bluuebunny/crossref_metadata_2025 huggingface dataset:
Harnessing the biocatalytic potential of iron- and α-ketoglutarate-dependent dioxygenases in natural product total synthesis
Authors: Zwick Christian R. , Renata Hans
Published: February 2020

This review highlights recent chemoenzymatic syntheses of natural products that feature strategic applications of oxidative transformations with Fe/αKG enzymes.
Interfacial and structural modifications in perovskite solar cells
Authors: Ali Jazib , Li Yu , Gao Peng , Hao Tianyu , Song Jingnan , Zhang Quanzeng , Zhu Lei , Wang Jing , Feng Wei , Hu Hailin , Liu Feng
Published: February 2020

Interface engineering is an efficient strategy for passivating defects, improving carrier dynamics, suppressing ion migration, and enhancing the performance of perovskite photovoltaic cells.
Determination of biocatalytic parameters of a copper radical oxidase using real-time reaction progress monitoring
Authors: Forget Stephanie M. , Xia Fan (Roderick) , Hein Jason E. , Brumer Harry
Published: February 2020

VTNA is applied to reaction progress curves to glean key kinetic and mechanistic details for a copper radical oxidase.
Acoustic interaction between 3D-fabricated cubic bubbles
Authors: Combriat Thomas , Rouby-Poizat Philippine , Doinikov Alexander A. , Stephan Olivier , Marmottant Philippe
Published: February 2020

Spherical bubbles are difficult to hold in specific arrangements and tend to dissolve in water over time. Using 3D-fabricated cubic frames we trap and stabilize bubbles that still oscillate under acoustic excitation.
Single-step fabrication of 3D hierarchical ZnO/ZnS heterojunction branched nanowires by MOCVD for enhanced photoelectrochemical water splitting
Authors: Hassan Mostafa Afifi , Waseem Aadil , Johar Muhammad Ali , Bagal Indrajit V. , Ha Jun-Seok , Ryu Sang-Wan
Published: February 2020

Rational design with a systematic and scalable single-step growth of 3D hierarchical ZnO/ZnS heterojunction branched NWs by MOCVD for enhanced photoelectrochemical water splitting efficiency.
Non-equilibrium organosilane plasma polymerization for modulating the surface of PTFE towards potential blood contact applications
Authors: Vijayan Vineeth M. , Tucker Bernabe S. , Hwang Patrick T. J. , Bobba Pratheek S. , Jun Ho-Wook , Catledge Shane A. , Vohra Yogesh K. , Thomas Vinoy
Published: February 2020

We report a novel and facile organosilane plasma polymerization method designed to improve the surface characteristics of poly(tetrafluoroethylene) (PTFE).
Electrochemiluminescent aptamer-sensor for alpha synuclein oligomer based on a metal–organic framework
Authors: Wu Qian , Tan Rong , Mi Xiaona , Tu Yifeng
Published: February 2020

Two new MOFs based ECL aptasensors showed ultra-sensitivity towards the α-syn oligomer, an important biomarker for Parkinson's disease.
Supramolecular gels derived from nucleoside based bolaamphiphiles as a light-sensitive soft material
Authors: Baillet Julie , Gaubert Alexandra , Bassani Dario M. , Verget Julien , Latxague Laurent , Barthélémy Philippe
Published: February 2020

Light-sensitive Low Molecular Weight Gelators (LMWGs) derived from glyconucleoside bolaamphiphiles containing a stilbene unit displayed gelation abilities in hydroalcoholic mixtures.
Di-lacunary [In6S15]12− cluster: the building block of a highly negatively charged framework for superior Sr2+ adsorption capacities
Authors: Wang Kai-Yao , Sun Meng , Ding Dong , Liu Hua-Wei , Cheng Lin , Wang Cheng
Published: February 2020

Reported is the construction of a highly negatively charged layered material [CH3CH2NH3]6In6S12 (InS-1) by introducing a lacunary cluster as the building block. InS-1 exhibits an effective adsorption for Sr2+ ion with a high qm of 105.35 mg g−1.
A new monooxygenase from Herbaspirillum huttiense catalyzed highly enantioselective epoxidation of allylbenzenes and allylic alcohols
Authors: Lin Hui , Tang Yanhong , Dong Shuang , Lang Ruibo , Chen Hongge
Published: February 2020

An efficient, asymmetric synthesis of allyloxiranes and glycidols with excellent diastereo- and enantioselectivity was established through HhMo-catalyzed epoxidation.
A simple and straightforward strategy for synthesis of N,P co-doped porous carbon: an efficient support for Rh nanoparticles for dehydrogenation of ammonia borane and catalytic application
Authors: Luo Wenxiu , Zhao Xue , Cheng Wei , Zhang Yun , Wang Yi , Fan Guangyin
Published: February 2020

Metal nanoparticles (NPs) deposited on nitrogen (N)- and/or phosphorus (P)-doped porous carbon have been investigated as efficient catalysts for hydrolysis of ammonia borane (AB).
Tolerance factor, phase stability and order–disorder of the pyrochlore structure
Authors: Song Zhen , Liu Quanlin
Published: February 2020

