bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leaching and solvent extraction purification of zinc from Mehdiabad complex oxide ore
Authors: Soltani Faraz , Darabi Hossna , Aram Reza , Ghadiri Mahdi 
Published: January 2021

AbstractAn integrated hydrometallurgical process was used for the zinc leaching and purification from a zinc ore containing 9.75 wt% zinc. The zinc minerals in the ore were hemimorphite, willemite, and calcophanite. Main gangue minerals were quartz, goethite, hematite, and calcite. Central composite design (CCD) method was used to design leaching experiments and the optimum conditions were found as follows: 30% of solid fraction, 22.05% sulphuric acid concentration, and the leaching temperature of 45 °C. The PLS containing 35.07 g/L zinc, 3.16 g/L iron, and 4.58 g/L manganese impurities was produced. A special purification process including Fe precipitation and Zn solvent extraction was implemented. The results showed that after precipitation of iron, Zn extraction of 88.5% was obtained with the 2 stages extraction system composed of 30 vol% D2EHPA as extractant. The overall Zn recovery from the ore was 71.44%. Therefore, an appropriate solution containing 16.6 g/L Zn, 0.05 g/L Fe, and 0.11 g/L Mn was prepared for the electro-winning unit without using the roasting and calcination steps (conventional method), which result in environmental pollution.
Metabolomics-based analysis of miniature flask contents identifies tobacco mixture use among the ancient Maya
Authors: Zimmermann Mario , Brownstein Korey J. , Pantoja Díaz Luis , Ancona Aragón Iliana , Hutson Scott , Kidder Barry , Tushingham Shannon , Gang David R. 
Published: January 2021

AbstractA particular type of miniature ceramic vessel locally known as “veneneras” is occasionally found during archaeological excavations in the Maya Area. To date, only one study of a collection of such containers successfully identified organic residues through coupled chromatography–mass spectrometry methods. That study identified traces of nicotine likely associated with tobacco. Here we present a more complete picture by analyzing a suite of possible complementary ingredients in tobacco mixtures across a collection of 14 miniature vessels. The collection includes four different vessel forms and allows for the comparison of specimens which had previously formed part of museum exhibitions with recently excavated, untreated containers. Archaeological samples were compared with fresh as well as cured reference materials from two different species of tobacco (Nicotiana tabacum and N. rustica). In addition, we sampled six more plants which are linked to mind-altering practices through Mesoamerican ethnohistoric or ethnographic records. Analyses were conducted using UPLC-MS metabolomics-based analytical techniques, which significantly expand the possible detection of chemical compounds compared to previous biomarker-focused studies. Results include the detection of more than 9000 residual chemical features. We trace, for the first time, the presence of Mexican marigold (Tagetes lucida) in presumptive polydrug mixtures.
Regional abnormality of functional connectivity is associated with clinical manifestations in individuals with intractable focal epilepsy
Authors: Nakai Yasuo , Nishibayashi Hiroki , Donishi Tomohiro , Terada Masaki , Nakao Naoyuki , Kaneoke Yoshiki 
Published: January 2021

AbstractWe explored regional functional connectivity alterations in intractable focal epilepsy brains using resting-state functional MRI. Distributions of the network parameters (corresponding to degree and eigenvector centrality) measured at each brain region for all 25 patients were significantly different from age- and sex-matched control data that were estimated by a healthy control dataset (n = 582, 18–84 years old). The number of abnormal regions whose parameters exceeded the mean + 2 SD of age- and sex-matched data for each patient were associated with various clinical parameters such as the duration of illness and seizure severity. Furthermore, abnormal regions for each patient tended to have functional connections with each other (mean ± SD = 58.6 ± 20.2%), the magnitude of which was negatively related to the quality of life. The abnormal regions distributed within the default mode network with significantly higher probability (p < 0.05) in 7 of 25 patients. We consider that the detection of abnormal regions by functional connectivity analysis using a large number of control datasets is useful for the numerical assessment of each patient’s clinical conditions, although further study is necessary to elucidate etiology-specific abnormalities.
Microfluidic on-chip production of microgels using combined geometries
Authors: Shieh Hamed , Saadatmand Maryam , Eskandari Mahnaz , Bastani Dariush 
Published: January 2021

