bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of proportion of the HDL-cholesterol subclasses HDL-2b and HDL-3 and macrovascular events among patients undergoing hemodialysis
Authors: Lee Wen-Chin , Chen Jin-Bor , Moi Sin-Hua , Yang Cheng-Hong
Published: January 2021

Altered high-density lipoprotein cholesterol (HDL-C) subclass distribution in hemodialysis (HD) patients is well documented. Aim of this study is to investigate the relationship between HDL-C subclass distribution and macrovascular events in patients undergoing HD. A total of 164 prevalent HD patients and 71 healthy individuals in one hospital-facilitated clinic were enrolled from May 2019 to July 2019 and individual HD patients was follow-up for one year. Macrovascular events (cerebral stroke, coronary heart disease) were recorded in the study period. The HDL-2b, HDL-3 proportions and biochemical parameters were measured. Pearson correlation test and logistic regression analysis were used to examine correlation and odds ratio (OR). 144 HD patients completed one-year follow-up. Cohort with macrovascular events revealed significantly lower HDL-2b and higher HDL-3 subclass proportions compared to those without events. By multivariable adjustment, HDL-3 subclass proportion revealed significantly increase risk for these events (OR 1.17, 95% CI 1.02–1.41, P = 0.044). HDL-2b subclass was significantly higher and HDL-3 subclass was significantly lower in the HD cohort under the hs-CRP level of < 3 mg/L compared to higher hs-CRP level. In conclusion, HDL-2b and HDL-3 subclasses distributions were associated with macrovascular events in HD patients. Proinflammatory status influences the distribution of HDL-2b and HDL-3 subclasses in HD patients.
Preferential lattice expansion of polypropylene in a trilayer polypropylene/polyethylene/polypropylene microporous separator in Li-ion batteries
Authors: Hsu Wen-Dung , Yang Po-Wei , Chen Hung-Yuan , Wu Po-Hsien , Wu Pin-Chin , Hu Chih-Wei , Saravanan Lakshmanan , Liao Yen-Fa , Su Yen-Teng , Bhalothia Dinesh , Chen Tsan-Yao , Chang Chia-Chin
Published: January 2021

The abnormal lattice expansion of commercial polypropylene (PP)/polyethylene (PE)/polypropylene (PP) separator in lithium-ion battery under different charging current densities was observed by in-situ X-ray diffraction. Significant lattice changes of both PP and PE were found during the low current density charging. The capacity fading and the resistance value of the cell measured at 0.025 C (5th retention, 92%) is unexpectedly larger than that at 1.0 C (5th retention, 97.3%) from the electrochemical impedance spectroscopic data. High-resolution scanning electron microscopy is employed to witness the pore changes of the trilayered membrane. Density functional theory calculations were used to investigate the mechanism responsible for the irregular results. The calculations revealed that the insertion of Li-ion and EC molecule into PP or PE are thermodynamically favourable process which might explain the anomalous significant lattice expansion during the low current density charging. Therefore, designing a new separator material with a more compact crystalline structure or surface modification to reduce the Li insertion during the battery operation is desirable.
Metagenomic analysis of the cow, sheep, reindeer and red deer rumen
Authors: Glendinning Laura , Genç Buğra , Wallace R. John , Watson Mick
Published: January 2021

The rumen microbiota comprises a community of microorganisms which specialise in the degradation of complex carbohydrates from plant-based feed. These microbes play a highly important role in ruminant nutrition and could also act as sources of industrially useful enzymes. In this study, we performed a metagenomic analysis of samples taken from the ruminal contents of cow (Bos Taurus), sheep (Ovis aries), reindeer (Rangifer tarandus) and red deer (Cervus elaphus). We constructed 391 metagenome-assembled genomes originating from 16 microbial phyla. We compared our genomes to other publically available microbial genomes and found that they contained 279 novel species. We also found significant differences between the microbiota of different ruminant species in terms of the abundance of microbial taxonomies, carbohydrate-active enzyme genes and KEGG orthologs. We present a dataset of rumen-derived genomes which in combination with other publicly-available rumen genomes can be used as a reference dataset in future metagenomic studies.
Sedimentary microplastic concentrations from the Romanian Danube River to the Black Sea
Authors: Pojar Iulian , Stănică Adrian , Stock Friederike , Kochleus Christian , Schultz Michael , Bradley Chris
Published: January 2021

A multitude of recent studies have detailed microplastic concentrations in aquatic and terrestrial environments, although questions remain over their ultimate fate. At present, few studies have detailed microplastic characteristics and abundance along a freshwater–marine interface, and considerable uncertainties remain over the modelled contribution of terrestrial and riverine microplastic to the world’s oceans. In this article, for the first time, we detail sedimentary microplastic concentrations along a River–Sea transect from the lower reaches of a major continental river, the River Danube, through the Danube Delta, the Black Sea coast to the Romanian and Bulgarian inner shelf of the Black Sea. Our results indicate that isolated areas of the Danube Delta are still relatively pristine, with few microplastic particles in some of the sediments sampled.
Effects of biotin on promoting anammox bacterial activity
Authors: Li Qinyu , Chen Jinhui , Liu Guo-hua , Xu Xianglong , Zhang Qian , Wang Yijin , Yuan Junli , Li Yinghao , Qi Lu , Wang Hongchen
Published: January 2021