The tolerance factor is a structural indicator used to predict the phase stability of pyrochlore structures from their chemical compositions.
A pH-regulated ratiometric luminescence Eu-MOF for rapid detection of toxic mycotoxin in moldy sugarcane
Authors: Zhao Yifang , Zeng Heng , Wu Kun , Luo Dong , Zhu Xiao-Wei , Lu Weigang , Li Dan
Published: February 2020

pH-Regulated ratiometric luminescence switching from red to blue for rapid detection of 3-nitropropionic acid (3-NPA).
Coptisine, a protoberberine alkaloid, relaxes mouse airway smooth muscle via blockade of VDLCCs and NSCCs
Authors: Wen Nana , Xue Lu , Yang Yongle , Shi Shunbo , Liu Qing-Hua , Cai Congli , Shen Jinhua
Published: February 2020

Background/Aims: Recently, effective and purified ingredients of traditional Chinese medicine (TCM) were extracted to play crucial roles in the treatment of pulmonary diseases. Our previous research focused on TCM drug screening aimed at abnormal airway muscle contraction during respiratory diseases. Coptisine, an effective ingredient extracted from bitter herbs has shown a series of antioxidant, antibacterial, cardioprotective and neuroprotective pharmacological properties. In the current study, we questioned whether coptisine could also participate in asthma treatment through relaxing abnormal contracted mouse airway smooth muscle (ASM). The present study aimed to characterize the relaxant effects of coptisine on mouse ASM and uncover the underlying molecular mechanisms. Methods: To investigate the role of coptisine on pre-contracted mouse ASM, a series of biological techniques, including force measurement and patch-clamp experiments were employed. Results: Coptisine was found to inhibit high K+ or acetylcholine chloride (ACh)-induced pre-contracted mouse tracheal rings in a dose-dependent manner. Further research demonstrated that the coptisine-induced mouse ASM relaxation was mediated by alteration of calcium mobilization via voltage-dependent L-type Ca2+ channels (VDLCCs) and non-selective cation channels (NSCCs). Conclusion: Our data showed that mouse ASM could be relaxed by coptisine via altering the intracellular Ca2+ concentration through blocking VDLCCs and NSCCs, which suggested that this pharmacological active constituent might be classified as a potential new drug for the treatment of abnormal airway muscle contraction.
Whole genome survey analysis and microsatellite motif identification of Sebastiscus marmoratus
Authors: Xu Sheng-yong , Song Na , Xiao Shi-jun , Gao Tian-xiang
Published: February 2020

The marbled rockfish Sebastiscus marmoratus is an ecologically and economically important marine fish species distributed along the northwestern Pacific coast from Japan to the Philippines. Here, next-generation sequencing was used to generate a whole genome survey dataset to provide fundamental information of its genome and develop genome-wide microsatellite markers for S. marmoratus. The genome size of S. marmoratus was estimated as approximate 800 Mb by using K-mer analyses, and its heterozygosity ratio and repeat sequence ratio were 0.17% and 39.65%, respectively. The preliminary assembled genome was nearly 609 Mb with GC content of 41.3%, and the data were used to develop microsatellite markers. A total of 191,592 microsatellite motifs were identified. The most frequent repeat motif was dinucleotide with a frequency of 76.10%, followed by 19.63% trinucleotide, 3.91% tetranucleotide, and 0.36% pentanucleotide motifs. The AC, GAG, and ATAG repeats were the most abundant motifs of dinucleotide, trinucleotide, and tetranucleotide motifs, respectively. In summary, a wide range of candidate microsatellite markers were identified and characterized in the present study using genome survey analysis. High-quality whole genome sequence based on the “Illumina+PacBio+Hi-C” strategy is warranted for further comparative genomics and evolutionary biology studies in this species.
The Training Experiences of Augmentative and Alternative Communication Practitioners in One Midwestern State
Authors: Douglas Sarah N. , West Patricia , Kammes Rebecca
Published: February 2020

Purpose

Services for children with complex communication needs require well-trained practitioners. Yet, research shows that augmentative and alternative communication (AAC) practitioners often receive insufficient preservice training for direct services to these children. Therefore, we explored the preservice and in-service training experiences of AAC practitioners to inform improvements in practitioner training and ultimately improve services for individuals with complex communication needs.

Method

A focus group study was conducted with AAC practitioners (three focus groups with 13 AAC practitioners in total) in one midwestern U.S. state to explore preservice and in-service training experiences and gain knowledge to inform future training efforts. Constant comparative analysis was used to analyze data gathered from the focus groups.

Results

This study highlighted important gaps in preservice and in-service training for AAC practitioners, barriers related to AAC training, and suggestions for improving AAC training.

Conclusions

This study provides important insights into ways AAC practitioner training might improve. We provide clinical implications and future research directions to continue improving AAC practitioner preparation and subsequent services for individuals with complex communication needs.
What Do I Do Now? Resolving School-Based Ethical Challenges
Authors: Power-deFur Lissa A.
Published: February 2020

Purpose

The purpose of this article is to present a commonly used ethical decision-making approach and apply it to ethical situations commonly encountered by school-based clinicians. The application of a multistep model enables the individual to explore ethical dilemmas through fully understanding the situation and analysis of resources. These steps, followed by brainstorming, facilitate the speech-language pathologist's ability to arrive at a positive solution.

