bluuebunny/crossref_metadata_2025 huggingface dataset:
Kirigami electrodes of conducting polymer nanofibers for wearable humidity dosimeters and stretchable supercapacitors
Authors: Diao Yifan , Woon Reagan , Yang Haoru , Chow Alina , Wang Hongmin , Lu Yang , D'Arcy Julio M.
Published: March 2021

Nanofibrillar Kirigami electrodes enable superior sensitivity in humidity sensors and state-of-the-art energy density in supercapacitors.
Polyvinyl alcohol/chitosan composite hydrogels with sustained release of traditional Tibetan medicine for promoting chronic diabetic wound healing
Authors: Wang Zuxin , Gao Shan , Zhang Wanlin , Gong Hanwen , Xu Kai , Luo Chao , Zhi Wei , Chen Xingyu , Li Jianshu , Weng Jie
Published: March 2021

TEP were loaded into the PVA/CS hydrogel to treat diabetic wounds by slowly releasing the active ingredients of TEP, which has changed the traditional TEP administration method for skin repair.
Highly efficient oxidation of 2,2′-hydrazobis-isobutyronitrile to 2,2′-azobis-isobutyronitrile over a CrOx/TiO2 catalyst with hydrogen peroxide
Authors: Zhang Hu , Yue Shengnan , Zou Xiujing , Wang Xueguang , Zou Xingli , Lu Xionggang
Published: March 2021

A green and recyclable heterogeneous CrOx/TiO2 catalyst was developed for highly efficient oxidation of 2,2′-hydrazobis-isobutyronitrile to 2,2′-azobis-isobutyronitrile with hydrogen peroxide under mild conditions.
Synthesis of 2-isoxazolyl-2,3-dihydrobenzofurans via palladium-catalyzed cascade cyclization of alkenyl ethers
Authors: Zhou Fei , Li Can , Li Meng , Jin Yangbin , Jiang Huanfeng , Zhang Yingjun , Wu Wanqing
Published: March 2021

An efficient palladium-catalyzed cascade cyclization reaction of alkenyl ethers with alkynyl oxime ethers for the construction of poly-heterocyclic scaffolds has been developed.
A targeted covalent small molecule inhibitor of HIV-1 fusion
Authors: Zhou Guangyan , He Li , Li Kathy H. , Pedroso Cássio C. S. , Gochin Miriam
Published: March 2021

Formation of a covalent bond with a conserved lysine in the hydrophobic pocket of HIV-1 gp41 boosted antiviral activity of a small molecule inhibitor.
Computational predictions of metal–macrocycle stability constants require accurate treatments of local solvent and pH effects
Authors: Gentry Brian M. , Choi Tae Hoon , Belfield William S. , Keith John A.
Published: March 2021

Benchmarking quantum chemistry calculation schemes for accurate predictions of absolute stability constants of metal–macrocycle complexes.
Carbothermally generated copper–molybdenum carbide supported on graphite for the CO2 hydrogenation to methanol
Authors: Dongil A. B. , Conesa J. M. , Pastor-Pérez L. , Sepúlveda-Escribano A. , Guerrero-Ruiz A. , Rodríguez-Ramos I.
Published: March 2021

The carbothermal synthesis of monometallic and bimetallic molybdenum carbide and copper supported on high surface area graphite, has been studied at 600 and 700 °C and characterised. The catalysts were tested for CO2 hydrogenation to CH3OH.
Food-grade titanium dioxide particles decrease the bioaccessibility of iron released from spinach leaves in simulated human gastrointestinal tract
Authors: Li Chunyang , Ma Chuanxin , Shang Heping , White Jason C. , McClements David Julian , Xing Baoshan
Published: March 2021

E171 reduced Fe bioaccessibility of spinach in a simulated gastrointestinal tractviatwo mechanisms: the inhibition of α-amylase activity and adsorption of released Fe from spinach.
A Z-scheme heterostructure constructed from ZnS nanospheres and Ni(OH)2 nanosheets to enhance the photocatalytic hydrogen evolution
Authors: Liu Ye , Sun Yanpu , Xu Jing , Mao Min , Li Xuanhao
Published: March 2021

ZnS and Ni(OH)2 form a Z-scheme heterostructure, and the synergy between them provides a new hydrogen-producing active center for each material.
The design of an inner-motile waste-energy-driven piezoelectric catalytic system
Authors: Peng Fengping , Xu Wanxin , Hu Yunya , Fu Weijie , Li Haozhen , Lin Jingyuan , Xiao Yafeng , Wu Zhe , Wang Wei , Lu Chunhua
Published: March 2021

A kind of waste-energy-driven catalytic system was explored for the first time using magnetically actuated artificial cilia.
Recent advances in electrochemically driven radical fluorination and fluoroalkylation
Authors: Zou Zhenlei , Zhang Weigang , Wang Yi , Pan Yi
Published: March 2021

Electrochemical fluorination (ECF) refers to the introduction of fluorine-containing moieties into organic molecules under electrochemical conditions.
Rh(iii)-Catalyzed Csp2–Csp3bond alkoxylation of α-indolyl alcoholsviaC–C σ bond cleavage
Authors: Yang Can , Liu Zhipeng , Hu Xinwei , Xie Haisheng , Jiang Huanfeng , Zeng Wei
Published: March 2021