Anaerobic ammonium oxidation (anammox) bacteria significantly improve the efficiency and reduce cost of nitrogen removal in wastewater treatment plants. However, their slow growth and vulnerable activity limit the application of anammox technology. In this paper, the enhancement of biotin on the nitrogen removal activity of anammox bacteria in short-term batch experiments was studied. We found that biotin played a significant role in promoting anammox activity within a biotin concentration range of 0.1–1.5 mg/L. At a biotin concentration of 1.0 mg/L, the total nitrogen removal rate (NRR) increased by 112%, extracellular polymeric substance (EPS) secretion and heme production significantly improved, and anammox bacterial biomass increased to maximum levels. Moreover, the predominant genus of anammox bacteria was Candidatus Brocadia.
N-doped graphene foam obtained by microwave-assisted exfoliation of graphite
Authors: Skorupska Malgorzata , Ilnicka Anna , Lukaszewicz Jerzy P.
Published: January 2021

The synthesis of metal-free but electrochemically active electrode materials, which could be an important contributor to environmental protection, is the key motivation for this research approach. The progress of graphene material science in recent decades has contributed to the further development of nanotechnology and material engineering. Due to the unique properties of graphene materials, they have found many practical applications: among others, as catalysts in metal-air batteries, supercapacitors, or fuel cells. In order to create an economical and efficient material for energy production and storage applications, researchers focused on the introduction of additional heteroatoms to the graphene structure. As solutions for functionalizing pristine graphene structures are very difficult to implement, this article presents a facile method of preparing nitrogen-doped graphene foam in a microwave reactor. The influence of solvent type and microwave reactor holding time was investigated. To characterize the elemental content and structural properties of the obtained N-doped graphene materials, methods such as elemental analysis, high-resolution transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy were used. Electrochemical activity in ORR of the obtained materials was tested using cyclic voltamperometry (CV) and linear sweep voltamperometry (LSV). The tests proved the materials’ high activity towards ORR, with the number of electrons reaching 3.46 for tested non-Pt materials, while the analogous value for the C-Pt (20 wt% loading) reference was 4.
A cross-species assessment of behavioral flexibility in compulsive disorders
Authors: Benzina Nabil , N’Diaye Karim , Pelissolo Antoine , Mallet Luc , Burguière Eric
Published: January 2021

Lack of behavioral flexibility has been proposed as one underlying cause of compulsions, defined as repetitive behaviors performed through rigid rituals. However, experimental evidence has proven inconsistent across human and animal models of compulsive-like behavior. In the present study, applying a similarly-designed reversal learning task in two different species, which share a common symptom of compulsivity (human OCD patients and Sapap3 KO mice), we found no consistent link between compulsive behaviors and lack of behavioral flexibility. However, we showed that a distinct subgroup of compulsive individuals of both species exhibit a behavioral flexibility deficit in reversal learning. This deficit was not due to perseverative, rigid behaviors as commonly hypothesized, but rather due to an increase in response lability. These cross-species results highlight the necessity to consider the heterogeneity of cognitive deficits in compulsive disorders and call for reconsidering the role of behavioral flexibility in the aetiology of compulsive behaviors.
Magnetic resonance thermometry using a GdIII-based contrast agent
Authors: Subasinghe S. A. Amali S. , Romero Jonathan , Ward Cassandra L. , Bailey Matthew D. , Zehner Donna R. , Mehta Prakrut J. , Carniato Fabio , Botta Mauro , Yustein Jason T. , Pautler Robia G. , Allen Matthew J.
Published: January 2021

The complexes described here serve as contrast agents for magnetic resonance imaging thermometry.
Photo-oligomerization by shifting the coordination site in a luminescent coordination polymer
Authors: Song Wei-Chao , Geng Chen-Chen , Li Sheng-Yang , Liang Ling , Wang Xiu-Guang , Yang En-Cui , Zhao Xiao-Jun
Published: January 2021

The photo-oligomerization of a diolefinic ligand by shifting the coordination site in a ZnII-based CP has been designed.
Rapid and scalable synthesis of fluoroketones via cerium-mediated C–C bond cleavage
Authors: Lu Yen-Chu , Jordan Helen M. , West Julian G.
Published: January 2021

Ceric ammonium nitrate allows the rapid and scalable synthesis of fluoroketones from cyclobutanols.
Sulfur poisoning of Pt and PtCo anode and cathode catalysts in polymer electrolyte fuel cells studied by operando near ambient pressure hard X-ray photoelectron spectroscopy
Authors: Chaveanghong Suwilai , Nakamura Takahiro , Takagi Yasumasa , Cagnon Benjamin , Uruga Tomoya , Tada Mizuki , Iwasawa Yasuhiro , Yokoyama Toshihiko
Published: January 2021

We have investigated the S adsorption behaviours on Pt and Pt3Co anode and cathode electrode catalysts in PEFC under working conditions for the fresh and degraded states, by studying near ambient pressure HAXPES.
Synchrotron infrared spectroscopic high-throughput screening of multi-composite photocatalyst films for air purification
Authors: Wei Yuxue , Wang Azhu , Lv Lingling , Xu Faqiang , Yang Jie , Cai Mengdie , Cheng Qin , Chen Jingshuai , Bao Jun , Gao Chen , Sun Song
Published: January 2021

Synchrotron-based infrared microscope was used for the high-throughput screening of Fe3+/Nb5+ doped TiO2 photocatalysts for air purification.
A combined experimental and computational study to decipher complexity in the asymmetric hydrogenation of imines with Ru catalysts bearing atropisomerizable ligands
Authors: León Félix , Comas-Vives Aleix , Álvarez Eleuterio , Pizzano Antonio
Published: January 2021