Conclusion

School-based speech-language pathologists deal with a variety of ethical dilemmas. Resolution can take many forms, including application of federal and state policies; professional development; and, perhaps most importantly, conversations with colleagues and administrators. The more positive solutions stem from a thorough review of the issue and policies influencing the issue followed by brainstorming a variety of potential approaches.
Enhanced flow sensing with interfacial microstructures
Authors: Jiang Yonggang , Zhao Peng , Ma Zhiqiang , Shen Dawei , Liu Gongchao , Zhang Deyuan
Published: February 2020

Biological flow receptors show astonishing performance and are used as models for the design of novel flow sensors. However, the functional importance of interfacial microstructures is seldom discussed in previous review papers. Herein, this review summarises the underlying biomechanical principles in the biological flow receptors and describes the recent progress in bio‐inspired flow sensors, in which the underlying sensing‐enhancement mechanisms are emphasised.
Classification model for predictive maintenance of small steam sterilisers
Authors: Musabayli Musagil , Osman Mohd Hafeez , Dirix Michael
Published: February 2020

With 35,000 small steam sterilisers in the German market, after‐sales service and maintenance are critical issues for manufacturers and distributors. At present, preventive maintenance is one of the most commonly‐implemented maintenance strategies. However, with an average failure probability of 10%, ∼3500 autoclaves require unplanned repair per year, causing customers’ business interruptions and increased maintenance costs. From the authors’ observation, a predictive failure detection mechanism is needed to prevent failures and reduce the significant safety risk. Hence, this study proposes a predictive maintenance mechanism for small steam sterilisers. The predictive maintenance mechanism is constructed from classification models that categorised the health condition of two critical components in small steam sterilisers, i.e. a vacuum pump and a steam generator. The classification models were built from multisensory data, obtained from 1000 protocol records of CertoClav Vacuum Pro steam sterilisers. They perform exploratory experiments to find a suitable classification model. This study found that the random forest algorithm performed best in terms of accuracy for both the vacuum pump and steam generator data sets (83.5 and 82.0%, respectively). They also found that the features related to the pre‐vacuum stage profoundly influence the condition of the vacuum pump and the steam generator.
Blockchain: A distributed solution to UAV‐enabled mobile edge computing
Authors: Guan Zhenyu , Lyu Hanzheng , Li Dawei , Hei Yiming , Wang Tongchen
Published: February 2020

Mobile edge computing (MEC) is to process, analyse, store and calculate the network data at the edge of the network. When the ground infrastructure is damaged in an emergency, the unmanned aerial vehicle (UAV) formation can be rapidly deployed to undertake the task of MEC. However, there are some potential problems to be considered in UAV‐enabled MEC, such as the trust among UAVs from different sources and the stability of UAV formation network. In view of the problems existing, this study proposes a blockchain‐based architecture to build a system of mutual trust, fairness, openness, and stability in this scenario. Through the implementation of blockchain technology, key data such as device computing capacity, task allocation, and task execution process are recorded openly, transparently, and irrevocably. As multi‐party trust is built to reduce the occurrence of fraud, system participants can get a reasonable reward. On this basis, the smart contract is used to ensure that algorithms are accessible to the public, and the sub‐blockchain technology improves the stability of the system. In the case study, the simulation results show that the resource consumption and time cost of the proposed scheme is reasonable and feasible.
Hijacking internet‐connected devices to provoke harmful oscillations in an electrical network: a feasibility assessment
Authors: Gowing Hugh , Cuffe Paul
Published: February 2020

Internet‐connected devices will represent an increasing proportion of the load served by electric power systems. As these devices could conceivably be hijacked and controlled remotely by a malicious actor, they could represent a new threat vector against the dynamic security of a power system. Such attack strategies have not been considered in the existing literature on power system cybersecurity. As an initial scoping exercise, the present case study explores whether such devices could be remotely hijacked and then maliciously power‐cycled at particular frequencies to deliberately provoke harmful oscillations in an electrical grid. To gauge the broad feasibility of this novel style of attack, dynamic simulations are performed on two representative test power systems, at differing levels of attacker and defender resources. These simulations show that power‐cycling just 1% of consumer loads at a system's resonant frequency may sometimes provoke harmful electromechanical oscillations throughout a national grid. This novel simulation exercise, therefore, implies that cybersecurity vulnerabilities at the consumer side could jeopardise the physical integrity of a nation's entire electricity supply.
Adaptive quantised control of uncertain non‐linear systems with state constraints and time‐varying delays
Authors: Xia Xiaonan , Kang Guanpeng , Zhang Tianping , Fang Yu
Published: February 2020

This study proposes an adaptive quantised fuzzy control strategy for a class of non‐linear systems with time‐varying delay, state constraints, and input unmodelled dynamics. Design difficulties focus on the fact that the input‐quantised actuator possesses both unknown control gain and non‐linear input unmodelled dynamics, and all the states are required to satisfy state constraints. To remove these obstacles, integral barrier Lyapunov functions combined with Nussbaum functions are designed to deal with the unknown control gains and state constraints, and a quantised controller combined with the normalised signal is developed to tackle the quantised input and input unmodelled dynamics. To avoid the chattering and reduce the quantisation error in a wide scope of the control volume, a novel logarithmic uniform hysteresis quantiser is employed, which has both advantages of the existing uniform quantiser and hysteresis quantiser. Two simulation examples of practical control systems are conducted to demonstrate the effectiveness of the proposed control protocol.
Design optimisation of submersible permanent magnet synchronous motor by combined DOE and Taguchi approach
Authors: Cui Junguo , Xiao Wensheng , Zou Wenqiang , Liu Simiao , Liu Qi
Published: February 2020