AbstractMicrofluidic on-chip production of microgels using external gelation can serve numerous applications that involve encapsulation of sensitive cargos. Nevertheless, on-chip production of microgels in microfluidic devices can be challenging due to problems induced by the rapid increase in precursor solution viscosity like clogging. Here, a novel design incorporating a step, which includes a sudden increase in cross-sectional area, before a flow-focusing nozzle was proposed for microfluidic droplet generators. Besides, a shielding oil phase was utilized to avoid the occurrence of emulsification and gelation stages simultaneously. The step which was located before the flow-focusing nozzle facilitated the full shielding of the dispersed phase due to 3-dimensional fluid flow in this geometry. The results showed that the microfluidic device was capable of generating highly monodispersed spherical droplets (CV < 2% for step and CV < 5% for flow-focusing nozzle) with an average diameter in the range of 90–190 μm, both in step and flow-focusing nozzle. Moreover, it was proved that the device could adequately create a shelter for the dispersed phase regardless of the droplet formation locus. The ability of this microfluidic device in the production of microgels was validated by creating alginate microgels (with an average diameter of ~ 100 μm) through an external gelation process with on-chip calcium chloride emulsion in mineral oil.
Quantitative estimation of track segment yields of water radiolysis species under heavy ions around Bragg peak energies using Geant4-DNA
Authors: Baba Kentaro , Kusumoto Tamon , Okada Shogo , Ogawara Ryo , Kodaira Satoshi , Raffy Quentin , Barillon Rémi , Ludwig Nicolas , Galindo Catherine , Peaupardin Philippe , Ishikawa Masayori 
Published: January 2021

AbstractWe evaluate the track segment yield G′ of typical water radiolysis products (eaq−, ·OH and H2O2) under heavy ions (He, C and Fe ions) using a Monte Carlo simulation code in the Geant4-DNA. Furthermore, we reproduce experimental results of ·OH of He and C ions around the Bragg peak energies (< 6 MeV/u). In the relatively high energy region (e.g., > 10 MeV/u), the simulation results using Geant4-DNA have agreed with experimental results. However, the G-values of water radiolysis species have not been properly evaluated around the Bragg peak energies, at which high ionizing density can be expected. Around the Bragg peak energy, dense continuous secondary products are generated, so that it is necessary to simulate the radical–radical reaction more accurately. To do so, we added the role of secondary products formed by irradiation. Consequently, our simulation results are in good agreement with experimental results and previous simulations not only in the high-energy region but also around the Bragg peak. Several future issues are also discussed regarding the roles of fragmentation and multi-ionization to realize more realistic simulations.
Interfacial reaction during friction stir assisted scribe welding of immiscible Fe and Mg alloy system
Authors: Das Hrishikesh , Upadhyay Piyush , Wang Tianhao , Gwalani Bharat , Ma Xiaolong 
Published: January 2021

AbstractWe report on interfacial characteristics and chemistry of bonded Mg-Fe interfaces welded using friction stir assisted scribe technique (FaST). Two pairs of dissimilar joints: (AZ31-DP590) and (Pure Mg-DP590) were studied to shed light on joining mechanisms responsible for bonding of “immiscible” pairs of Mg and Fe. We present first direct experimental evidence of presence of oxide layer, Al segregation by atom probe tomography and nano steel grains close to interface by transmission electron microscopy study.
Chronic musculoskeletal pain prospectively predicts insomnia in older people, not moderated by age, gender or co-morbid illnesses
Authors: Sit Regina Wing Shan , Yip Benjamin Hon Kei , Wang Bo , Chan Dicken Cheong Chun , Zhang Dexing , Wong Samuel Yeung Shan 
Published: January 2021