RuCl2(P–OP)(N–N) complexes containing an atropisomerizable phosphine–phosphite and a chiral diamine are effective catalyst precursors for the asymmetric hydrogenation of N-aryl imines following an outer-sphere mechanism.
Highly efficient catalytic transfer hydrogenation of furfural over defect-rich amphoteric ZrO2 with abundant surface acid–base sites
Authors: Zhu Zekun , Yang Lingling , Ke Changxuan , Fan Guoli , Yang Lan , Li Feng
Published: January 2021

The synergistic effect of surface acid–base sites affords a harmonious environment for achieving excellent efficiency for catalytic transfer hydrogenation of furfural.
Ferro-vs.antiferromagnetic exchange between two Ni(ii) ions in a series of Schiff base heterometallic complexes: what makes the difference?
Authors: Vassilyeva Olga Yu. , Buvaylo Elena A. , Kokozay Vladimir N. , Skelton Brian W. , Sobolev Alexandre N. , Bieńko Alina , Ozarowski Andrew
Published: January 2021

Thanks to HFEPR, exchange and dipole–dipole contributions to ZFS characterizing the excited states of the dimers and binuclear cation were determined. The trends ofJandDwere predicted using the DFT “broken symmetry” andab initioCASSCF methods.
Role of the ancillary ligand in controlling the lysozyme affinity and electronic properties of terpyridine fac-Re(CO)3 complexes
Authors: Mansour Ahmed M. , Radacki Krzysztof , Shehab Ola R.
Published: January 2021

Lysozyme had a strong affinity to Re(CO)3+ and the terpyridine ligand can act as a carrier. Exchange of Br− with DMSO is the control factor, which enables the binding to that protein compared to the stable triazolate moiety.
Multifunctional properties of {CuII2LnIII2} systems involving nitrogen-rich nitronyl nitroxide: single-molecule magnet behavior, luminescence, magnetocaloric effects and heat capacity
Authors: Li Hongdao , Jing Pei , Lu Jiao , Xi Lu , Wang Qi , Ding Lifeng , Wang Wen-Min , Song Zhenjun
Published: January 2021

A family of 3d–4f heterometallic ring-shaped clusters on the basis of a nitrogen-rich nitronyl nitroxide radical have been obtained, and they feature polyfunctionality including magnetic properties, thermodynamics and luminescence behavior.
Recent advances in aminative difunctionalization of alkenes
Authors: Wu Ziying , Hu Miao , Li Jianxiao , Wu Wanqing , Jiang Huanfeng
Published: January 2021

This review summarizes recent advances in transition metal-catalyzed or metal-free aminative difunctionalization of alkenes to construct nitrogen-containing compounds.
Direct C2-arylation of N-acyl pyrroles with aryl halides under palladium catalysis
Authors: Chen Weiqiang , Li Hui-Jing , Cheng Yun-Fei , Wu Yan-Chao
Published: January 2021

C2-arylation of N-acyl pyrroles with aryl halides is developed here using Pd(PPh3)4 as a catalyst in combination with Ag2CO3.
Acid-triggering of light-induced charge-separation in hybrid organic/inorganic molecular photoactive dyads for harnessing solar energy
Authors: Benazzi Elisabetta , Karlsson Joshua , Ben M'Barek Youssef , Chabera Pavel , Blanchard Sébastien , Alves Sandra , Proust Anna , Pullerits Tönu , Izzet Guillaume , Gibson Elizabeth A.
Published: January 2021

H+modulated charge-transfer in photoexcited covalently linked W and Mo Keggin-bodipy conjugates is demonstrated using transient absorption spectroscopy and photoluminescence. Adding acid switches on (W) or accelerates (Mo) charge separation.
New triorganotin(iv) compounds with aromatic carboxylate ligands: synthesis and evaluation of the pro-apoptotic mechanism
Authors: Rashid Faisal , Uddin Noor , Ali Saqib , Haider Ali , Tirmizi Syed Ahmad , Diaconescu Paula L. , Iqbal Jamshed
Published: January 2021

Three new organotin(iv) carboxylate compounds were synthesized and structurally characterized by elemental analysis and FT-IR and multinuclear NMR (1H, 13C, 119Sn) spectroscopy.
The influence of the synthesis conditions on the magnetic behaviour of the densely packed arrays of Ni nanowires in porous anodic alumina membranes
Authors: Vorobjova Alla , Tishkevich Daria , Shimanovich Dmitriy , Zubar Tatiana , Astapovich Ksenia , Kozlovskiy Artem , Zdorovets Maxim , Zhaludkevich Aliaksandr , Lyakhov Dmitry , Michels Dominik , Vinnik Denis , Fedosyuk Valery , Trukhanov Alex
Published: January 2021

The densely packed arrays of Ni nanowires of 70 nm diameter and 6–12 μm length were obtained via electrodeposition into porous alumina membranes (PAAMs) of 55–75 μm thickness.
Ozonation enhancement of low cost double-stranded DNA binding dye based fluorescence measurement of total bacterial load in water
Authors: Choi Jiwon , Chua Beelee , Son Ahjeong
Published: January 2021

Principle of ozonation enhanced dsDNA binding dye based fluorescence measurement of total bacterial load in water.
Green thin film for stable electrical switching in a low-cost washable memory device: proof of concept
Authors: Arshad Naila , Irshad Muhammad Sultan , Abbasi Misbah Sehar , Ur Rehman Saif , Ahmed Iftikhar , Javed M. Qasim , Ahmad Shafiq , Sharaf Mohamed , Al Firdausi Muhammad Dzulqarnain
Published: January 2021