This study presents an optimisation procedure for a submersible permanent magnet synchronous motor (PMSM) to achieve the maximum efficiency and minimum cogging torque simultaneously. Numerous geometric parameters can be used to define submersible PMSM. To identify the most significant parameters for optimisation, the fractional factorial design out of design of experiment (DOE) is employed for the screening activity, considering the interaction effects into account. The manufacturing process of the motor causes dimension tolerances, shape and position tolerances, installation errors and deviations of material properties. To ensure a good robustness for the performance of the submersible PMSM, Taguchi's robust design method is employed. The screened significant parameters are taken as the control factors. The noise factors include inner diameter of stator, the air‐gap length, the remanence of the magnets and the dimension tolerances of magnets. Numerical results demonstrate that this method is an effective optimisation design procedure to improve the performance of submersible PMSM, which is finally proved by the prototype test.
Method for extracting current envelope for broken rotor bar fault detection of induction motors at time‐varying loads
Authors: Wang Panpan , Lu Junjie , Shi Liping , Zhang Yang , Tong Zhigang , Wang Nanding
Published: February 2020

When the broken rotor bar (BRB) fault occurs in induction motors, the amplitude of stator fundamental current is modulated by fault components, forming the current envelope with a particular frequency, which can be considered as a powerful criterion for BRB detection. However, it is relatively difficult to extract especially at time‐varying loads due to the non‐stationary characteristics. Thus, a novel envelope extraction method (EEM) combining fast Fourier transform and sliding overlapping window is proposed and the overall performance is tested by simulation. The results show that the method is capable to effectively extract the current envelope, but the extraction accuracy is unsatisfied due to the spectrum leakage in the case of non‐integer periodic truncation. The technique of discrete spectrum correction is then introduced into EEM to improve its extraction accuracy, and then, an improved EEM (IEEM) is proposed and then tested by simulation. The results show that the IEEM is able to eliminate the impact of non‐integer periodic truncation, effectively and accurately extract the current envelope. Finally, the two methods are applied in BRB fault online detection of 1.1 and 2.2 kW induction motors at time‐varying loads. The corresponding experimental results demonstrate its validity and universality again.
Novel modelling method based on winding sub‐element of direct‐drive permanent magnet synchronous motor
Authors: Gao Caixia , Lv Ke , Si Jikai , Feng Haichao , Gan Chun
Published: February 2020

Owing to its many benefits, including convenient and short computing time, the analytical model (AM) is widely used in the performance analyse of the permanent magnet synchronous motor (PMSM). The existing analytical models based on phase winding cannot sufficiently speculate about the contribution of the coil to the performances of direct‐drive PMSM (DDPMSM) with series coils and multiple branches. Hence, in this work, a novel AM for the DDPMSM is proposed. This model, which is based on the winding sub‐element, can analyse the influence of coil on motor performance. First, the structure and key parameters of the DDPMSM are reported. Second, an inductance matrix, which considers the spatial disposition of coils and the characteristics of large self‐inductance and small mutual inductance, is constructed. Then, the influence of the coil on motor performance is analysed based on the proposed AM. Finally, the results of AM, finite‐element model and experiment are compared. The results validate the correctness of the proposed AM. Furthermore, the proposed AM can speculate about the contribution of a coil in the DDPMSM performances with satisfactory accuracy.
Microgrid frequency regulation involving low‐wind‐speed wind turbine generators based on deep belief network
Authors: Bian Xiaoyan , Zhang Jingxian , Ding Yang , Zhao Jian , Zhou Qibin , Lin Sunfu
Published: February 2020

With the development of low‐wind‐speed technology, it becomes a trend that low‐wind‐speed wind turbine generators (LWTGs) are integrated into a microgrid. However, the frequency stability of the microgrid has thereby been challenged since the increased penetration of wind power lowers the inertia of the microgrid. In order to investigate how LWTGs can effectively participate in suppressing the frequency fluctuation of the microgrid, virtual inertia control, over‐speed control, as well as droop control, is applied to LWTG. Moreover, the de‐loading ratio of over‐speed control, along with the control parameters of virtual inertia control and droop control are all optimised under different wind speeds by virtue of the deep belief network, whereas the problem of over‐speed control failure with the scheme of fixed de‐loading ratio becomes more pronounced under low‐wind speeds, which is defined as a blind area problem. To solve this problem, on the one hand, the strategy of the variable de‐loading ratio is adopted under low‐wind‐speeds. On the other hand, the concepts of the minimum and maximum critical wind speed are deduced through theoretical analysis, which greatly restricts the number of feasible solutions of de‐loading ratio under different wind speeds so as to improve the optimisation efficiency about 50%.
Latest advances in optical frequency combs based on quadratic non‐linearity
Authors: Mariana Barturen , Benjamin Maglio , Pablo Alejandro Costanzo Caso
Published: February 2020

Second‐order non‐linear susceptibility () is the cause of many non‐linear processes in optics including second harmonic generation, sum frequency generation and difference frequency generation. Optical frequency combs based on , i.e. quadratic frequency combs, hold the promise of reducing the devices power consumption and footprint since materials present a stronger non‐linearity than materials, which suggests that higher efficiencies can be achieved. In this work, we will revisit the latest quadratic combs experimental advances, concerning power threshold, span and wavelength conversion efficiency.
Photonic integrated circuits for terahertz source generation
Authors: Hou Lianping , Tang Song , Hou Bin , Marsh John H.
Published: February 2020

