authors: Shi Chen-Yang , Min Guang-Zong , Liu Xiang-Yang ,   Research Institute for Biomimetics and Soft Matter,College of Materials, Xiamen University, Xiamen 361005, China,   Faculty of Science, National University of Singapore, Singapore 119077, Singapore
Published: December 2020

Memristor, as a new type of electronic component that can realize high density, multi-function, low power consumption, and multi-level data storage, has brought significant changes to the field of circuit structure design, information storage theory, and artificial synapses simulation. In a wide range of memristors, the protein-based memristors have unparalleled natural advantages in other cutting-edge information technology fields such as implantable computing, human-computer interaction, and human-computer integration due to their controllable degradation, rich and cheap raw materials, and biocompatibility. Therefore, the memristor is considered as the most potential candidate for building the next generation of high-tech information electronic device. In this article, the latest research progress of protein based memristors is comprehensively reviewed. The research progress of other proteins, including the widely studied egg albumen and artificial recombinant protein with excellent performance are first summarized, and then the research process of silk fibroin-based memristors, the performance improvement of silk fibroin-based memristors brought by functional strategies are comprehensively introduced. The Structure-activity relationship between structure and performance of functionalized silk fibroin is analyzed. Finally, the performance of the protein-based memristor is comprehensively analyzed, and the future development opportunities of the green electronic device are also prospected.
Influence of Hall effect on hypersonic magnetohydrodynamic control
Authors: Ding Ming-Song , Fu Yang-Ao-Xiao , Gao Tie-Suo , Dong Wei-Zhong , Jiang Tao , Liu Qing-Zong ,   Computational Aerodynamics Institute, China Aerodynamics Research and Development Center, Mianyang 621000, China
Published: December 2020

In this paper, the influence of Hall effect on hypersonic magnetohydrodynamic control is studied. By considering high temperature thermo-chemical reactions, the excitation of thermodynamic temperature of gas molecules, Hall coefficient distribution of various ionized components, and by solving the coupled anisotropic Possion’s equation of Hall electric field and the high temperature thermo-chemical non-equilibrium flow governing equations with electromagnetic source term, the numerical simulation method of the Hall effect on hypersonic magnetohydrodynamic (MHD) control is established, and the numerical simulation of hypersonic MHD control under various conditions is conducted, the mechanism of “leakage” and “gathering” phenomenon of Hall effect and its influence on aerodynamic force and aerothermal environment are analyzed, the mechanism and its influences of Hall effect under various flight altitudes, flight speeds and characteristic lengths are discussed in detail. The result shows that 1) Hall effect changes the Lorentz force distribution of plasma, weakens the total mechanical effect, thus lowering the total magneto-resistance effect. 2) The influence of Hall effect on hypersonic MHD control is closely related to the wall conductivity and the “leakage” phenomenon of the leakage layer near the wall. The “leakage” phenomenon must be restrained in order to enhance the magnetic control effect. 3) The influence of Hall effect on magnetic control thermal protection is complicated, which is the combined result of the “leakage” and “gathering” phenomenon. 4) Based on the normal state in this paper, when the flight altitude is higher than 67 km or the flight speed higher than 5.7 km/s or the characteristic length is bigger than 0.5 m, Hall effect can enhance the magnetic control thermal protection, and the current “gathering” phenomenon dominates the influence on aerothermal environment. On the contrary, Hall effect can weaken the effect of magnetic control thermal protection, and the “leakage” phenomenon dominates the influence on aerothermal environment.
All-optical devices based on two-dimensional materials
Authors: Xu Yi-Quan , Wang Cong ,   College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
Published: December 2020