AbstractThe study evaluated if chronic musculoskeletal (MSK) pain predicts the severity of insomnia, and whether the effect is moderated by age, gender, and number of comorbid diseases in older people. An 18-month prospective study was performed within the framework of a community health program in Hong Kong. A total of 498 older people aged ≥ 60 with multimorbidity were recruited. The predictors included the presence of chronic MSK pain, pain measured by the Brief Pain Inventory (BPI), insomnia measured by baseline Insomnia Severity Index (ISI), and number of co-morbid diseases, age, and gender. The outcome was ISI repeated at 18 months. The moderators included age, gender, and number of comorbid diseases. Multivariate linear regression and moderation analysis were conducted. We found that the presence of chronic MSK pain (β = 1.725; 95% CI, 0.607–2.842; P < 0.01) predicted the severity of ISI, after controlling for age, gender, BMI, and the number of comorbid diseases. Participants with chronic MSK pain throughout the period had worse trend of improvement in ISI compared to those who were “pain-free” (β = 2.597; 95% CI, 1.311–3.882; P < 0.001). Age, gender, and number of comorbid diseases did not moderate the longitudinal relationship. We propose that pain management should prioritized in the prevention of insomnia.
PAPR analysis of non‐contiguous duplex multicarrier signals
Authors: Savaux V. , Louët Y. 
Published: January 2021

AbstractThis paper deals with the peak to average power ratio of duplex multicarrier signals. A simple but accurate expression of the complementary cumulative distribution of the peak to average power ratio is suggested, based on both empirical and theoretical analyses of the mean peak to average power ratio of such a continuous duplex signal. To this end, it is shown that the mean peak to average power ratio can be written in function of the frequency distance between the two signals composing the duplex one. The relevance and the accuracy of the suggested analysis are shown through simulations, and a discussion paves the way to further analyses involving general multiplex signals with different powers and subcarriers numbers.
Super‐high‐frequency‐band injection‐locked two‐divider oscillator using thin‐film bulk acoustic resonator
Authors: Hara Motoaki , Yano Yuichiro , Takahashi Yuki , Nishizawa Toshio , Hara Shinsuke , Kasamatsu Akifumi , Ueda Masanori , Ito Hiroyuki , Ido Tetsuya 
Published: January 2021

AbstractAn injection‐locked divider oscillator that converts a 6‐GHz‐band signal into a 3‐GHz‐band signal was developed. The injection‐locked divider oscillator was specifically designed to lock on the clock transition frequency of 87Rb of 6.824 GHz to provide a laser modulation signal at 3.417 GHz for an on‐chip coherent population trapping atomic clock system. To obtain high frequency stability and low‐phase noise with low power consumption in the super‐high‐frequency band, a thin‐film bulk acoustic resonator is used instead of the conventional LC tank circuit. The fabricated oscillator operated well with a power consumption of 4.5 nW. The maximum lock range was 1.5% in fractional frequency. Also, unlike the conventional injection‐locked divider oscillator with an LC tank, the bifurcation of the lock range width was observed when sweeping the injection power of the 6‐GHz‐band signal, and in the down sweep, the locking operation was maintained even at an injection power of −20 dBm.
A new technique for separation of partial discharge sources and electromagnetic noise in radiofrequency measurements using energy ratios of different antennas
Authors: Ardila‐Rey Jorge A. , Cerda‐Luna Matias , Rozas‐Valderrama Rodrigo , Albuquerque de Castro Bruno , Andreoli André Luiz , Cevallos Benjamin 
Published: January 2021

AbstractOne of the main tools for monitoring the condition of high voltage equipment is the measurement of partial discharges (PD). The electromagnetic (EM) radiation originated from this degradation phenomenon can be captured by various types of ultra‐high frequency (UHF) antennas carefully designed and optimised for specific frequency bands. However, the presence of environmental noise may limit the use of this technique. Different types of monopole antennas normally used in UHF PD measurement have been evaluated in order to validate the performance of a novel separation technique of EM sources. Accordingly, a new separation technique based on the energy ratio of the captured signals was developed, considering noise interferences. The results revealed that the new technique allows an adequate separation, even when three sources act simultaneously.
Recurrent learning with clique structures for prostate sparse‐view CT artifacts reduction
Authors: Shen Tiancheng , Yang Yibo , Lin Zhouchen , Zhang Mingbin 
Published: January 2021