The authors introduce four kinds of terahertz photonics components based on photonic integrated circuits (PICs). A PIC‐based integrated optoelectronic synthesiser for THz communications is described, which can be tuned continuously over the range 0.254–2.723 THz using photomixing. A laterally‐coupled dual‐grating distributed feedback laser (DFB) diode integrated with an electroabsorption modulator is used to generate an 820 GHz beat signal. THz signal production is reported using a dual‐wavelength DFB diode laser with a two‐section phase‐shifted sampled Bragg grating. Finally, a THz source at 640 GHz, based on a sampled grating distributed Bragg reflector semiconductor mode‐locked laser diode, is reported offering superior reproducibility, controllability, and a wider operation range than other reported mode‐locked THz laser diodes. Each of these sources is a monolithic construction emitting light at 1.5 µm. The light can be amplified in an erbium‐doped fibre amplifier, delivered over silica optical fibre and used to generate THz radiation via a photodiode antenna or photoconductive antenna in a remote location.
Double‐image asymmetric cryptosystem using cylindrical diffraction and spectrum fusion and compression
Authors: He Changtao , Liu Zhigang , Chen Xudong , Wang Jun
Published: February 2020

A double‐image asymmetric cryptosystem is proposed by using cylindrical diffraction and spectrum fusion and compression in the zigzag‐scanned domain of discrete cosine transform (DCT). First, each plaintext of double image is converted into spectrum coefficients (SCs) by DCT, and the SCs are zigzag scanned. Second, the first 1/4 of SCs is resized to two low‐frequency images, the second 1/4 of SCs is resized to two high‐frequency images, while the last 1/2 of SCs is discarded. Third, the two low‐frequency and two high‐frequency images are fused and merged into three rounds of encryption process by using the complex combination, random phase encoding, and phase reserving–truncation in the cylindrical diffraction transform domain. Finally, the plaintexts of the double image are successfully encrypted into a ciphertext and three private keys with each only 1/8 and totally 1/2 of the size of the plaintext, which gains a high compression efficiency. In the proposed cryptosystem, the quality of the reconstructed image is improved due to the compression in the zigzag‐scanned DCT domain, and the security is improved owing to the asymmetric cylindrical diffraction and spectrum‐fusion algorithm. The effectiveness and flexibility of the proposed cryptosystem have been validated by the numerical simulation results.
Unambiguous velocity estimation method based on intra‐pulse cross‐correlation
Authors: Zhang Yunjian , Pan Pingping , Fu Maozhong , Deng Zhenmiao , Zhang Yixiong , Liu Hui
Published: February 2020

In this study, by employing the intra‐pulse cross‐correlation (IPCC) operation, an unambiguous velocity estimation method is proposed for narrow‐band long‐range radars with high carrier frequency and low pulse repetition frequency. This estimation algorithm is simple and could be easily implemented in existing radar systems without changing the radar hardware or the pulse transmitting scheme. Comparing with the slow time dimension correlation algorithm, the accuracy of the proposed intra‐pulse frequency domain method is greatly improved, and the brute‐force search for the unknown motion parameters is also unnecessary. By first setting a small frequency offset of the IPCC operation, the unambiguous velocity region could be significantly enlarged. Using the relatively coarse but unambiguous estimates and increasing the frequency offset step by step, the IPCC is repeatedly applied to obtain more accurate estimates. Note that the estimation results of the IPCC algorithm could be used in the maximum‐likelihood estimator for ambiguity resolution. The Cramér‐Rao bound for the proposed algorithm is derived, and the optimal frequency offset in the sense of estimation accuracy is also analysed. Through numerical simulations for both synthetic and real radar data, the effectiveness of the proposed estimation algorithm is verified.
The WISSH quasars project
Authors: Travascio A. , Zappacosta L. , Cantalupo S. , Piconcelli E. , Arrigoni Battaia F. , Ginolfi M. , Bischetti M. , Vietri G. , Bongiorno A. , D’Odorico V. , Duras F. , Feruglio C. , Vignali C. , Fiore F.
Published: February 2020

Context.In recent years, Lyαnebulae have been routinely detected around high redshift, radio-quiet quasars thanks to the advent of the highly sensitive integral field spectrographs. Constraining the physical properties of the Lyαnebulae is crucial for a full understanding of the circum-galactic medium (CGM). The CGM acts both as a repository for intergalactic and galactic baryons as well as a venue of feeding and feedback processes. The most luminous quasars are privileged test-beds to study these processes, given their large ionising fluxes and dense CGM environments in which they are expected to be embedded.

Aims.We aim to characterise the rest-frame ultraviolet (UV) emission lines in the CGM around a hyper-luminous, broad emission line, radio-quiet quasar atz ∼ 3.6, which exhibits powerful outflows at both nuclear and host galaxy scales.

Methods.We analyse VLT/MUSE observations of the quasar J1538+08 (Lbol = 6 × 1047erg s−1), and we performed a search for extended UV emission lines to characterise its morphology, emissivity, kinematics, and metal content.

Results.We report the discovery of a very luminous (∼2 × 1044erg s−1), giant Lyαnebula and a likely associated extended (75 kpc) CIV nebula. The Lyαnebula emission exhibits moderate blueshift (∼440 km s−1) compared to the quasar systemic redshift and a large average velocity dispersion (σ¯v∼ 700 km s−1) across the nebula, while the CIV nebula shows average velocity dispersion ofσ¯v∼ 350 km s−1. The Lyαline profile exhibits a significant asymmetry towards negative velocity values at 20−30 kpc south of the quasar and is well parametrised by the following two Gaussian components: a narrow (σ ∼ 470 km s−1) systemic one plus a broad (σ ∼ 1200 km s−1), blueshifted (∼1500 km s−1) one.