The leap in communication technology in recent years has brought new challenges to the compactness, modulation speed, working bandwidth and control efficiency of modulation equipment. The discovery of graphene has led the two-dimensional materials to develop rapidly, and a series of new materials have continuously emerged, such as MXene, black phosphorus, transition metal sulfides, etc. These new two-dimensional materials have excellent nonlinear optical effects, strong light-matter interaction, and ultra-wide working bandwidth. Using their thermo-optic effect, nonlinear effect and the combination with optical structure, the needs of ultra-fast modulation in optical communication can be met. Compact, ultra-fast, and ultra-wide will become the tags for all-optical modulation of two-dimensional materials in the future. This article focuses on all-optical devices based on thermo-optical effects and non-linear effects of two-dimensional materials, and introduces fiber-type Mach-Zehnder interferometer structures, Michelson interferometer structures, polarization interferometer structures, and micro-ring structures. In this paper, the development status of all-optical devices is discussed from the perspectives of response time, loss, driving energy, extinction ratio, and modulation depth. Finally, we review the latest developments, analyze the challenges and opportunities faced by all-optical devices, and propose that all-optical devices should be developed in the direction of ring resonators and finding better new two-dimensional materials. We believe that all-optical devices will maintain high-speed development, acting as a cornerstone to promote the progress of all-optical systems.
Stretchable self-powered epidermal electronics from piezoelectric rubber for tactile sensing
Authors: Yao Kuan-Ming , Yao Jing-Yi , Hai Zhao , Li Deng-Feng , Xie Zhao-Qian , Yu Xin-Ge ,   Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China,   State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian 116023, China
Published: December 2020

Soft, thin, skin-integrated electronics, i.e. epidermal electronics, has become a hotspot in biomedical engineering and drawn great attention for their applications in health monitoring, disease diagnosis and therapies. However, soft powering system is still a challenge for epidermal electronics, since the thickness and weight of the existing flexible energy harvesting and storage devices are very hard to meet the requirements of epidermal electronics. Here we present a stretchable and flexible self-powering epidermal electronic device based on rubbery piezoelectric composites formed by a ternary blend of PDMS, lead zirconate titanate (PZT) and graphene. The mixed PZT rubber is soft, ultra-thin and light weight and intrinsically stretchable. By combining soft PDMS substrate and advanced mechanics designed interdigital electrodes/interconnects, a stretchable and skin-integrated device for tactile sensing is realized. The soft device can not only accurately measure a board range of force from 2.84 kPa to 11.72 kPa but also exhibit great flexibility that can maintain stable performance under various mechanical deformations, such as bending, stretching and twisting. On-skin demonstration tests reveal that this self-powering device can clearly distinguish the differences among mechanical stimulations such as touching, poking, tapping and hitting. Furthermore, the self-powering nature of these devices allows energy to be harvested from daily body actives, for instance, hard touching by hand can lighten up to 15 light-emitting diodes.
Energetic potential of hexogen constructed by machine learning
Authors: Wang Peng-Ju , Fan Jun-Yu , Su Yan , Zhao Ji-Jun ,   Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, Ministry of Education, Dalian University of Technology, Dalian 116024, China
Published: December 2020

1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) or hexogen, a high-insensitivity explosive, the accurately description of its energy and properties is of fundamental significance in the sense of security and application. Based on the machine learning method, high-dimensional neural network is used to construct potential function of RDX crystal. In order to acquire enough data in neural network learning, based on the four known crystal phases of RDX, the structural global search is performed under different spatial groups to obtain 15199 structure databases. Here in this study, we use nearby atomic environment to build 72 different basis functions as input neurons, in which the 72 different basis functions represent the interaction with nearby atoms for each type of element. Among them, 90% data are randomly set as training set, and the remaining 10% data are taken as test set. To obtain the better training effect, 9 different neural network structures carry out 2000 step iterations at most, thereby the 30-30-10 hidden layer structure has the lower root mean square error (RMSE) after the 1847 iterations compared with the energies from first-principles calculations. Thus, the potential function fitted by 30-30-10 hidden layer network is chosen in subsequent calculations. This constructed potential function can reproduce the first-principles results of test set well, with the RMSE of 59.2 meV/atom for binding energy and 7.17 eV/Å for atomic force. Especially, the RMSE of the four known RDX crystal phases from 1 atm to 6 GPa are 10.0 meV/atom and 1.11 eV/Å for binding energy and atomic force, respectively, indicating that the potential function has a better description of the known structures. Furthermore, we also propose four additional RDX crystal phases with lower enthalpy, which may be alternative crystal phases undetermined in experiment. In addition, based on molecular dynamics simulation with this potential function, the α-phase RDX crystal can stay stable for a few ps, further proving the applicability of our constructed potential function.
Sensing mechanisms and applications of flexible pressure sensors
Authors: Hou Xing-Yu , Guo Chuan-Fei ,   Department of Material Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
Published: December 2020