Low-cost and washable resistive switching (RS) memory devices with stable retention and low operational voltage are important for resistive random-access memory (RRAM).
Blackening of titanium dioxide nanoparticles by atomic hydrogen and the effect of coexistence of water on the blackening
Authors: Fujimoto Masahide , Matsumoto Masuaki , Nagatsuka Naoki , Fukutani Katsuyuki
Published: January 2021

A fast blackening process of titanium dioxide nanoparticles by exposing to atomic hydrogen was studied by estimating the color of the nanoparticles.
Introduction of a trinuclear manganese(iii) catalyst on the surface of magnetic cellulose as an eco-benign, efficient and reusable novel heterogeneous catalyst for the multi-component synthesis of new derivatives of xanthene
Authors: Ghamari kargar Pouya , Bagherzade Ghodsieh , Eshghi Hossein
Published: January 2021

In this work, the new trinuclear manganese catalyst defined as Fe3O4@NFC@NNSM-Mn(iii) was successfully manufactured and fully characterized by different techniques, including FT-IR, XRD, TEM, SEM, EDX, VSM, and ICP analysis.
Novel triazole derivatives as ecological corrosion inhibitors for mild steel in 1.0 M HCl: experimental & theoretical approach
Authors: Nahlé A. , Salim R. , El Hajjaji F. , Aouad M. R. , Messali M. , Ech-chihbi E. , Hammouti B. , Taleb M.
Published: January 2021

The present paper illustrates the investigation of two novel ecological triazole derivative corrosion inhibitors, namely ethyl 2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetate [Tria-CO2Et], and 2-(4-phenyl-1H-1,2,3-triazol-1-yl) acetohydrazide [Tria-CONHNH2].
DFT calculations for single-atom confinement effects of noble metals on monolayer g-C3N4 for photocatalytic applications
Authors: Yang Cheng , Zhao Zong-Yan , Wei Hai-Tang , Deng Xi-Yu , Liu Qing-Ju
Published: January 2021

Graphitic carbon nitride, as a very promising two-dimensional structure host for single atom catalysts (SACs), has been studied extensively due to its significant confinement effects of single atoms for photocatalytic applications.
Palladium supported on mixed-metal–organic framework (Co–Mn-MOF-74) for efficient catalytic oxidation of CO
Authors: Salama Reda S. , Mannaa Mohammed A. , Altass Hatem M. , Ibrahim Amr Awad , Khder Abd El-Rahman S.
Published: January 2021

Pd nanoparticles were loaded on Cox–Mn(1−x)-MOF-74. 5 wt% Pd@Co0.5–Mn0.5-MOF-74 was the most effective catalyst for CO oxidation. The prepared catalysts displayed excellent stability during CO oxidation without significant decrease in catalytic performance.
Upconversion luminescence and temperature sensing properties of NaGd(WO4)2:Yb3+/Er3+@SiO2 core–shell nanoparticles
Authors: Zheng Lu , Huang Xinyi , Zhong Jiuping , Wang Zijun , Cheng Xiaoning
Published: January 2021

A shell of SiO2 with tunable thickness was uniformly coated on NaGd(WO4)2:Yb3+/Er3+ core upconversion nanoparticles (UCNPs). The effects of the silica shell on UC luminescence and thermal sensing properties of the core–shell UCNPs were investigated.
In silico studies of ASEM analogues targeting α7-nAChR and experimental verification
Authors: Zhou Yang , Kuang Guanglin , Li Junhao , Halldin Christer , Nordberg Agneta , Långström Bengt , Tu Yaoquan , Ågren Hans
Published: January 2021

The in silico binding free energies of the ASEM analogues targeting α7-nAChR are in line with the inhibition obtained from in vitro binding assays.
Design strategies toward transition metal selenide-based catalysts for electrochemical water splitting
Authors: Zeng ChuiTao , Dai Lingyun , Jin YuHong , Liu JingBing , Zhang QianQian , Wang Hao
Published: January 2021

This review focuses on the catalytic mechanism and the modification strategies for Se-based catalysts, including morphological control, anion substitution and cation doping, using composite materials modified by constructing hetero-structures, and their synergistic effects
More than just a barrier: using physical models to couple membrane shape to cell function
Authors: Frey Felix , Idema Timon
Published: January 2021

Physical models can help us to infer, from the shape of the outer membrane, which biological processes happen inside the living cell.
Retraction: Vitexin mitigates myocardial ischemia reperfusion-induced damage by inhibiting excessive autophagy to suppress apoptosis via the PI3K/Akt/mTOR signaling cascade
Authors: Fisher Laura
Published: January 2021

Retraction of ‘Vitexin mitigates myocardial ischemia reperfusion-induced damage by inhibiting excessive autophagy to suppress apoptosis via the PI3K/Akt/mTOR signaling cascade’ by Zhaobin Tang et al., RSC Adv., 2017, 7, 56406–56416, DOI: 10.1039/C7RA12151B.
Retraction: The nuclear export of TR3 mediated gambogic acid-induced apoptosis in cervical cancer cells through mitochondrial dysfunction
Authors: Fisher Laura
Published: January 2021

Retraction of ‘The nuclear export of TR3 mediated gambogic acid-induced apoptosis in cervical cancer cells through mitochondrial dysfunction’ by Chunhong Zhang et al., RSC Adv., 2019, 9, 11855–11864, DOI: 10.1039/C8RA10542A.
Evidence-Based Practice in Speech-Language Pathology: Where Are We Now?
Authors: Greenwell Tamar , Walsh Bridget
Published: January 2021

Purpose

In 2004, American Speech-Language-Hearing Association established its position statement on evidence-based practice (EBP). Since 2008, the Council on Academic Accreditation has required accredited graduate education programs in speech-language pathology to incorporate research methodology and EBP principles into their curricula and clinical practicums. Over the past 15 years, access to EBP resources and employer-led EBP training opportunities have increased. The purpose of this study is to provide an update of how increased exposure to EBP principles affects reported use of EBP and perceived barriers to providing EBP in clinical decision making.