Conclusions.Our analysis of the MUSE observation of J1538+08 reveals metal-enriched CGM around this hyper-luminous quasar. Furthermore, our detection of blueshifted emission in the emission profile of the Lyαnebula suggests that powerful nuclear outflows can propagate through the CGM over tens of kiloparsecs.
From stellar coronae to gyrochronology: A theoretical and observational exploration
Authors: Ahuir J. , Brun A. S. , Strugarek A.
Published: February 2020

Context.Stellar spin down is the result of a complex process involving rotation, dynamo, wind, and magnetism. Multiwavelength surveys of solar-like stars have revealed the likely existence of relationships between their rotation, X-ray luminosity, mass losses, and magnetism. They impose strong constraints on the corona and wind of cool stars.

Aims.We aim to provide power-law prescriptions of the mass loss of stars, of their magnetic field, and of their base coronal density and temperature that are compatible with their observationally-constrained spin down.

Methods.We link the magnetic field and the mass-loss rate from a wind torque formulation, which is in agreement with the distribution of stellar rotation periods in open clusters and the Skumanich law. Given a wind model and an expression of the X-ray luminosity from radiative losses, we constrained the coronal properties by assuming different physical scenarios linking closed loops to coronal holes.

Results.We find that the magnetic field and the mass loss are involved in a one-to-one correspondence that is constrained from spin down considerations. We show that a magnetic field, depending on both the Rossby number and the stellar mass, is required to keep a consistent spin down model. The estimates of the magnetic field and the mass-loss rate obtained from our formalism are consistent with statistical studies as well as individual observations and they give new leads to constrain the magnetic field-rotation relation. The set of scaling-laws we derived can be broadly applied to cool stars from the pre-main sequence to the end of the main sequence (MS), and they allow for stellar wind modeling that is consistent with all of the observational constraints available to date.
The first blazar observed at z > 6
Authors: Belladitta S. , Moretti A. , Caccianiga A. , Spingola C. , Severgnini P. , Della Ceca R. , Ghisellini G. , Dallacasa D. , Sbarrato T. , Cicone C. , Cassarà L. P. , Pedani M.
Published: February 2020

We present the discovery of PSO J030947.49+271757.31, the radio brightest (23.7 mJy at 1.4 GHz) active galactic nucleus (AGN) at z >  6.0. It was selected by cross-matching the NRAO VLA Sky Survey and the Panoramic Survey Telescope and Rapid Response System PS1 databases and its high-z nature was confirmed by a dedicated spectroscopic observation at the Large Binocular Telescope. A pointed Neil Gehrels Swift Observatory XRT observation allowed us to measure a flux of ∼3.4 × 10−14 erg s−1 cm−2 in the [0.5–10] keV energy band, which also makes this object the X-ray brightest AGN ever observed at z >  6.0. Its flat radio spectrum (ανr <  0.5), very high radio loudness (R >  103), and strong X-ray emission, compared to the optical, support the hypothesis of the blazar nature of this source. Assuming that this is the only blazar at this redshift in the surveyed area of sky, we derive a space density of blazars at z ∼ 6 and with M1450 Å < −25.1 of 5.5+11.2−4.6 × 10−3 Gpc−3. From this number, and assuming a reasonable value of the bulk velocity of the jet (Γ = 10), we can also infer a space density of the entire radio-loud AGN population at z ∼ 6 with the same optical/UV absolute magnitude of 1.10+2.53−0.91 Gpc−3. Larger samples of blazars will be necessary to better constrain these estimates.
Semi-Empirical Method for evaluating Risk of Liquefaction during earthquakes a Study Case of Rhiss Dam
Authors: Latifi Fatima Ezzahraa , Baba Khadija , Bahi Lahcen , Touijrate Soukaina , Cherradi Choukri
Published: February 2020

Liquefaction is a hazardous and temporary phenomenon by which water saturated soil loses some or all of its resistance. The undrained conditions linked to the cyclic load increase the pores water pressure inside the soil and consequently reduce effective stress. As a result, the soil can no longer resist or hold the shear forces, and lead to enormous deformations that directly influence the stability of structures and infrastructures foundations. Since 1964, several semi-empirical methods have been invented to evaluate the liquefaction potential using the in-situ test results. This study is based on the correlation between experimental data results of Menard pressuremeter and SPT dynamic penetrometer tests. Samples used in this test come from the Rhiss dam located in the North of Morocco, 24 kilometers as the crow flies from the town of Al Hoceima and south of the foundations of a calcareous ridge. The studied area have high seismic activity and a high percentage of fine soil elements, which suggests the possibility of soil liquefaction. We present and discuss the results of applying Idriss and Boulanger, and Youd et al methods in the evaluation of liquefaction susceptibility.
Food preferences of Pike Perch, Sander lucioperca (Linnaeus, 1758) in Morocco
Authors: Bousseba Meriem , Ferraj Loubna , Ouahb Sara , Ouizgane Anouar , El Moujtahid Aziz , Droussi Mohammed , Hasnaoui Mustapha
Published: February 2020