As an emerging type of electronic devices, flexible pressure sensors have more advantages than rigid sensors in human-computer interaction, healthcare, and tactile sensing in robots. These advantages, however, require the materials to be thin and soft. For applications in human bodies, the sensor needs to be biocompatible and mechanically match the biotissue such that they can be conformable to the skin textures, or be implanted in the body. Sensitivity, response time, limitation of detection, and stability are basic properties to evaluate a pressure sensor. Recently, some other parameters of flexible pressure sensors including pressure response range, pressure resolution, space resolution, and stretchability have also been studied, enabling such devices to have a wider application prospect. This review introduces about the state of the arts of flexible pressure sensors in recent years, and is intended to discuss the sensing mechanisms, properties, and potential applications of flexible tactile sensors. At last, we talk about the future of flexible tactile sensors.
Combinatorial film and high-throughput characterization methods of phase diagram for high-Tc superconductors
Authors: Jin Kui , Wu Jie ,   Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China,   School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China,   Songshan Lake Materials Laboratory, Dongguan 523808, China,   Key Laboratory for Quantum Materials of Zhejiang Province, School of Science, Westlake University, Hangzhou 310024, China,   Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
Published: December 2020

 Cuprate and iron-based superconductors are known as the only two types of high-Tc superconductors. The mechanism of high-Tc superconductivity is the most challenging issue in the field. Building accurate high-dimensional phase diagram and exploring key parameters that determine Tc, would be essential to the comprehension of high-Tc mechanism. The electronic phase diagrams of cuprate superconductors show complexity and diversity, for the strong coupling and interplay among lattice, orbital, charge and spin degrees of freedom. It is tough to construct a high-dimensional holographic phase diagram and obtain quantitative laws by traditional research methods. Fortunately, the high-throughput synthesis and fast screening techniques enable to probe the phase diagram via line-by-line or map scanning modes, and thereby are expected to obtain high-dimensional phase diagram and key superconducting parameters in a much efficient way.

 In this article, electronic phase diagrams of cuprate superconductors that are obtained mainly by electrical transport measurements, are briefly summarized in the view of cation substitutions, oxygen variation in the parent compounds, electric double-layer gating (electrostatic/electrochemical manipulation) and magnetic field. We introduce the preparation methods for combinatorial film based on the developed pulsed laser deposition and oxide molecular beam epitaxy techniques, as well as corresponding scale-span high-throughput measurement techniques. These high-throughput techniques have been successfully applied in the research of interface superconductivity, quantum phase transition, and so on. The novel high-throughput superconductivity research mode will play an indispensable role in the construction of the high-dimensional holographic phase diagram, the comprehension of high-Tc mechanism, and practical applications of superconductors.
Muscle signals to the rescue
Authors: Diaz Arely V , Reis Tânia
Published: December 2020

The skeletal muscle of fruit flies communicates with other organs to prevent the accumulation of too much fat and to protect adults against obesity.
Sumterms, Summands, Sumtuples, and Sums and the Meta-Arithmetic of Summation
Authors:   Informatics Institute, Faculty of Science, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, the Netherlands, Bergstra Jan
Published: December 2020

Sumterms are introduced as syntactic entities, and sumtuples are introduced as semantic entities. Equipped with these concepts a new description is obtained of the notion of a sum as (the name for) a role which can be played by a number. Sumterm splitting operators are introduced and it is argued that without further precautions the presence of these operators gives rise to an instance of the so-called sum splitting paradox. A survey of solutions to the sum splitting paradox is given.
Synoptic revision of the fern genus Elaphoglossum Schott ex J.Sm. (Dryopteridaceae) in Madagascar, with the description of 23 new taxa, all but one endemic
Authors: Rouhan Germinal
Published: December 2020