A Rh(iii)-catalyzed direct Csp2–Csp3bond alkoxylation of α-(2-indolyl)alcohols with alcohols has been achievedviaC–C sigma bond/C–O single bond switch.
Nickel-catalyzed reductive benzylation of tertiary alkyl halides with benzyl chlorides and chloroformates
Authors: Wang Jiabao , Gong Yuxin , Sun Deli , Gong Hegui
Published: March 2021

We report a Ni-catalyzed cross-electrophile coupling of benzyl chlorides and chloroformates with unactivated tertiary alkyl halides to forge the challenging benzylated all C(sp3)-quaternary carbon centers.
Strategies towards endo-type B polycyclic polyprenylated acylphloroglucinols: total synthesis of regio-hyperibone L and (+)-epi-clusianone
Authors: Wang Liping , Wang Xueying , Zhang Guocai , Fu Wenwei , Zhang Hong , Zhou Hua , Xu Hongxi , Zheng Changwu
Published: March 2021

The first and general method for the total synthesis of regio-hyperibone L and (+)-epi-clusianone via domino Dieckmann cyclization was developed.
Visible light-promoted NH-halogenation of sulfoximines with dichloromethane or dibromomethane
Authors: Wang Chenyang , Shi Peng , Bolm Carsten
Published: March 2021

In the presence of a hypervalent iodine reagent, N-halo sulfoximines are obtained by catalyst-free visible light-promoted halogenations of their NH-counterparts with dichloro- or dibromomethane as halogen source.
Facile construction of a family of supramolecular gels with good levofloxacin hydrochloride loading capacity
Authors: Chen Renyuan , Xu Caidie , Lei Yihao , Liu Hongxin , Zhu Yabin , Zhang Jianfeng , Xu Long
Published: March 2021

A family of low molecular weight gelators with different alkyl chain lengths was constructed, having excellent gelation ability and antibiotic loading capacity. A low molecular weight hydrogelator was obtained by adjusting the length of alkyl chain.
Bimetallic cobalt–iron diselenide nanorod modified glassy carbon electrode: an electrochemical sensing platform for the selective detection of isoniazid
Authors: Sultan Sundas , Zulqarnain Muhammad , Shah Afzal , Firdous Naveeda , Nisar Jan , Ashiq Muhammad Naeem , Bakhsh Esraa M. , Khan Sher Bahadar
Published: March 2021

FeCoSe2bimetallic nanorods were synthesized by hydrothermal method. The modified electrode responded excellently towards isoniazid detection with LOD of 1.24 × 10−10M. FeCoSe2/GCE showed applicability for INZ detection in real samples.
A straight, open and macro-porous fuel electrode-supported protonic ceramic electrochemical cell
Authors: Pan Yuxin , Pei Kai , Zhou Yucun , Liu Tong , Liu Meilin , Chen Yu
Published: March 2021

A straight, open and macro-porous Ni–BaZr0.1Ce0.7Y0.1Yb0.1O3 fuel electrode-supported protonic ceramic electrochemical cell has been fabricated by a modified phase-inversion method.
A sensitive and rapid detection of glutathione based on a fluorescence-enhanced “turn-on” strategy
Authors: Ma Qianru , Wang Minning , Cai Huahuan , Li Fulai , Fu Songsen , Liu Yan , Zhao Yufen
Published: March 2021

Fabrication of Au@PLL-AEDP-FITC and its response to GSH.
Flexible random resistive access memory devices with ferrocene–rGO nanocomposites for artificial synapses
Authors: Zhou Jiankui , Feng Hanfang , Wang Yadong , Sun Qingqing , Liu Yingliang , Liu Xuying , Zhang Li , Cao Shaokui
Published: March 2021

Flexible RRAM devices based on redox active ferrocene–rGO nanocomposites exhibit an enhanced ON/OFF ratio of 108 and synapse simulations simultaneously.
Triphenylamine/benzothiadiazole-based compounds for non-doped orange and red fluorescent OLEDs with high efficiencies and low efficiency roll-off
Authors: Zhang Di , Yang Tingting , Xu Huixia , Miao Yanqin , Chen Runfeng , Shinar Ruth , Shinar Joseph , Wang Hua , Xu Bingshe , Yu Junsheng
Published: March 2021

Orange and red light-emitting materials were successfully obtained by linking TPA, BT and AN. Owing to their AIE features, the performances of non-doped devices are superior to those of the doped ones.
Correlation between ion gel characteristics and performance of ionic pressure sensors
Authors: Lee Woo Young , Kim Yong Min , Kwon Jin Han , Moon Hong Chul
Published: March 2021

In this study, a convenient approach is proposed to tune the properties of ion gels by utilizing mixed ionic liquid (IL) systems.
Electrically conductive covalent organic frameworks: bridging the fields of organic metals and 2D materials
Authors: Souto Manuel , Perepichka Dmitrii F.
Published: March 2021

We discuss the recent advances and main approaches towards the design of electrically conductive COFs, highlight some of the challenges in such design and give our views on the future directions of this field.
Synthesis and physical properties of single-crystalline InTe: towards high thermoelectric performance
Authors: Misra Shantanu , Levinský Petr , Dauscher Anne , Medjahdi Ghouti , Hejtmánek Jiří , Malaman Bernard , Snyder G. Jeffrey , Lenoir Bertrand , Candolfi Christophe
Published: March 2021