AbstractIn recent years, convolutional neural networks have achieved great success in streak artifacts reduction. However, there is no special method designed for the artifacts reduction of the prostate. To solve the problem, the artifacts reduction CliqueNet (ARCliqueNet) to reconstruct dense‐view computed tomography images form sparse‐view computed tomography images is proposed. In detail, first, the proposed ARCliqueNet extracts a set of feature maps from the prostate sparse‐view CT image by Clique Block. Second, the feature maps are sent to ASPP with memory to be refined. Thenanother Clique Block is applied to the output of ASPP with memory and reconstruct the dense‐view CT images. Later on, reconstructed dense‐view CT images are used as new input of the original network. This process is repeated recurrently with memory delivering information between these recurrent stages. The final reconstructed dense‐view CT images are the output of the last recurrent stage. Our proposed ARCliqueNet outperforms the SOTA (state‐of‐the‐art) general artifacts reduction methods on the prostate dataset in terms of PSNR (peak signal‐to‐noise ratio) and SSIM (structural similarity). Therefore, we can draw the conclusion that Clique structures, ASPP with memory and recurrent learning are useful for prostate sparse‐view CT Artifacts here.
Crowd counting with segmentation attention convolutional neural network
Authors: Chen Jiwei , Wang Zengfu 
Published: January 2021

AbstractDeep learning occupies an undisputed dominance in crowd counting. This paper proposes a novel convolutional neural network architecture called SegCrowdNet. Despite the complex background in crowd scenes, the proposed SegCrowdNet still adaptively highlights the human head region and suppresses the non‐head region by segmentation. With the guidance of an attention mechanism, the proposed SegCrowdNet pays more attention to the human head region and automatically encodes the highly refined density map. The crowd count can be obtained by integrating the density map. To adapt the variation of crowd counts, SegCrowdNet intelligently classifies the crowd count of each image into several groups. In addition, the multi‐scale features are learned and extracted in the proposed SegCrowdNet to overcome the scale variations of the crowd. To verify the effectiveness of this proposed method, extensive experiments are conducted on four challenging datasets. The results demonstrate that the proposed SegCrowdNet achieves excellent performance compared with the state‐of‐the‐art methods.
An SDN empowered location aware routing for energy efficient next generation vehicular networks
Authors: Renuka Kumari , Roy Diptendu Sinha , Reddy K. Hemant Kumar 
Published: January 2021

AbstractWith the ever expanding and all pervasive growth of information and communication technologies, vehicular ad‐hoc networks (VANETs) have been found wanting for sophistication. The fifth generation (5G) communication has brought about uncharted bandwidth capabilities SDN have enabled real time network control while cloud and fog computing have brought unprecedented computation and storage capabilities for leveraging analytics on massive data volumes and bringing down response times. These information and communication technologies can effectively handle the challenges of next generation autonomous vehicular networks including maintaining road disciplines and safety in VANETs. Moreover, energy efficient operations is the key for any upcoming technology. To this end, this paper assumes the use of 5G and fog computing based vehicular network and using SDN controller's cognizance of global vehicular topology, it proposes an SDN enabled location‐aware routing that intelligently manages workload at fog nodes for reduced energy consumption while satisfying bandwidth and delay constraints. The VANET energy minimization has been formulated as an integer linear programming problem and simulations has been carried out to test the efficacy of the proposed model and the results shows the efficacy of the proposed model 15.74% of improvement of energy consumption as compared that of the optimal algorithm.
Reduction‐controlled graphene oxide saturable absorbers and its effect on ultrashort Er‐doped fibre laser
Authors: Ismail Mohd Afiq , Abdul Razak Mohd Zulhakimi , Harun Sulaiman Wadi , Hashim Abdul Manaf 
Published: January 2021