After 15 years of field studies in Madagascar, especially focused on the overlooked fern genus Elaphoglossum (Dryopteridaceae), a synoptic revision of the genus is here presented. Based on more than 2,600 herbarium specimens including collections over 200 years, Elaphoglossum is the second most diversified fern genus in Madagascar, with 52 species and three subspecies (with 76% of endemism). It is to be compared to the 34 species treated by Tardieu-Blot in 1960 for the “Flore de Madagascar et des Comores” or the 38 species listed by Roux in 2009 in the seminal “Synopsis of the Lycopodiophyta and Pteridophyta of Africa, Madagascar and neighboring islands”. The 55 taxa represent five out of seven existing generic sections (sect. Amygdalifolia and sect. Wrightiana being monotypic and Neotropical): sect. Lepidoglossa (29 spp. and three subspp.), sect. Elaphoglossum (17 spp.), sect. Setosa (3 spp.), sect. Squamipedia (2 spp.), and sect. Polytrichia (1 sp.). Distribution is given for each species and subspecies, and detailed for each island or archipelago in the Western Indian Ocean (La Réunion, Mauritius, Seychelles, and Comoros). Twenty species and three subspecies are newly described, all but one endemic to Madagascar: Elaphoglossum ambrense Rouhan, Elaphoglossum andohahelense Rouhan, Elaphoglossum anjanaharibense Rouhan, Elaphoglossum approximatum Rouhan, Elaphoglossum brachymischum Rouhan, Elaphoglossum cerussatum Tardieu subsp. brunneum Rouhan, Elaphoglossum coracinolepis Rouhan, Elaphoglossum desireanum Rouhan, Elaphoglossum glabricaule Rouhan, Elaphoglossum gladiifolium Rouhan, Elaphoglossum leucolepis (Baker) Krajina ex Tardieu subsp. nanolepis Rouhan, Elaphoglossum leucolepis (Baker) Krajina ex Tardieu subsp. nigricans Rouhan, Elaphoglossum longiacuminatum Rouhan, Elaphoglossum patriceanum Rouhan, Elaphoglossum perangustum Rouhan, Elaphoglossum prominentinervulum Rouhan, Elaphoglossum rakotondrainibeae Rouhan, Elaphoglossum repandum Rouhan, Elaphoglossum sabineanum Rouhan, Elaphoglossum sinensiumbrarum Rouhan, Elaphoglossum subglabricaule Rouhan, Elaphoglossum tsaratananense Rouhan, and Elaphoglossum viridicaule Rouhan. Morphological description, distribution map, and original illustrations are provided for each new taxon. Novel identification keys to the sections and all species from Madagascar are also presented.
Improved plaque assay for human coronaviruses 229E and OC43
Authors: Bracci Nicole , Pan Han-Chi , Lehman Caitlin , Kehn-Hall Kylene , Lin Shih-Chao
Published: December 2020

In light of the COVID-19 pandemic, studies that work to understand SARS-CoV-2 are urgently needed. In turn, the less severe human coronaviruses such as HCoV-229E and OC43 are drawing newfound attention. These less severe coronaviruses can be used as a model to facilitate our understanding of the host immune response to coronavirus infection. SARS-CoV-2 must be handled under biosafety level 3 (BSL-3) conditions. Therefore, HCoV-229E and OC43, which can be handled at BSL-2 provide an alternative to SARS-CoV-2 for preclinical screening and designing of antivirals. However, to date, there is no published effective and efficient method to titrate HCoVs other than expensive indirect immunostaining. Here we present an improved approach using an agarose-based conventional plaque assay to titrate HCoV 229E and OC43 with mink lung epithelial cells, Mv1Lu. Our results indicate that titration of HCoV 229E and OC43 with Mv1Lu is consistent and reproducible. The titers produced are also comparable to those produced using human rhabdomyosarcoma (RD) cells. More importantly, Mv1Lu cells display a higher tolerance for cell-cell contact stress, decreased temperature sensitivity, and a faster growth rate. We believe that our improved low-cost plaque assay can serve as an easy tool for researchers conducting HCoV research.
Role of Radiologist in Diagnosis of Neonatal Small Left Colon Syndrome: A Case Report
Authors: Gele Ibrahim Haruna , Sule Muhammad Baba , Maaji Sadisu Mohammed , Musa Abubakar , Abacha Muhammad
Published: December 2020