The growth of large single crystals of InTe enables the first detailed study of its basic thermoelectric properties.
Synergy and allostery in ligand binding by HIV-1 Nef
Authors: Aldehaiman Abdullah , Momin Afaque A. , Restouin Audrey , Wang Luyao , Shi Xiaoli , Aljedani Safia , Opi Sandrine , Lugari Adrien , Shahul Hameed Umar F. , Ponchon Luc , Morelli Xavier , Huang Mingdong , Dumas Christian , Collette Yves , Arold Stefan T.
Published: March 2021

The Nef protein of human and simian immunodeficiency viruses boosts viral pathogenicity through its interactions with host cell proteins. By combining the polyvalency of its large unstructured regions with the binding selectivity and strength of its folded core domain, Nef can associate with many different host cell proteins, thereby disrupting their functions. For example, the combination of a linear proline-rich motif and hydrophobic core domain surface allows Nef to bind tightly and specifically to SH3 domains of Src family kinases. We investigated whether the interplay between Nef's flexible regions and its core domain could allosterically influence ligand selection. We found that the flexible regions can associate with the core domain in different ways, producing distinct conformational states that alter the way in which Nef selects for SH3 domains and exposes some of its binding motifs. The ensuing crosstalk between ligands might promote functionally coherent Nef-bound protein ensembles by synergizing certain subsets of ligands while excluding others. We also combined proteomic and bioinformatics analyses to identify human proteins that select SH3 domains in the same way as Nef. We found that only 3% of clones from a whole-human fetal library displayed Nef-like SH3 selectivity. However, in most cases, this selectivity appears to be achieved by a canonical linear interaction rather than by a Nef-like ‘tertiary' interaction. Our analysis supports the contention that Nef's mode of hijacking SH3 domains is a virus-specific adaptation with no or very few cellular counterparts. Thus, the Nef tertiary binding surface is a promising virus-specific drug target.
Processing of Code-Switched Sentences in Noise by Bilingual Children
Authors: Gross Megan C. , Patel Haliee , Kaushanskaya Margarita
Published: March 2021

Purpose

The purpose of the current study was to examine the effects of code-switching on bilingual children's online processing and offline comprehension of sentences in the presence of noise. In addition, the study examined individual differences in language ability and cognitive control skills as moderators of children's ability to process code-switched sentences in noise.

Method

The participants were 50 Spanish–English bilingual children, ages 7;0–11;8 (years;months). Children completed an auditory moving window task to examine whether they processed sentences with code-switching more slowly and less accurately than single-language sentences in the presence of noise. They completed the Dimensional Change Card Sort task to index cognitive control and standardized language measures in English and Spanish to index relative language dominance and overall language ability.

Results

Children were significantly less accurate in answering offline comprehension questions about code-switched sentences presented in noise compared to single-language sentences, especially for their dominant language. They also tended to exhibit slower processing speed, but costs did not reach significance. Language ability had an overall effect on offline comprehension but did not moderate the effects of code-switching. Cognitive control moderated the extent to which offline comprehension costs were affected by language dominance.

Conclusions

The findings of the current study suggest that code-switching, especially in the presence of background noise, may place additional demands on children's ability to comprehend sentences. However, it may be the processing of the nondominant language, rather than code-switching per se, that is especially difficult in the presence of noise.
Changes in Relative Fundamental Frequency Under Increased Cognitive Load in Individuals With Healthy Voices
Authors: Dahl Kimberly L. , Stepp Cara E.
Published: March 2021

Purpose

The purpose of this study was to determine the effect of cognitive load on relative fundamental frequency (RFF) in individuals with healthy voices.

Method

Twenty adults with healthy voices read sentences under different cognitive load conditions. Each sentence contained color terms printed in colored ink, creating an embedded Stroop task. Participants read the ink color in which a word was printed, rather than the color term itself. Sentences with mismatched ink colors and printed words constituted an increased cognitive load. RFF, an acoustic correlate of laryngeal tension, was calculated for the 10 voicing cycles preceding (i.e., offset) and following (i.e., onset) voiceless consonants. Repeated measures analyses of variance were constructed to assess the effects of RFF cycle, cognitive load, and their interaction on mean RFF offset and onset.

Results

There was a significant effect of cognitive load condition on RFF offset. There was no significant effect of condition on RFF onset nor significant interaction between cycle and condition on RFF onset or offset values.

Conclusion

Reduced mean RFF offset may indicate an increase in laryngeal muscle tension during a cognitively demanding task.
Why AI still doesn’t have consciousness?
Authors: Li Deyi , He Wen , Guo Yike
Published: March 2021

Consciousness is one of the unique features of creatures, and is also the root of biological intelligence. Up to now, all machines and robots haven’t had consciousness. Then, will the artificial intelligence (AI) be conscious? Will robots have real intelligence without consciousness? The most primitive consciousness is the perception and expression of self‐existence. In order to perceive the existence of the concept of ‘I’, a creature must first have a perceivable boundary such as skin to separate ‘I’ from ‘non‐I’. For robots, to have the self‐awareness, they also need to be wrapped by a similar sensory membrane. Nowadays, as intelligent tools, AI systems should also be regarded as the external extension of human intelligence. These tools are unconscious. The development of AI shows that intelligence can exist without consciousness. When human beings enter into the era of life intelligence from AI, it is not the AI became conscious, but that conscious lives will have strong AI. Therefore, it becomes more necessary to be careful on applying AI to living creatures, even to those lower‐level animals with only consciousness. The subversive revolution of such application may produce more careful thinking.
A predictive control method to improve pressure tracking precision and reduce valve switching for pneumatic brake systems
Authors: Zhang Rui , Peng Jun , Li Heng , Chen Bin , Liu Weirong , Huang Zhiwu , Wang Jing
Published: March 2021