Method

Three hundred seventeen speech-language pathologists completed an online questionnaire querying their perceptions about EBP, use of EBP in clinical practice, and perceived barriers to incorporating EBP. Participants' responses were analyzed using descriptive and inferential statistics. We used multiple linear regression to examine whether years of practice, degree, EBP exposure during graduate program and clinical fellowship (CF), EBP career training, and average barrier score predicted EBP use.

Results

Exposure to EBP in graduate school and during the CF, perception of barriers, and EBP career training significantly predicted the use of EBP in clinical practice. Speech-language pathologists identified the three major components of EBP: client preferences, external evidence, and clinical experience as the most frequently turned to sources of EBP. Inadequate time for research and workload/caseload size remain the most significant barriers to EBP implementation. Respondents who indicated time was a barrier were more likely to cite other barriers to implementing EBP. An increase in EBP career training was associated with a decrease in the perception of time as a barrier.

Conclusions

These findings suggest that explicit training in graduate school and during the CF lays a foundation for EBP principles that is shaped through continued learning opportunities. We documented positive attitudes toward EBP and consistent application of the three components of EBP in clinical practice. Nevertheless, long-standing barriers remain. We suggest that accessible, time-saving resources, a consistent process for posing and answering clinical questions, and on the job support and guidance from employers/organizations are essential to implementing clinical practices that are evidence based. The implications of our findings and suggestions for future research to bridge the research-to-practice gap are discussed.
W‐band TE102‐mode filter with doubly loaded E‐plane and H‐plane irises
Authors: Bartlett Chad , Höft Michael
Published: January 2021

In this correspondence, high‐precision computer numerical control milling is utilised to demonstrate a doubly loaded iris, cross‐coupled waveguide bandpass filter for inline operation within the W‐band. This sixth‐order filter is designed in a stacked H‐plane configuration and utilises both E‐plane and H‐plane doubly loaded irises to maintain the flow of a TE102‐mode electromagnetic field. In this configuration, a high rejection level is maintained outside of the passband while a good unloaded quality factor is obtained through the support of larger resonator dimensions. The filter is designed for approximately 2% fractional bandwidth centred at 97.5 GHz and has been fabricated as three brass components. Measurements of the filter agree very well with the simulated results and demonstrate a spurious‐free design over the full W‐band.
Five‐level class‐D amplifier employing fourth‐order continuous‐time sigma‐delta modulator
Authors: Pakniat Hossein
Published: January 2021

A new closed‐loop multi‐level Class‐D amplifier employing a fourth‐order ‘continuous‐time sigma‐delta modulator’ is proposed and analysed. The proposed amplifier is intrinsically linear and it has approximately the fixed ‘total harmonic distortion plus noise’ against the input frequency. The corresponding circuit is designed and simulated in 180 nm technology (3.3 V), while the post‐layout model of the power stage is employed. A total harmonic distortion plus noise of 0.0016%, the quiescent current of 2.6 mA, the maximum efficiency of 94%, the average switching frequency of 400∼500 kHz and an excellent ‘power supply reject ration’ of 120 dB are achieved.
Demonstration of a 20‐W membrane‐external‐cavity surface‐emitting laser for sodium guide star applications
Authors: Priante D. , Zhang M. , Albrecht A.R. , Bek R. , Zimmer M. , Nguyen C. , Follman D. , Cole G.D. , Sheik‐Bahae M.
Published: January 2021

We present a record 20‐W continuous‐wave output power membrane‐external‐cavity surface‐emitting laser (MECSEL) double‐bonded to silicon carbide (SiC) heat spreaders emitting around 1178 nm. We achieved a maximum slope efficiency of 27.7% and an optical‐to‐optical efficiency of 26.7%. By utilising an intracavity birefringent filtre, the wavelength was tuned over 75 nm and maximum output power of 12.7 W was recorded at 1178 nm. This study shows the potential of MECSELs to achieve high‐performance and cost‐effective optically pumped semiconductor disk lasers targeting applications in sodium guide stars.
Enhancement of sensing range of Brillouin optical time‐domain reflectometry system up to 150 km with in‐line bi‐directional erbium‐doped fibre amplifications
Authors: Clement Pierre , Gabet Renaud , Lanticq Vincent , Jaouën Yves
Published: January 2021

Brillouin optical time‐domain reflectometry (BOTDR) has the advantage of requiring access to only one end of the sensing fibre, which is an important property for some applications. The coherent detection of spontaneous Brillouin scattering allows high sensitivity of temperature/strain measurements, close to one of the well‐known Brillouin optical time‐domain analyser‐based solutions. In‐line amplification based on bidirectional erbium‐doped fibre amplification (EDFA) modules can improve sensing distance and temperature accuracy. This study demonstrates a distributed sensing over 150 km with 5‐m spatial resolution and a temperature error of less than 2°C in 10 min without requiring specific BOTDR adaptation. A record performance of 0.7°C in 60 min has been also obtained, which corresponds to the best performance obtained in reflectometer configuration at this distance.
Dynamic optimized cooperation in multi‐source multi‐relay wireless networks with random linear network coding
Authors: Benamira E. , Merazka F. , Kurt G. K.
Published: January 2021