Neonatal small left colon syndrome is a well-defined functional disease of the lower colon and it results in signs and symptoms of intestinal obstruction. It is an uncommon cause of neonatal intestinal obstruction characterised by an abrupt transition of intestinal caliber at or near the splenic flexure. More than 50% of affected patients are born to mothers with diabetes. We report a five-day-old neonate who presented with abdominal distension and vomiting diagnosed to have small left colon syndrome by contrast enema. He had surgical resection of the narrowed segment and anastomosis with subsequent resolution of symptoms.
Incidence of Diphtheria among Clinically Probable Cases in a Tertiary Care Centre- A Prospective Study
Authors: Sowjanya Gunturu , Sarguna Pennagaram
Published: December 2020

Introduction: Diphtheria is a vaccine preventable communicable acute infectious disease of upper respiratory tract caused by Corynebacterium diphtheriae (C. diphtheria) which is endemic in India. Delayed diagnosis of the disease leads to spread of infection in the community and causes increased morbidity and mortality in the affected individuals. To reduce the delay, an early attempt for microbiological diagnosis of diphtheria should be done as it is crucial and complimentary to clinical diagnosis. Aim: To know the prevalent toxin producing biotypes of Corynebacterium among the clinically probable cases of diphtheria. Materials and Methods: Throat swab samples from 300 clinical cases of diphtheria were processed by direct microscopy and culture. Microscopic examination was done by direct throat swab and samples were inoculated in Loeffler’s Serum Slope (LSS). Antimicrobial susceptibility testing was done by Kirby-Bauer disc diffusion method. Results were analysed using MS Excel. Results: Out of 300 samples, presumptive diagnosis of diphtheria by microscopic examination of direct throat swab was 3% and swab inoculated in LSS was 10%. Confirmed cases of diphtheria by culture were 48 (16%). A 100% sensitivity was seen for all antibiotics tested for all 48 isolates in antimicrobial susceptibility testing. Conclusion: A shift in the age wise incidence of the disease from pre-school to school age has been observed with more cases reported. C. diphtheriae gravis was the highly prevalent strain isolated. Culture should be considered as confirmatory method for diagnosis.
Critical Drinking Habit and Its Implications for Alcoholics in the Family Premises: A Case Study of Punjab (India)
Authors: Kumar Honey
Published: December 2020

Drinking has become a major area of concern in contemporary modern world. It has both positive and negative consequences depending upon the pattern of use of this substance. The present article talks about the negative consequences of critical drinking. In particular, it discusses how critical drinking manifests into different types of problems for the alcoholics, and causes the problem of alcoholism in society. The main objective of this study is to understand how alcoholism ruins the life of alcoholics and the kind of problems they face due to their critical addiction in the family premises. The research question for the present study is to  determine whether alcoholics are the problem creator in society, or they are also victims of their habits? This study is based on primary data collected from 100 alcoholics from different parts of Punjab while keeping in mind the definition of alcoholic. And, in order to   generate the primary data of the present study, the methods like snowballing technique, semi-structured interview schedule, participant observation etc. have been used. The study has found that the alcoholics face multiple social problems, which vary from minor to major,  due to their critical drinking habit. In most of the cases, normal drinking habit turns into critical drinking pattern, which increases the possibility of troubles for alcoholics as well as for others. The study concludes that alcoholics are not merely the troublemakers in society but they are also the victims of their own misfortune. Moreover, these problems further worsen the alcoholics’ drinking habits. Resultantly, this all turns into the vicious circle of excessive drinking and associated problems.
Analysis of Scale-Efficiency of Rice Production among Beneficiaries of Anchor Borrowers Programme in Adamawa State, Nigeria
Authors: Bitrus A. , Sulumbe I. M. , Ibrahim A. , Yakubu H.
Published: December 2020

This study examined the scale efficiency of rice production among beneficiaries of anchor borrowers programme (ABP) in Adamawa State, Nigeria. Multistage random sampling was employed to select respondents for the study. Structured questionnaires were the instruments used for data collection. A sample of 139 farmers was used for the study. Percentages, means, frequency, ranking, and data envelopment analysis were the analytical tools employed. The results of the socioeconomic characteristics of the respondents revealed that the majority (76.3%) of them was headed by males; most (61.1%) were within the ages of 21-40 years. Results from the data envelopment analysis showed that mean scale efficiency observed was 59%, out of the rice farms studied; 78% were scale inefficient as they operated under increased return to scale (IRS) and decreased return to scale (DRS) assumptions and therefore, operated at stage I and stage III of the production process, respectively. The major constraints faced by rice farmers in the study area were identified among others to be prevalence of pests and diseases, bad roads, and high cost of labour. Finally, it was recommended among others that policies geared towards investment in pest and disease control, good access roads to farms and means of transport towards achieving effective productivity and scale efficiency should be formulated.
Raffia Forest Exploitation and Socio-Economic Development within Nkongsamba Urban Council
Authors: Samba Gideon , Kuma Japhet Chianebeng
Published: December 2020