Pneumatic brake systems are crucial for the operation of trains. However, due to switching characteristics of on/off solenoid valves, the precise pressure control and low switching activities of valves are difficult to guarantee simultaneously during braking. To address the issue, a hybrid model predictive control (MPC) method is proposed for implementing the multi‐objective optimisation in this paper, i.e. the precise pressure tracking and the valve switching reduction. In order to model the hybrid behaviour caused by continuous dynamics of the pressure and discrete features of solenoid valves, the mixed logic dynamical system theory is applied. Then, the braking control problem is recast as a hybrid MPC problem, which jointly optimises the pressure tracking precision and the valve switching. A mixed integer linear program is formulated to solve the MPC problem in an efficient way. Both simulation and experiment results show that the accurate pressure control and low switching activities of valves can be achieved by the proposed method when compared with existing methods.
Micro‐expression recognition by two‐stream difference network
Authors: Pan Hang , Xie Lun , Li Juan , Lv Zeping , Wang Zhiliang
Published: March 2021

Facial micro‐expression is a superposition of micro‐expression features and identity information of a subject. For the problem of identity information interference in micro‐expression recognition, this study proposes a new method for facial micro‐expression recognition by de‐identity information, called two‐stream difference network (TSDN). First, a two‐stream encoder‐decoder network is trained by a convolutional neural network, where the input of the micro‐expression stream is a micro‐expression image, and the identity stream is a facial identity image. The micro‐expression image is the apex image, and the identity image is the onset image in the micro‐expression sequence. The identity information and micro‐expression features are recorded in the intermediate layer of the micro‐expression stream, while the intermediate layer of the identity stream contains only the identity information of a subject. Then, the identity information is removed by the difference network, but micro‐expression features are stored in the intermediate layer of the micro‐expression stream. Given the sequence of the micro‐expressions, the TSDN model of de‐identity information learns the difference that stores in the expression stream. Two public spontaneous facial micro‐expression data sets (SMIC and CASME II) are employed in our experiments. The experiment results show that our model can achieve a superior performance in micro‐expression recognition.
Pop‐net: A self‐growth network for popping out the salient object in videos
Authors: Yin Hui , Chen Ning , Yang Lin , Wan Jin
Published: March 2021

It is a big challenge for unsupervised video segmentation without any object annotation or prior knowledge. In this article, we formulate a completely unsupervised video object segmentation network which can pop out the most salient object in an input video by self‐growth, called Pop‐Net. Specifically, in this article, a novel self‐growth strategy which helps a base segmentation network to gradually grow to stick out the salient object as the video goes on, is introduced. To solve the sample generation problem for the unsupervised method, the sample generation module which fuses the appearance and motion saliency is proposed. Furthermore, the proposed sample optimization module improves the samples by using contour constrains for each self‐growth step. Experimental results on several datasets (DAVIS, DAVSOD, VideoSD, Segtrack‐v2) show the effectiveness of the proposed method. In particular, the state‐of‐the‐art methods on completely unfamiliar datasets (no fine‐tuned datasets) are performed.
Object tracking using temporally matching filters
Authors: Robeson Brendan , Javanmardi Mohammadreza , Qi Xiaojun
Published: March 2021

One of the primary challenges of visual tracking is the variable appearance of the target object. As tracking proceeds, the target object can change its appearance due to illumination changes, rotations, deformations etc. Modern trackers incorporate online updating to learn how the target changes over time. However, they do not use the history of target appearance. To address this shortcoming, we uniquely use domain adaptation with the target appearance history to efficiently learn a temporally matching filter (TMF) during online updating. This TMF emphasizes the persistent features found in different appearances of the target object. It also improves the classification accuracy of the convolutional neural network by assisting the training of the classification layers without incurring the runtime overhead of updating the convolutional layers. Extensive experimental results demonstrate that the proposed TMF‐based tracker, which incorporates domain adaptation with the target appearance history, improves tracking performance on three benchmark video databases (OTB‐50, OTB‐100 and VOT2016) over other online learning trackers. Specifically, it improves the overlap success of VITAL and MDNet by 0.44 % and 1.03 % on the OTB‐100 dataset and improves the accuracy of VITAL and MDNet by 0.55 % and 0.06 % on the VOT2016 dataset, respectively.
Point cloud super‐resolution based on geometric constraints
Authors: Li Xiaoqiang , Liu Jitao , Dai Songmin
Published: March 2021

Among all digital representations we have for real physical objects, three‐dimensional (3D) is arguably the most expressive encoding. But due to the limitations of 3D scanning equipment, point cloud often becomes sparse or partially missing. A point cloud super‐resolution (PCSR) method based on geometric constraints is proposed to solve the sparse problem of point clouds: it allows dense point clouds to be generated by sparse point clouds. The method is based on the conditional generative adversarial network including redesigned generator and discriminator for point cloud data specially. Moreover, the method can maintain the shape of the dense point cloud by adding geometric constraints. The contributions of our work are as follows: (1) a PCSR method based on geometric constraints is proposed; (2) add a module for obtaining point cloud neighbourhood information in the generator, called K‐nn operation module; and (3) feature aggregation is performed using the weighted pooling to process the neighbourhood information obtained by the K‐nn operation module. Extensive experimental results demonstrate the effectiveness of the proposed method.
A novel partial discharge localization method for GIL based on the 3D optical signal irradiance fingerprint and bagging‐KELM
Authors: Zang Yiming , Qian Yong , Zhou Xiaoli , Xu Antian , Sheng Gehao , Jiang Xiuchen
Published: March 2021