The authors present a strategy that improves the reliability of data transmission from multiple sources towards a destination D via multiple relays over wireless channels. After the broadcast phase, the destination selects the best cooperative direct link sources with the highest instantaneous signal‐to‐noise ratio , then generates and sends the random linear network coding coefficient matrix to the relays. After receiving the random linear network coding–coded symbols (packets) from the relays, D completes the reception and decoding of all source nodes packets. Monte Carlo simulations are conducted with Galois field (GF) () symbols ( = 2, 4 and 8) and the results are compared with the scenario of static cooperative direct links. An important decrease of symbol error rate (SER) is achieved. Furthermore, the efficiency of this approach is confirmed for the whole range of possible values of path loss exponent on direct links, that is, all types of environment between source nodes and destination D.
Critical frequency of metasurfaces on dielectric half‐space
Authors: Liu Xiaobo , Chen Xiaoming , Zhang Anxue , Kishk Ahmed A.
Published: January 2021

In this letter, the critical frequency of the periodic metasurface in a dielectric half‐space is studied. First, according to the mode expansion theory, the wave of the periodic metallic elements can be decomposed into different eigen‐modes. Then, as the frequency increases, partial high‐order modes are excited by the periodic metallic elements that may propagate into the substrates as spics. Finally, the critical frequency is analytically derived for a homogenized surface without spics. This study shows that the reflected and transmitted spics can co‐exist, but there is a distinct difference between their corresponding critical frequencies. Thus, the actual critical frequency of homogenized metasurface in a dielectric half‐space is not only related to the periodicity and incident angle, but also to the substrates.
Electrocardiogram estimation using Lagrange interpolation
Authors: Yadav Om Prakash , Sahu Anil Kumar
Published: January 2021

An electrocardiogram records activity of cardiac which is collected through the electrodes positioned on specific locations on the human body. These signals are required for cardiac‐related issues. Electrocardiogram signals are quasi‐stable signals and are often contaminated by artefacts. The magnitude and frequency of these artefacts are different, and thus their effect on electrocardiogram is also variable. These artefacts must reduce to a significantly optimum level to make them interpretable. This paper proposes an algorithm to estimate electrocardiogram signals from the MIT‐BIH database signal using Lagrange interpolation through Chebyshev nodes. The performance evaluation of the proposed method has been assessed through standard estimation tools. Performance parameters revealed that the algorithm is suitable for signal estimation irrespective of the characteristic of artefact introduced to the signal.
Efficient and robust bitstream processing in binarised neural networks
Authors: Aygun Sercan , Gunes Ece Olcay , De Vleeschouwer Christophe
Published: January 2021

In the neural network context, used in a variety of applications, binarised networks, which describe both weights and activations as single‐bit binary values, provide computationally attractive solutions. A lightweight binarised neural network system can be constructed using only logic gates and counters together with a two‐valued activation function unit. However, binarised neural networks represent the weights and the neuron outputs with only one bit, making them sensitive to bit‐flipping errors. Binarised weights and neurons are manipulated by the utilisation of bitstream processing with regard to stochastic computing to cope with this error sensitivity. Stochastic computing is shown to provide robustness for bit errors on data while being built on a hardware structure, whose implementation is simplified by a novel subtraction‐free implementation of the neuron activation.
Millimetre‐wave high–low IMPATT source development: First on‐chip experimental verification
Authors: Mukherjee Moumita , Chatterjee Sulagna
Published: January 2021

This paper reports design and development of high–low type Si/SiC‐based Impact Ionisation Avalanche Transit Time device and its on‐chip characterisation. The design has been performed with indigenously developed strain engineered non‐linear self‐consistent large‐signal simulator. On‐chip hetero‐structure SiC Impact Ionisation Avalanche Transit Time at 94 GHz has been successfully fabricated and on‐chip DC testing (forward and reverse) results are reported for the first time. The device breaks down at 185 V (simulated result: 188 V) and breakdown current is ∼12.5 mA. If the diode chip is mounted properly with W‐band waveguide, it is expected to generate ∼2 W of Radio Frequency (RF) power at W‐band window frequency (∼94 GHz). The experimental verification of newly developed in‐house strain‐corrected mixed quantum tunnelling drift diffusion simulator is done successfully.
Deep learning‐based massive multiple‐input multiple‐output channel state information feedback with data normalisation using clipping
Authors: Jo Sanguk , Lee Jaehee , So Jaewoo
Published: January 2021

Massive multiple‐input multiple‐output (MIMO) can provide real‐time high‐capacity data transmission service to the user equipment (UE). However, the use of massive MIMO exponentially increases the channel state information (CSI) feedback overhead. Deep learning‐based approaches have been proposed to reduce CSI feedback overhead with significant CSI accuracy. Data normalisation is a very important part of deep learning, because the performance of the deep learning highly depends on the data normalisation. In this letter, an efficient data normalisation method for deep learning‐based CSI feedback in a massive MIMO system is proposed, where the proposed method uses a clipping technique based on the received signal strength. Simulation results show that the proposed normalisation with the clipping decreases the CSI feedback error and increases the accuracy of the beamforming vector in deep learning‐based CSI feedback.
Ultra‐wideband and large‐range incident angles radar cross‐section reduction by quasi‐fractal polarisation conversion metasurfaces
Authors: Shakouri Amir Hossein , Ameri Edris , Sedighy Seyed Hassan
Published: January 2021