In Nkongsamba of the Littoral region, raffia palms exploitation have offered an impressive assortment of products for food,  housing construction and households equipment to many of the community members who greatly depend on this Non-Timber Forest Products (NTFPs) for livelihood. This study examines the relationship between raffia forest exploitation and socio-economic development within the Nkongsamba urban council in the Littoral Region of Cameroon. To achieve the main aim of the study, specific objectives were set to examine the socio-economic activities related to raffia forest exploitation in Nkongsamba, assess the relationship between raffia forest activity and socio-economic development of Nkongsamba. Data for the study were obtained through primary and secondary sources using a mixed design method of inquiry which combines both quantitative and qualitative approaches to explore data on raffia forest and its related activities in the study area. Purposive and systematic sampling techniques were equally employed for a sample population of 155 that was drawn using Miller & Brewer Sample determination Method (2003). The data generated were analysed with descriptive and inferential statistics using Statistical Package for Social Sciences (SPSS) version 20. The major results from the analysis of the findings indicate that raffia activities have contributed enormously to socio-economic development. The researcher used linear regression statistics to determine if raffia forest activities have any significant impact on socio-economic development at .05 significant levels. The results showed that the calculated p-value .014 was not up to the significant level .05 placed for the study. This therefore accepts the fact that raffia forest activities have significant effect on socio-economic development. Base on this finding, the study recommended that, in view of the fact that raffia exploitation is the main economic base activity to majority of households in the area under study, the government should enact appropriate polices to promote the potentials of raffia farming households. Such households should be provided with inputs such as improved raffia harvesting materials at affordable rates.
Implications of Philately in Promoting the Protected Natural Areas (V) - Rodna Mountains National Park
Authors: Cioruța Bogdan-Vasile , Coman Mirela , Helindian Andrei Nicolae , Pop Alexandru Leonard
Published: December 2020

As part of the natural heritage, our country (Romania) is a blessed place with many areas of unique beauty, with places where the spectacle of nature delights your eyes and take your breath with every step. Constantly promoting philatelic themes that use natural wealth and the beauty of our country as subjects, the administrative entity (with various names over time), nowadays Romfilatelia, responsible for issuing postage stamps performs a series of postage stamps in whose images are found rarities of flora and fauna, a miracle of nature. To show that protected natural areas have a special beauty, and to make them known to everyone and also to show the implications of thematic philately in the promotion of protected areas in the country and abroad, in this paper, we bring to the discussion the most significant philatelic peculiarities (stamps, first-day covers, illustrated and semi-illustrated postcard, maximum postcards, etc) related to the Rodna Mountains National Park.
Influence of TiO2 Nanocrystals on Alkyd Resin Paint Films to Protect Metals
Authors: Hai Le Huy , Truc Le Mai Xuan , Trung Nguyen Quoc
Published: December 2020

Aim and Objectives: Nowadays, nanomaterials technology is developing very quickly and bringing high economic efficiency for many industries including paint. The purpose of this study is to assess the effect of paint properties when replacing TiO2 powder coating with nano TiO2 at different ratios.

Materials and Methods: The research method is selecting the traditional alkyd paint formula, then replacing this coating powder TiO2 with nano TiO2 to monitor the properties of the paint film over time. Methods of analyzing the properties of the paint film are based on Vietnam standards.

Results: The study results showed that TiO2 coating powder replaced by TiO2 nanomaterials has increased the properties of the paint film, improving the thickness, gloss, and durability of the paint film. Nano TiO2 increases from 0.5% to 24% by weight, the impact increased by about 11% (73 to 82 kg.cm), Glossy 60° increased by about 12%, Glossy 85° increased by about 12%, especially the durability of paint film over time increased nearly double. Nano TiO2 is a more expensive material than TiO2, so it should replace less than 4% by weight to increase the quality of the paint film, this ratio is changed according to the actual equipment requirements.