Partial discharge (PD) is one of the main reasons that endanger the safe operation of power equipment. The effective detection and localization of PD in a gas‐insulated transmission line (GIL) is essential for timely finding the insulation defects to improve maintenance efficiency. Therefore, this paper proposes a method based on the three‐dimensional optical signal irradiance fingerprint and bagging‐kernel extreme learning machine (Bagging‐KELM), which introduces optical simulation into the PD localization. Using a simulation model with the same size and optical sensor arrangement as the experimental GIL, optical simulation signals emitted from different PD sources are collected. Principal component analysis is used to extract the signal features to construct optical PD fingerprints that correspond to PD source locations. This paper builds all the simulated PD fingerprints into a PD fingerprint database. Afterwards, the Bagging‐KELM is used to match PD optical fingerprints detected on site with the fingerprint database to identify the location of the PD sources. The experimental results show that the average localization error of this method is 0.93 cm, with 93.75% of the errors being less than 1.5 cm. The proposed method has better performance than the traditional KELM and BPNN, which can achieve precise PD localization in GIL.
A weighted graph‐based method for detection of data integrity attacks in electricity markets
Authors: Moslemi Ramin , Mesbahi Afshin , Mohammadpour Velni Javad
Published: March 2021

The negative impacts of data integrity attacks against multi‐settlement electricity markets have been recently studied. It has been shown that adversaries could launch profitable cyber attacks by casting an incorrect image of transmission lines' congestion pattern while simultaneously submitting bogus bids in electricity markets. Although a variety of countermeasures have been proposed in the literature to detect such data integrity attacks, none of those approaches has been designed specifically to ensure data integrity of multi‐settlement electricity markets. The existing methods may even fail to detect complicated types of attacks (e.g. unobservable false data injection attacks) or fail to address practical constraints and requirements of the electricity markets. As an example, most of the attack detection approaches have been established based on the DC economic dispatch, while the modern electricity markets may use AC models. This paper proposes a new anomaly detection tool based on graph theory using so‐called egonets, specifically designed to detect false data injection attacks against electricity markets. In contrast with the conventional detection methods, the malicious intention of the adversaries is exploited in the design procedure. Therefore, the proposed approach can detect false data injection attacks, regardless of the attack type and power flow model.
Newly designed identifying method for ice thickness on high‐voltage transmission lines via machine vision
Authors: Weng Bingjun , Gao Wei , Zheng Weicou , Yang Gengjie
Published: March 2021

The icing of transmission lines will bring considerable challenges to the safe operation of the power grid. Therefore, a novel method combines machine vision and machine learning algorithms for identifying the ice thickness on high‐voltage transmission line (HVTL) as proposed herein. First, noise and background interference in the image are filtered, and the grey image is used as input. Then, the algorithms of improved Canny edge detection, Hough transform, improved K‐means clustering, and least‐squares fitting are adopted in turn to locate the edges of conductors. Finally, according to the distance mapping model based on monocular vision, the ice thickness of the conductor is determined by calculating the width difference before and after icing. The experimental results show that the proposed method can accurately locate the edge of the conductor in both field and experimental environments. Moreover, it can ensure ideal effects under different illumination and hardly not be affected by distortion in both horizontal and vertical directions. Besides, the distance mapping model can map the pixel distance to the actual distance with high precision, no matter whether the background is simple or complex, and the calculated ice thickness has only a small deviation compared to the actual value. In addition, the proposed method shows high reliability and effectiveness when various interference such as different backgrounds, uneven icing, height difference changes, conductor movement, contrast changes, and conductor sag occur.
Modeling and evaluation of a ridesharing matching system from multi‐stakeholders’ perspective
Authors: Rahman Md Tawhidur , Dey Kakan , Martinelli David R. , Mishra Sabya
Published: March 2021

Matching riders and drivers in ridesharing considering conflicting objectives of diverse stakeholders is challenging. The objective of this research is to formulate and evaluate the performance of four ridesharing matching‐objectives (i.e. system‐wide minimisation of passengers’ wait time, minimisation of VMT, minimisation of detour distance, maximisation of drivers’ profit) considering interests of diverse mobility stakeholders (i.e. drivers, riders, matching agencies, government transportation agencies). A grid roadway network was used to compare the performance of the four matching‐objectives in serving a ridesharing demand scenario. Performance comparison of matching‐objectives revealed that a system‐wide VMT minimisation matching‐objective performed best with least sacrifices on the other three matching‐objectives from their respective best performance level. Also, system‐wide VMT minimisation was the best matching‐objective, when drivers’ and government transportation agencies’ expectations were prioritised. System‐wide drivers’ profit maximisation matching‐objective provided the highest monetary incentives for drivers and riders in terms of maximising profit and travel cost savings, respectively. System‐wide minimisation of detour distance was found to be least flexible in providing shared rides. The findings of this research provide useful insights on ridesharing matching system modelling and performance evaluation based on different matching‐objectives and can be used in developing and implementing ridesharing service considering multiple stakeholders’ concerns.
Asymptotic solution for the electromagnetic scattering of a vertical dipole over plasmonic and non‐plasmonic half‐spaces
Authors: Nazari Mohsen Eslami , Huang Weimin
Published: March 2021