This study proposes a quasi‐fractal polarisation conversion metasurface (PCM) for ultra‐wideband radar cross‐section reduction (RCSR). The simple and proposed metasurface is composed of double‐heads arrowed‐like unit cell benefited from the second iteration Koch fractal in its arm and cut‐line to broaden the bandwidth. Consequently, this PCM unit cell and its 90, 180 and 270 degrees rotated counterparts obtain destructive interference cancellation between their reflected waves and RCSR. The proposed metasurface demonstrates 10‐dB RCSR from 7.68 to 40.87 GHz (136.73%) for normal incident waves, and more than 96.7% up to 40 degrees incident angle that verifies the large range incident angle RCSR of the surface. The experimental measurement results at the normal incident angle and their comparison with simulation ones prove the idea.
Towards fully domain‐independent gesture recognition using COTS WiFi device
Authors: Yin Yuqing , Zhang Zixin , Yang Xu , Yan Faren , Niu Qiang
Published: January 2021

This letter proposes a fully domain‐independent WiFi‐based gesture recognition system based on the multi‐label adversarial network. Unlike pioneer machine learning works, our system does not require retraining in the target domain, which benefits from our key idea of eliminating fully domain information such as orientations, locations, environment information. The system proposed by us includes three parts: Feature extractor, domain discriminator, and gesture recogniser. The feature extractor attempts to deceive the domain discriminator based on the adversarial network structure so that it is difficult to judge the input domain label, thereby obtaining domain‐independent features and realising fully domain‐independent gesture recognition. Extensive experiments are conducted on the Widar 3.0 dataset and our dataset to evaluate system performance. The results show that our system can achieve an in‐domain recognition accuracy of 93.2% and a cross‐domain recognition accuracy of 87.1%, which is superior to other state‐of‐the‐art works.
Performance analysis of a novel outer rotor flux‐switching permanent magnet machine as motor/generator for vehicular and aircraft applications
Authors: Sharouni Sahar , Naderi Peyman , Hedayati Mahdi , Hajihosseini Payman
Published: January 2021

Herein, a novel study on outer rotor flux‐switching permanent magnet (OR‐FSPM) machines for motor/generator applications is presented. An improved magnetic equivalent circuit (MEC) is used for saturable machine model, and the performance analysis is presented in both dynamic and steady‐state cases. A flexible MEC‐based method is used, where the machines with arbitrary properties can be analysed. Moreover, the model accuracy can be tuned by selective parameters in the proposed method. It is shown that the machine can be used as a high efficiency 400 Hz Ground Power Unit (GPU) for aircraft application. Furthermore, the machine usage for in‐wheel application in the hybrid and electric vehicles (HVs and EVs) is analysed. Comparison with 2D and 3D finite‐element‐method (FEM) shows the effectiveness and accuracy of the proposed MEC method, where shorter processing time is obtained compared with FEM.
Modelling of magnetostrictive vibration and acoustics in converter transformer
Authors: Yadav Suman , Mehta Ram Krishna
Published: January 2021

The converter transformers are susceptible to more noise and vibration when compared to power transformers due to the presence of DC bias in the DC transmission line. DC bias occurs mostly due to inaccuracies in valve firing resulting in a small residual DC oscillating around zero. Measurement of magnetostriction becomes significant as it influences the vibration and noise from the core. Hence, a magnetostrictive model of a high‐voltage DC converter transformer has been developed. This work analyses the vibration and noise acoustics under such an occurrence. First, the core of the transformer model is designed in the stepped configuration for 240 MVA; then, magnetostrictive vibration is analysed by using suitable modules of COMSOL Multiphysics at different magnitudes of DC bias. The physics of noise has been interfaced using the Acoustics Module, and the results are recorded. Finally, artificial neural network model is developed for the prediction of vibration and noise characteristics of the model. The fitting process of neural network was then remodelled using various optimisation techniques, namely teaching–learning‐based optimisation, particle swarm optimisation, biogeography‐based optimisation, simulated annealing and binary coded genetic algorithm, and their results were compared to obtain the best‐suited method using % mean‐squared‐error evaluation.
Utilising LiDAR for fall detection
Authors: Frøvik Nikolai , Malekzai Bashir A. , Øvsthus Knut
Published: January 2021

Autonomous driving generates several low‐cost technologies, such as light detection and ranging (LiDAR). Due to this, the LiDAR technology has experienced impressive performance improvements. Our ambition is to capitalise on this development, where LiDAR is considered as the enabling technology for a non‐invasive monitoring system for securing elder persons in their home. A motivation for technology‐based securing of elder persons is that many countries experience a demographic change. Traditional personal care by care worker or re‐location to special homes of elder persons does not scale due to the shrinking fraction of the working population. Technology can reduce some of the burden. This article proposes and assesses technology for securing a person's home. However, securing a person, based on monitoring, requires careful design because the technology should be non‐invasive, reliable and low cost. LiDAR technology offers several crucial qualities that meet these system requirements. This article provides a proof of concept for a low‐cost, non‐invasive LiDAR‐based monitoring system. Our proposed system can detect if a person has fallen, and it can trigger an alarm to the care services when required. We emphasise especially that our monitoring solution can operate in the bathroom and even in the shower.
Robustness evaluation of an inkjet‐printed epidermal ultra‐high‐frequency radio frequency identification tag
Authors: Oyeka Dumtoochukwu Obiora , Batchelor John C.
Published: January 2021

This paper examines the impact of daily activities on the performance of a body‐mounted radio frequency identification (RFID) tag inkjet printed onto tattoo transfer paper. This paper aims to assess how robust RFID tags of this nature are when mounted on the skin while the user undergoes various daily activities. The factors considered for these robustness tests are the effect of sweat and wear and tear on these tags during everyday use and also how it stands up to being exposed to water and soap during showering. Performance assessment was carried out using parameters such as point‐to‐point surface DC resistance as well as read range. Results show marginal effects on the tag performance and the tag continued to function during a normal day's activities, which lasted for 8 h, and rigorous activities like exercising but stopped functioning when there was severe damage to tag.
A mild route for the preparation of calcium carbonate rod bundles in large scale from carbide slag
Authors: Yang Baojun , Shao Zongqi , Zhang Dongxue , Wang Bainian
Published: January 2021