Sander luciopercahasbeen introduced in Morocco since 1939. This noble fish has shown a good ability to acclimatize to Moroccan conditions and has developed well [1]. The present study examines diet composition and predator-prey relationships that are dependent on size and weight between sander and its preys during the period October 2018-April 2019. Stomach contents of 287 specimens, whose size varies between 17 and 72 cm, from Al-Massira dam, wereanalyzed. The results showed that Sander feeding is composed of six categories of prey, the most important species was the Blue gill (Perch) with an occurrence index equal to 14.9%, the occurrence indices for other preys were respectively : Pike perch (8.01%), Tilapia (5.57%), Roach (0.69%), Black bass (0.69%) and Common carp (0.69%). It has been found that the total length of the preys increases with that of the Pike perch. Thus, the Pike perch is able to ingest preys of big weight and size. We also revealed that cannibalism was high, indicating a lack of forage fish in this lake.
The Distribution of Malaria with Seasonal in Kokap Yogyakarta 2012-2017
Authors: Lestari Raden A.K. , Lusiyana Novyan , Nurochmah Fitria S.
Published: February 2020

Kokap is one of the endemic areas of malaria in Yogyakarta. The transmission of malaria was influenced by multiple factors including season. The impact of the rainfall rate in the rainy season was increasing the breeding place of vector-borne diseases, especially malaria. This study aims to describe the case of malaria, the relationship with season and mapping of endemic areas of malaria in Kokap I Primary Health Centre at Kulon Progo in 2012-2017. This is a descriptive epidemiological study with an ecological study approach. The study population was malaria cases in Kokap I Primary Health Centre. Data were analyzed descriptively and then mapped based on the endemic areas. The result showed 245 cases of malaria consisting of 136 men (55.5%) and 109 women (44.5%), on which 166 of them were in 15-45 years age group (67.7%). There were 59.2% of patients were positive of P. vivax infection and 40% of patients were positive of P. falciparum. Malaria cases in 2012-2017 at rainy season, moist season, dry season were 109, 59 and 77 respectively. Malaria cases were increased from October to April which is the rainy season, but there is no significant difference between rainy season and dry season with the incidence of malaria (p=0.316). Kalirejo village was found as a medium-high endemic village, while Hargomulyo and Hargorejo Villages were lowmedium endemic villages. During 2012-2017, we found that malaria in Kokap was dominated with P. vivax infection and the malaria incidence was increased in the rainy season.
Identification and Characterization of Protamine1 Gene in Aceh Cattle
Authors: Helmi Teuku Z. , Hambal Muhammad , Sugito Sugito , Zamzami Rumi S. , Rusli Rusli , Akmal Muslim
Published: February 2020

Naturally, the fertility of Aceh cattle has declined and caused huge losses in the development of Aceh cow germplasm. Several genetic-based studies have been carried out in Aceh cattle, including characteristics of genetic diversity using microsatellite DNA and its relationship to body weight in Aceh cows, but there is no research on genomics that is closely related to fertility, especially fertility in aceh cows. Previous studies have revealed a correlation between fertility with the expression of several genes involved in spermatogeneses such as Protamines (PRM 1, 2, and3) and Transition Nuclear Proteins (TNPS 1 and 2). This study aims to identify thePRM1gene that plays an important role in spermatogenesis and the fertility status of Aceh cattle. This research was carried out using 10 Aceh cattle testes taken from slaughterhouses, followed by DNA isolation, amplification of thePRM1gene, DNA sequencing, and DNA base sequence analysis. The result showed that the nucleotide sequences of aceh cattlePRM1gene did not differ from thePRM1gene fromBos taurusandBos indicusin the GeneBank. Analysis of protein sequences showed thatPRM1in Aceh cattle sperm is rich in the amino acid arginine, which is 36.92%. From this study, it can be concluded that thePRM1 genefrom Aceh cattle is identical to thePRM1gene fromBos taurusandBos indicusboth at the DNA sequence level and at the protein sequence.
Acute Toxicity Test of Pigeon Pea Leaves Extract (Cajanus cajan) in Rats
Authors: Wresdiyati Tutik , Stephany Stephany , Handharyani Ekowati , Sa’diah Siti , Astawan Made
Published: February 2020

Acute toxicity test was conducted to evaluate the safety level of pigeon pea (Cajanus cajan) leaves extract, using the Organisation for Economic Co-operation and Development (OECD 423) guideline method. The pigeon pea leaves were extracted using 96%ethanol as a solvent. A total of 9 male rats were used divided into 3 groups: 1 control group and 2 treatment groups. The rat in control group (group 1) received a single dose of distilled water while the rat in groups 2 and 3 received a single dose of pigeon pea leaves extract at doses of 300 mg/kg BW and 2000 mg/kg BW, respectively. The aquadest and extract suspension were administered orally using rat stomach tubedos. Mortality and clinical signs were examined in the first 4 hours (critical time), 24 hours, and 14 days after the treatments. The result revealed that the LD50 values of the extract was estimated at more than 5000 mg/kg BW and classified as practically nontoxic.
Comparison of Estrous Performance and Progesterone Level of Kacang Goats Induced by PGF2α Versus Ovsynch Protocol
Authors: Panjaitan Budianto , Dewi Almira , Nasution Fadli FR , Adam Mulyadi , Siregar Tongku N. , Thasmi Cut N. , Syafruddin Syafruddin
Published: February 2020