AbstractThe authors controlled the reduction of three graphene oxide (GO) saturable absorber (SA) thin films by controlling the exposure time under a solar simulator and afterwards, incorporated them into an Er‐doped fibre laser in order to investigate their effect on ultrashort pulse. The authors also hypothesized that the controlled reduction would result in a controlled absorption, and ultimately, a controlled modulation depth. A larger modulation depth would lead to stronger pulse shaping and shorter pulse duration. Sample A was left unreduced, whereas samples B and C were exposed for 15 and 30 min, respectively. Afterwards, their modulation depths were measured using twin‐detector method and determined to be 0.69%, 1.2% and 1.94%, respectively. When used as an SA in an Er‐doped fibre laser, the result showed pulse duration shortening; from 670 to 520 fs, as well as spectral broadening; from 4.22 to 6.73 nm. In addition, we also observed changes in repetition rate, output power and time‐bandwidth product (TBP). The result of this paper shows the feasibility of controlling the modulation depth of a GO SA and conclusively shows the effect of modulation depth on ultrashort pulse.
Generalised predictive current‐mode control of passive front‐end boost‐type converters
Authors: Judewicz M. G. , González S. A. , Fischer J. R. , Martínez J. F. , Carrica D. O. 
Published: January 2021

AbstractIn this work, an average current‐mode control strategy based on a generalised predictive control formulation for passive front‐end three‐phase boost‐type converters is proposed. A novel design procedure for the generalised predictive control strategy is introduced which considers both the cost function and disturbance model as design parameters to set the controller's dynamic response and robustness against component variations. A maximum robustness criterion was used for achieving stability up to a 70% inductance reduction with maximum possible bandwidth. The proposed strategy was compared against both a PI and a predictive deadbeat average current‐mode control using both simulations and experimental results on a converter. The generalised predictive control presented less performance variations between different operating points than the PI controller. Also, the proposed strategy is more robust than the predictive deadbeat strategy, showing a better transient response with a 50% inductance reduction and remained stable for a 71% inductance reduction, while the predictive deadbeat could not. Finally, the proposed strategy achieved a 1.4% output voltage load transient response for a load power step, and a 2.8% output voltage line transient response for a input voltage step, outperforming existing state‐of‐the‐art strategies.
Optimal and automated decentralised converter control design in more electrical aircraft power electronics embedded grids
Authors: Dewar D. , Formentini A. , Li K. , Zanchetta P. , Wheeler P. 
Published: January 2021

AbstractIn modern power systems, the proliferation of power electronics converters, and distributed generation raises important issues concerning inter‐connected switching units in terms of performance, stability and robustness. Such phenomenon are more prominent in micro‐grids, such as modern local low voltage distribution systems, more electric aircraft power systems etc., where many power converters are connected to the same non‐stiff low power ac grid, and strongly interact with each other. Locally designed converter control systems on the same electrical bus exhibit interactive behaviour. If not taken properly into account, external disturbances to the system at given operating conditions may result in the degradation of performance, failure to meet operating conditions and, in some cases, instability. This paper presents a new approach to synthesise converter controllers in more electric aircraft ac distribution grids (which is, however, applicable to all power electronics embedded systems), keeping in consideration dynamic interactions among subsystems. An optimal control design approach based on H2 optimisation is therefore proposed. Phase‐locked loops have also been considered, and their tuning has been included in the general tuning procedure of the whole system. Simulation, and experimental results show good improvements in terms of dynamic performance, and interaction mitigation.
Adaptive backstepping complementary sliding mode control with parameter estimation and dead‐zone modification for PMLSM servo system
Authors: Jin Hongyan , Zhao Ximei , Wang Tianhe 
Published: January 2021

AbstractAn adaptive backstepping complementary sliding mode control (ABCSMC) with dead‐zone parameter modification applicable to the permanent magnet linear synchronous motor is proposed in order to achieve high‐performance servo control fields. On the theoretical foundation of backstepping control and sliding mode control, a strong robust controller, ABCSMC is designed to compensate the uncertainties such as parameter variations and external disturbances occurring in the system. Additionally, an adaptive saturation function is utilized in ABCSMC to avoid the difficulty of parameter selections, so that the optimal parameters can be tuned by the adaptive laws in real time. Moreover, in order to avoid the parameter‐drift phenomenon of the adaptive laws, dead‐zone parameter modification is hereby proposed by setting a performance threshold to solve the overtraining problem. Finally, the stability of the system is proved through Lyapunov theorem and Barbalat's lemma. To investigate the capabilities of the proposed scheme, an experimental platform based on digital signal processor is implemented. The comparison results demonstrate that the proposed controller is capable of achieving higher tracking performance and stronger robustness to uncertainties with respect to parameter variations and external disturbances.