In this article, a powerful method to synthesize uniform CaCO3 rod bundles with a high mass fraction of aragonite from carbide slag in large‐scale production via a two‐step leaching‐precipitation process is reported. The effects of the addition of ethylene glycol and reaction temperature on the structure and morphology of the prepared CaCO3 samples were investigated and then demonstrated by the experimental results. It is beneficial to increase the mass fraction of aragonite in CaCO3 samples and ensure the formation of regular rod bundles in morphology when the addition of ethylene glycol is 30 mL and the reaction temperature is 80 °C. The formation mechanism of the CaCO3 rod bundles was preliminarily discussed according to the Muffins–Sekerka theory.
Concurrent photocatalytic degradation and filtration with bi‐plasmonic TiO2 for wastewater treatment
Authors: Anvari Abbas , Amoli‐Diva Mitra , Sadighi‐Bonabi Rasoul
Published: January 2021

A new photocatalytic filtration membrane was prepared by grafting of Ag–Au bi‐plasmonic shell‐on TiO2@Fe3O4 nanoparticles as a magnetically‐separable heterogeneous photocatalyst to a poly acrylic acid‐modified cellulose acetate membrane for decomposition and removal of methyl orange as a model pollutant from textile wastewater samples. Eight photocatalysts including five Au NPs‐modified TiO2@Fe3O4 NPs and three Ag‐Au bi‐plasmonic NPs‐decorated TiO2@Fe3O4 NPs with different shell thickness were synthesized and characterized by TEM, UV–vis, and SEM techniques and their photocatalytic activity was assessed using two radiation sources. After selection of optimum photocatalyst and modification of cellulose acetate membrane, the photodegradation of methyl orange was evaluated in a dead‐end membrane reactor using the prepared membrane. The flux performance, antifouling property and pollutant removal efficiency of the membrane were evaluated using textile wastewater samples. It was demonstrated that the prepared membrane reactor is able to produce cleaner water with more stable flux performance and good antifouling property.
Nanomechanical characterisation of single‐crystal Bi2Se3 topological insulator
Authors: Uzun Utku , Yetmez Mehmet , Akıncı Nurgül
Published: January 2021

Topological insulators (TIs) are recently discovered high‐tech materials where their potential use in nanoelectronic devices such as spintronics and quantum computers, due to their unique electronic features, can be a solution to the emerging need for high‐bit data processing. Yet their mechanical properties are not well understood for their use in practical applications. With the objective of exploiting the nanomechanical behaviour of TIs, bulk single‐crystal Bi2Se3 TI is grown by using the Bridgeman–Stockbarger method and mechanically characterised by the nanoindentation method. The Young's modulus and hardness were extracted from the load‐displacement data by using Oliver and Pharr's standard method. Further, fracture toughness of the material was reported for the first time after comprehensive research of indentation crack length (ICL) methods. The grown Bi2Se3 exhibits hardness and Young's modulus as 323 MPa and 6.018 GPa at nanoscale, respectively. Fracture toughness of the TI was evaluated at 0.034 MPa m1/2 and elastic recovery was around 60% after the full unloading process.
A molecular dynamics study of the effect of nanoparticles coating on thermal conductivity of nanofluids
Authors: Roni Md. Rakibul Hasan , Shahadat Muhammad Rubayat Bin , Morshed A.K.M. Monjur Monjur
Published: January 2021

Nanofluids have become the subject of theoretical and experimental researches over the last few decades due to their enhanced heat transfer performance. In this study, thermal conductivity of copper argon nanofluids containing coated and non‐coated copper particles is determined through MD simulation. Coating over the nanoparticles is applied to provide long‐term stable dispersion and also to enhance the heat transfer performance. Thermal conductivity of nanofluids depends on the types of coating applied over the nanoparticles. The role of surface coating over the nanoparticles in enhancing thermal properties of the nanofluids is discussed and compared to that of non‐coated particles. The silver coating is applied over the copper nanoparticles. Green Kubo method is employed to determine the thermal conductivity of the nanofluids. Result shows that, for volume fraction 3% and 86 K system temperature, thermal conductivity enhancement of nanofluid containing coated particle is 17% compared to that of base fluid and without coating, thermal conductivity enhancement is 12%. The mechanism of increased heat transfer performance for surface coating over the nanoparticles is discussed in this paper.
Design and analysis of piezoelectric MEMS micro‐speaker based on scandium‐doped AlN thin film
Authors: Fawzy Ahmed , Lang Yiming , Zhang Menglun
Published: January 2021

Piezoelectric MEMS microspeakers are promising candidates for miniaturized speakers, such as for in‐ear applications. Using lead‐free scandium doped aluminium nitride (ScAlN) thin film instead of lead zirconium titanate helps these speakers to be environmental friendly, CMOS compatible and potentially more linear. The piezoelectric coefficient of ScAlN is higher than undoped AlN, which leads to improved performance of MEMS actuators including speaker chips. The design of piezoelectric MEMS ScAlN speaker based on four triangular cantilevers is proposed. The design in this work has been verified by finite element method simulation. The displacement and sound pressure level are 39 μm and 56 dB, respectively. This MEMS loudspeaker has small size and simple structure. The model opens the door also to further optimization for higher energy efficiency and higher acoustic performance based on lead‐free ScAlN thin film.