A new asymptotic solution for the scattered electromagnetic fields of a vertical Hertzian dipole antenna in the presence of an imperfectly conducting half‐plane for ordinary and plasmonic media is proposed. The scattered electric and magnetic field components are calculated from the intermediate Hertz potential expressed in terms of the Fourier‐Bessel transforms associated with the Sommerfeld‐type integral, which is difficult to evaluate due to the singularities of the integrand near the integration path and its oscillatory and slowly decaying integrand. Using the modified saddle point method, an approximate closed‐form solution of the far‐zone scattered electromagnetic fields including surface waves is presented. The new formulations are applied to calculate radiation patterns of different impedance half‐planes for both ordinary and plasmonic media, that is, seawater, silty clay soil, silty loam soil and lake water as ordinary, and silver and gold as plasmonic media. Furthermore, a numerical evaluation of the proposed solution at various frequencies and comparisons with two alternative state of the art solutions shows that the proposed solution has higher accuracy in terms of the normalised root‐mean‐square error and the normalised maximum absolute error for plasmonic and non‐plasmonic structures.
Wideband IMD3 suppression through negative baseband impedance synthesis
Authors: Sear William , Barton Taylor W.
Published: March 2021

This article presents a power amplifier (PA) linearisation approach based on synthesising a negative impedance termination at the baseband frequency. Negative baseband termination has been previously shown to suppress intermodulation distortion (IMD) products in power amplifiers. Here, this effect is synthesised using a passive feedback network between the drain and gate bias paths of the PA, so that the IMD is suppressed without an increase in the system complexity. The design targets IMD3 suppression at the PA's 3‐dB compression point (P3dB), enabling linear operation into compression, therefore, resulting in improved device utilisation and efficiency. Based on simulation of the feedback response over a 1‐200 MHz frequency range, a network topology is designed that provides both the bias structure and the appropriate transfer function for IMD3 suppression, demonstrating the first reported practical structure to realize this behaviour over a wide range of baseband frequencies. Two different transfer functions are implemented and compared in performance to the nominal design case with standard baseband terminations. Due to the feedback nature of the approach, stability is also addressed. The 2.14‐GHz proof‐of‐concept prototype with feedback exhibits up to 9.5 dB suppression of the two‐tone IMD3 over 10‐150 MHz tone spacing, without reducing the CW performance of the PA.
Novel 4‐bit second‐order multifunction frequency selective surface
Authors: Shah Gulab , Cao Qunsheng , Azeem Muhammad , Ul Abidin Zain
Published: March 2021

An innovative four‐bit second order multifunction active frequency selective structure controlled via four PIN diodes with nine different combinations is introduced . The proposed design is equipped with electromagnetic switching, frequency switching and polarization selection at two passbands. The coding states 0000 and 1111 offer transmission to the passbands centred at 1.96 and 4.98 GHz frequencies and shield to the bands centred at 4.98 and 1.96 GHz for transverse electric (TE)/transverse magnetic (TM) waves, respectively. The coding state 1010 offers transmission to the TE and TM waves at 1.96 GHz and 4.98 GHz, respectively and shields the TM and TE waves at 1.96 GHz and 4.98 GHz, respectively. Contrarily, the coding state 0101 offers transmission to the TE and TM waves at 4.98 GHz and 1.96 GHz, respectively and shields the TE and TM waves at 1.96 GHz and 4.98 GHz, respectively. The coding states 1000/0100 and 1101/1110 allow transmission to the TE wave at 1.96 and 4.98 GHz frequencies, respectively and shield to both the passbands at TM wave. Conversely, the coding states 0001/0100 and 1011/0111 allow transmission to the TM wave at 1.96 and 4.98 GHz frequencies, respectively and shields to both the passbands at TE wave. The coding state 1100/0011 provides shield to all the frequencies below 7.7 GHz. The designed structure is validated through the measured response of the fabricated prototype.
Miniaturized and enhanced bandwidth Marchand balun using CSRR
Authors: Deb Partha Kumar , Moyra Tamasi , Bhattacharyya Bidyut Kumar
Published: March 2021

A novel and miniaturized Marchand balun is proposed using two quarter‐wave edge coupled transmission line and two complementary split‐ring resonators (CSRR) unit cell in the ground plane. These coupled lines are joined with the help of an uncoupled microstrip line. The short circuit and open circuit terminations are assigned at the specified ports. Two rectangular shaped CSRR cells improve the circuit performance. A step impedance technique has been applied at the balanced ports to enhance the bandwidth. This proposed design produces a fractional bandwidth of 18.75% at the centre frequency with a maximum magnitude and phase imbalance of 0.56 dB and 0.85°. This design occupies a total circuit area of 0.515 λg (30.72 mm) × 0.279λg (16.63 mm). The circuit has been designed at 2.4 GHz centre frequency using low‐cost FR4 substrate material. The simulated and measured results are in acceptable accord in terms of magnitude and phase response.
AlGaAs/GaAs asymmetric‐waveguide, short cavity laser diode design with a bulk active layer near the p‐cladding for high pulsed power emission
Authors: Avrutin Eugene A. , Ryvkin Boris S. , Kostamovaara Juha T.
Published: March 2021