Conclusions: The higher the rate of replacing TiO2 materials with TiO2 nano, the better the properties of the paint film. Therefore, nano-material TiO2 is a good coating in alkyd resin for metal paint, it improves the properties of paint film better than TiO2 material.
Exploring Job Crafting: Identifying the Way Lecturers of CLCS Adjust to Their Job
Authors: Dorji Jigme , Drakpa Dawa
Published: December 2020

This study aimed to examine the job crafting practice among the lecturers of College of Language and Culture Studies (CLCS), Bhutan. The study applied quantitative research approach and used Slemp and Vella-Brodrick’s [1] Job Crafting Questionnaire to collect data. The data were collected from 42 lecturers (Male=35 and Female=7) of the college, and analyzed using SPSS to calculate descriptive analysis, frequency, mean and standard deviation. The findings showed that the participants of this study were highly engaged in job crafting. Of three forms of job crafting, relational crafting, cognitive crafting and task crafting, the findings suggested that participants were most likely to be engaged in relational crafting. Further, the findings showed that the lecturers who lacked job resources engaged more in job crafting. Also, it was found that while the gender does not influence job crafting practice, the demographic factor such as participants’ qualification and number of years in the job seem to be affecting their job crafting practice. The study has drawn some strategic implication for employee engagement and wellbeing enhancement.
Growth and Stability of Basmati and Non-basmati Rice Export in India
Authors: Udhayakumar M. , Karunakaran K. R.
Published: December 2020

International trade plays an important role in the economic development of a country. India stands as a world's largest producer and exporter of basmati rice. During 2017-18 the country has exported globally about 40.56 Lakh tonnes of Basmati Rice and 86.48 Lakh tonnes for Non-Basmati rice, the worth of  268.70billion and  229.68 billion respectively. India is the leading exporter of the rice as there is a strong demand for Indian rice in the international markets. So, the present study isto assess the trend and instability in terms export of basmati and non-basmati rice in India. The study has revealed that Indian rice exports performance during the study period 1980-81 to 2017-18. Further, the study period will be divided into three sub-periods. In overall period, the basmati rice export value is highest (16.45 per cent per annum) when compared to the export quantity (8.35 per cent per annum) and unit value (7.48 per cent per annum). In overall period, compound growth rate shows positive growth rate for quantity, value, and unit value of non-basmati rice with 1 per cent level of significance. The compound growth rate total rice shows positive growth rate for quantity (11.06 per cent), value (17.87 per cent), and unit value (6.13 per cent) of total rice with 1 per cent level of significance. Based on the result of the analysis, the instability index was found to be higher for export quantity (51.86%) of basmati rice than its value (88.07%) and unit value (31.23%). Overall, the rice export analysis indicates positive signals for the export of basmati and non-basmati rice from India. Which is confirmed through increasing growth in III period after 2010 and also having stability in the rice export price both basmati and non-basmati rice in the international markets.
Effect of Chemical Manipulation on Growth, Yield and Fiber Traits of Compact Cotton
Authors: Rakavi B. , Chandrasekhar C. N. , Kumar M. , Arul L. , Boopathi N. Manikanda , Jeyakumar P. , Vijayalakshmi D.
Published: December 2020

Crop management is one of the most important factors in modern agricultural activity. Studying the balance of growth stages and supplying optimal quantities of mineral nutrients and hormones to growing plants is essential to improve yield in short duration cotton varieties. In recent years, several approaches have been tried to break this yield plateau. The present investigation was intended to study and improve the yield of newly released variety Co 17 (compact cotton) by foliar application of nutrients, growth hormones, growth retardants and nutrient consortium. The treatments are mepiquat chloride (0.015%), potassium silicate (0.5%), Potassium schoenite (0.5%), borax (0.3%), salicylic acid (0.01%), calcium silicate (0.5%) and TNAU cotton plus (1.25%). Foliar application of different treatments at peak vegetative and flowering stage significantly influenced the leaf traits, root traits, and yield. Nutrient consortium (TNAU cotton plus – 53% over control) and growth retardant (mepiquat chloride- 42% over control) increased the seed cotton yield.