This study aimed to compare estrous performance and progesterone concentration during the estrous cycle of kacang goats induced by PGF2α versus ovsynch protocol. This research used six female kacang goats. The goats were divided into two groups namely the K1 group which was induced by injecting 7.5 mg PGF2α intramuscularly in 10 days interval and K2 group which was induced by using the ovsynch method. Protocol for K2 group was as follow; at day 1, the goats were injected with 7.5 mg PGF2α; at day 8, they were injected with 50 µg GnRH; at day 15 they were injected with 7.5 mg PGF2α; at day 18 they were injected with 50 µg GnRH. Estrous were detected using male goat and visual observation. The blood samples were taken on days 7, 14, and 21 after estrous. Progesterone concentration was measured with enzyme-linked immunosorbent assay (ELISA) technique. Intensity, onset, and duration of estrous in K1 group versus K2 group were 8.33±2.08 vs 7.00±1.00; 56.00±34.12 vs 36.00±20.78 hours; and 24.00±26.15 vs 24.00±20.78 hours, respectively (p>0.05). Level of progesterone hormone on day 7, 14, and 21 for K1 vs K2 were 0.812±0.710 vs 2.369±3.351; 5.051±7.754 vs 3.091±4.385 ng/ml; and 4.173±6.692 vs 3.562±4.113 ng/mL, respectively (p>0,05). It can be concluded that the differences in synchronization protocols between PGF2α versus ovsynch do not affect the performance of estrous and the concentration of progesterone during the estrous cycle of kacang goats.
Experimental study of a hybrid solar photovoltaic, thermoelectric and thermal module
Authors: Matias Flávio , Pires Luís C. , Silva Pedro D. , Gaspar Pedro D.
Published: February 2020

Nowadays, solar energy, which can be photovoltaic and thermal, is a clean and reliable source of energy for the production of electric and thermal power. However, new ways for improving photovoltaic efficiency are fundamental for an extensive application of this technology. Most of the energy absorbed by the PV panel converts itself into heat, which usually is lost and does not have any energetic value. The performance of a combined photovoltaic (PV), thermoelectric generator (TEG) and water heating panel is tested in practice. The thermoelectric set is applied on the back of the PV panel so that the two devices have approximately the same temperature. On the other face of the thermoelectric set, there is the water heating panel, which consists of an aluminium heat exchanger specially designed for this hybrid module. The exposed surface of the hybrid panel has an area of about 2.72 dm2. Experimental tests were conducted in direct solar exposure during July. The experimental results indicate that the maximum global module efficiency was 91.3% for an irradiance of 1089 W/m2. The power peak production was 29.7 W, at 2 p.m., with an irradiance value of 1230 W/m2.
Succinct Review on State-of-art Carbon-based Phase Change Material for Solar Thermal Storage Applications
Authors: Ishola Felix , Babalola Philip , Olatunji Obafemi , Ogunrinola Iyanuoluwa , Ayo Olayinka , Akinlabi Stephen
Published: February 2020

Radiation from the sun continually generates enormous solar energy reaching the atmosphere and then radiates back into the outer space over a while. The energy source is considered to be potential renewable thermal energies if effectively harnessed and stored. Thermal energy storage could be in either cold or heat form for later use for either cooling and heating purposes respectively; it can also be utilized for electricity production. The development of highly efficient and cost-effective heat storage materials has been an emerging school of thought for researches into smart methods of heat storage. The authors briefly review the state-of-art carbon-based composite phase change materials (PCM) that have been employed in applications that are related to thermal storage. Various types of recently developed carbon composites with improved thermal storage properties have been succinctly discussed. The technological implications of employing the identified materials in the thermal storage applications were also highlighted and discussed.
Computational Intelligence Based Technique for Multi-DG Installation in Transmission System
Authors: Sahilahudin Muhamad Fazrizal Faiz , Musirin Ismail , Jelani Shahrizal , Mansor Mohd Helmi
Published: February 2020

The increasing electricity demand in transmission system has caused the power transmission system experiencing stress condition. This phenomenon has forced the system to need urgent additional supply to maintain system adequacy, in particular the de-regulated power system environment. Distributed generation (DG) has been identified as one of the possible solutions to address this issue. DG installation has the capability to reduce transmission loss and improve the voltage profile. This paper presents evolutionary programming (EP) technique for optimizing the sizing and locations in DG installation. In this study, several DGs have been installed to address the voltage profile improvement and loss minimization; implemented on the IEEE 30-Bus Reliability Test System (RTS). Results obtained from the study revealed that, installation of multi-DGs in a transmission system has significantly minimized the transmission loss along with voltage profile improvement.
Optimising Production through Intelligent Manufacturing
Authors: Olalere Isaac O. , Olanrewaju Oludolapo A.
Published: February 2020

Intelligent manufacturing system (IMS) has been the focus of most industries since Industry 4.0 revolution. IMS is being implemented through the integration of Internet of Things, (IoT), Cyber-Physical Systems (CPS), digital twin and big data analytics to optimize production through smart manufacturing. This research presents a conceptual approach of an adaptive clustering algorithm (ACA) for advanced manufacturing decision-making for smart machining manufacturing. The work considers product monitoring and assessment, machine health and operating parameters monitoring, as an important factor for intelligent decision making on a machining production line through the developed cyber twin of the machine tool for production optimisation. Cyber twin of the machine tool is developed which runs on a realtime sequence with the physical asset fussed with smart sensors and controllers enabled with cloud computing, IoT and data analytics. The ACA enables resources monitoring, production monitoring, machine condition monitoring, cloud feedback notification, product monitoring, and assessment, for intelligent decision-making from a cluster of similar machines using ANN clustering tool for self-aware, self-predict and self-reconfiguration in a smart machining production line to detect a cutting tool chipping of less than 0.25mm size. The method is proposed to optimise production by increasing productivity through intelligent decision and prediction for tool change, tool failure, maintenance, adjustment of operating parameters.