It is shown theoretically that a GaAs/AlGaAs laser diode design using an asymmetric waveguide structure and a bulk active layer (AL), located close to the p‐cladding, can provide high output power in a single, broad transverse mode for short‐wavelength (<0.9 μm, matching the spectral range of high efficiency of silicon photodetectors) pulsed emission in the nanosecond pulse duration region, typically <<100 ns. The dependences of the laser performance on the thickness of the AL and the cavity length are analysed. It is shown that the relatively thick bulk AL allows the of short cavity lengths (<1 mm), for achieving high pulsed power while maintaining a relatively low series resistance and a narrow far field.
High amplitude sensitivity gold‐coated trichannel photonic crystal fibre for refractive index sensor
Authors: Dhinakaran Vijayalakshmi , Chellappan Thangappan Manimegalai , Natesan Ayyanar , Krishnan Kalimuthu
Published: March 2021

We propose highly sensitive trichannel photonic crystal fibre (TCPCF) refractive index (RI) sensor based surface plasmon resonance (SPR). In this design, we have been integrated the sensing layer with thin gold metal deposited over the surface of the TCPCF for fabrication feasible and easy liquid infiltration. Then, Y‐shaped channel is formed through reducing the diametre of air holes for controlling the direction of light through photonic crystal fibre to attain high sensitivity. Also, effective coupling between surface plasmon polariton mode at the metal layer and the core‐guided mode is obtained by numerical simulation of finite element method. The optimized TCPCF sensor exhibits maximum amplitude sensitivity of 1938.5 RIU−1 and wavelength sensitivity of 11,000 nm.RIU−1 within the analyte range from 1.34 to 1.39. Further, we have achieved amplitude resolution of 5.2 × 10−6 RIU and wavelength resolution of 9.1 × 10−6 RIU. It is confirmed high detection accuracy for small changes in RI analyte. Moreover, high figure of merit of 623.9 RIU−1 is obtained for the proposed sensor. Therefore, the proposed TCPCF RI sensor can be utilized in the chemical, bio and gas sensing applications.
Circuit centric quantum architecture design
Authors: Azad Utkarsh , Papneja Ankit , Saini Rakesh , Behera Bikash K. , Panigrahi Prasanta K.
Published: March 2021

With the development in the field of quantum physics, several methods for building a quantum computer have emerged. These differ in qubit technologies, interaction topologies, and noise characteristics. In this article, insights are given into the circuit‐centric architecture design of Noisy Intermediate‐Scale Quantum (NISQ) devices. The dependence of the circuit size, circuit depth on the interaction and connection between different qubits present in quantum hardware are discussed. A noise‐aware procedure is presented which helps in determining the optimal interactions between different qubits of a quantum chip to execute a given circuit in the most efficient way possible. In this article, the 5‐qubit hardware in a noiseless setting is illustrated with an example. Also, a benchmark‐driven analysis is performed to show the importance of noise adaptivity in determining the hardware reliability. It is concluded that a generalized and flexible procedure such as this approach can aid in determining the design of hardware accurately for which the circuit runs efficiently, that is, with the least number of clock cycles, the lowest gate operations, and noise‐based errors.
Classification of human activity using radar and video multimodal learning
Authors: de Jong Richard J. , de Wit Jacco J.M. , Uysal Faruk
Published: March 2021

In the defence and security domain, camera systems are widely used for surveillance. The major advantage of using camera systems for surveillance is that they provide high‐resolution imagery, which is easy to interpret. However, the use of camera systems and optical imagery has some drawbacks, especially for application in the military domain. In poor lighting conditions, dust or smoke the image quality degrades and, additionally, cameras cannot provide range information too. These drawbacks can be mitigated by exploiting the strengths of radar. Radar performance can be largely maintained during the night, in various weather conditions and in dust and smoke. Moreover, radar provides the distance to detected objects. Since, the strongpoints and weaknesses of radar and camera systems seem complementary, a natural question is: can radar and camera systems learn from each other? Here the potential of radar/video multimodal learning is evaluated for human activity classification. The novelty of this work is the use of radar spectrograms and related video frames for classification with a multimodal neural network. Radar spectrograms and video frames are both two‐dimensional images, but the information they contain is of different nature. This approach was adopted to limit the required preprocessing load, while maintaining the complementary nature of the sensor data.
State Feedback and Synergetic controllers for tuberculosis in infected population
Authors: Bilal Muhammad , Ahmad Iftikhar , Babar Sheraz Ahmad , Shahzad Khurram
Published: March 2021

Tuberculosis (TB) is a contagious disease which can easily be disseminated in a society. A five state Susceptible, exposed, infected, recovered and resistant (SEIRs) epidemiological mathematical model of TB has been considered along with two non‐linear controllers: State Feedback (SFB) and Synergetic controllers have been designed for the control and prevention of the TB in a population. Using the proposed controllers, the infected individuals have been reduced/controlled via treatment, and susceptible individuals have been prevented from the disease via vaccination. A mathematical analysis has been carried out to prove the asymptotic stability of proposed controllers by invoking the Lyapunov control theory. Simulation results using MATLAB/Simulink manifest that the non‐linear controllers show fast convergence of the system states to their respective desired levels. Comparison shows that proposed SFB controller performs better than Synergetic controller in terms of convergence time, steady state error and oscillations.
Bright betatron x-rays generation from picosecond laser interactions with long-scale near critical density plasmas
Authors: Shen X. F. , Pukhov A. , Günther M. M. , Rosmej O. N.
Published: March 2021

Our previous experimental and three-dimensional (3D) particle-in-cell (PIC) simulation results demonstrated that a well-directed electron beam with space charge of about μC and maximum energy of 100 MeV can be generated via a sub-petawatt, picosecond laser pulse interacting with a long-scale near-critical-density plasma. Effective laser energy coupling into hot electrons occurs in the presence of strong self-generated quasistatic electric and magnetic fields that confine fast electrons in relativistic ion channels. Here, we report results of 3D PIC simulations, which show that this direct laser accelerated electron beam can work as a compact high-brightness source of x rays. The relativistic electrons make betatron oscillations in the transverse fields of the ion channel and emit a bright broadband x-ray radiation with the critical energy of about 5 keV. Due to the huge number of accelerated electrons, our simulation shows that with a picosecond, 20 J laser pulse, an x-ray spectrum with a photon number of 7×1011 (>1 keV) can be generated, resulting into a peak flux of 2 ×108 photons/eV and a brilliance of 3.3×1020 photons/s/mm2/mrad2/0.1%BW.
Fight against COVID-19: The case of antiviral surfaces
Authors: Shirvanimoghaddam Kamyar , Akbari Mohammad Karbalaei , Yadav Ram , Al-Tamimi Adil K. , Naebe Minoo
Published: March 2021

The COVID-19 pandemic is the largest global public health outbreak in the 21st century so far. Based on World Health Organization reports, the main source of SARS-CoV-2 infection is transmission of droplets released when an infected person coughs, sneezes, or exhales. Viral particles can remain in the air and on the surfaces for a long time. These droplets are too heavy to float in air and rapidly fall down onto the surfaces. To minimize the risk of the infection, entire surrounding environment should be disinfected or neutralized regularly. Development of the antiviral coating for the surface of objects that are frequently used by the public could be a practical route to prevent the spread of the viral particles and inactivation of the transmission of the viruses. In this short review, the design of the antiviral coating to combat the spread of different viruses has been discussed and the technological attempts for minimizing the coronavirus outbreak have been highlighted.
The skin-friction coefficient of a turbulent boundary layer modified by a large-eddy break-up device
Authors: Chan I. C. , Örlü R. , Schlatter P. , Chin R. C.
Published: March 2021

A computational study based on well-resolved large-eddy simulations is performed to study the skin friction modification by a large-eddy breakup device (LEBU) in a zero-pressure-gradient turbulent boundary layer. The LEBU was modeled using an immersed boundary method. It is observed that the presence of the device leads to the generation of wake vortices, which propagate downstream from the LEBU and toward the wall. A skin friction decomposition procedure is utilized to study different physical mechanisms of the observed skin friction reduction. From the skin friction decomposition, it is found that the skin friction reduction can be characterized by three universal regions of different changes for the skin friction contributions. The first region is predominantly associated with the formation of the wake vortices and the reduction of Reynolds shear stress. In the second region, the mean streamwise velocity fields show that a region of velocity deficit formed downstream of the LEBU propagates toward the wall and leads to turbulence reduction due to wake wall interactions, which also induces a local maximum skin friction reduction. In the third region, the dissipation of wake vortices leads to the regeneration of Reynolds shear stress. A quadrant analysis of the Reynolds shear stress contribution reveals that the LEBU increases the Q2 and Q4 contributions and attenuates the Q1 and Q3 contributions in the first region, followed by an onset of Reynolds shear stress further downstream.
Disorder effect of 3d transition elements in DO3 Heusler alloy Mn2FeAl
Authors: Lv Bing , Liu Pei , Miao Yu , Lian Zhongyuan , Si Mingsu , Gao Cunxu
Published: March 2021

DO3 disorder is essential to elucidate the properties of many 3d group Heusler alloys, especially Mn2-based alloys. The DO3 disorder for Mn2FeAl, corresponding to the exchange between Mn and Fe atoms, is difficult to distinguish with the normal x-ray diffraction instrument because of similar atomic scattering factors for Mn and Fe atoms. However, via the observation of magnetic behavior, the DO3 disorder has been observed indirectly. Many pieces of evidence show the existence of DO3 disorder in our samples. A qualitative method is employed to clarify the degree of DO3 disorder for Mn2FeAl alloys with the results of first-principles calculations, and this method can be applied to many Mn2-based alloys. In addition, full ordering occupation of Al atoms has been observed and Mn2FeAl without any disorder could be prepared hopefully for further work.
Were warriors once low carb? Commentary on New Zealand Māori nutrition and anthropometrics over the last 150 years
Authors: Hawkins Marcus
Published: March 2021

ABSTRACT Obesity is a scourge on modern society and an epidemic has exploded in the developed world over the last half century, resulting in sicker populations and economically unsustainable health expenditure. The Pacific region became colonised by Europeans from the early nineteenth century onwards and, as a consequence, ‘European’ foodstuffs were introduced to New Zealand Māori. This has intensified over the last 150 years; so much so, that obesity is now common among New Zealand Māori, who suffer disproportionately from the chronic diseases arising from obesity. This commentary seeks to explore and compare the ‘then’ and ‘now’ in terms of New Zealand Māori nutrition and anthropometrics. It also asks the specific questions: were New Zealand Māori originally eating a low carbohydrate healthy fat diet? and should we all now reflect on a previous dietary pattern of eating in an effort to reverse the obesity epidemic?