bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced microbial stability in the active layer is associated with carbon loss under alpine permafrost degradation
Authors: Wu Ming-Hui , Chen Sheng-Yun , Chen Jian-Wei , Xue Kai , Chen Shi-Long , Wang Xiao-Ming , Chen Tuo , Kang Shi-Chang , Rui Jun-Peng , Thies Janice E. , Bardgett Richard D. , Wang Yan-Fen 
Published: June 2021

Significance
Permafrost degradation may induce soil carbon (C) loss, critical for global C cycling, and be mediated by microbes. Despite larger C stored within the active layer of permafrost regions, which are more affected by warming, and the critical roles of Qinghai–Tibet Plateau in global C cycling, most previous studies focused on the permafrost layer and in high-latitude areas. Here, we demonstrate in situ that permafrost degradation alters the diversity and potentially decreases the stability of active layer microbial communities. Additionally, these changes are associated with soil C loss and potentially a positive C feedback. This study provides insights into microbial-mediated mechanisms responsible for C loss within the active layer in degraded permafrost, aiding in the modeling of C emission under future scenarios.
Paradoxical stabilization of relative position in moving frames
Authors: Özkan Mert , Anstis Stuart , ’t Hart Bernard M. , Wexler Mark , Cavanagh Patrick 
Published: June 2021

Significance
Every eye movement drags the visual scene over our retinas and yet nothing appears to move. We now report a small-scale version of this visual stability with a square frame moving on a monitor in a well-lit room. Probes flashed before and after the frame’s motion are also stabilized in the frame’s coordinates—as if the frame were stationary—shifting perceived locations by up to half the screen’s width from their physical locations. Paradoxically, with these small frames, this ∼100% stabilization occurs despite visible frame motion. Unlike motion-induced position shifts, frame-induced shifts are independent of speed and depend instead on the distance the frame travels. This powerful discounting of motion may reveal a critical component of visual stability.
Vibrational relaxation dynamics in layered perovskite quantum wells
Authors: Quan Li Na , Park Yoonjae , Guo Peijun , Gao Mengyu , Jin Jianbo , Huang Jianmei , Copper Jason K. , Schwartzberg Adam , Schaller Richard , Limmer David T. , Yang Peidong 
Published: June 2021

Significance
Halide perovskites, especially layered perovskites, offer a number of advantages to creating bright and efficient light-emitting devices and other optoelectronic applications. The organic–inorganic hybrid layered perovskite features complex lattice dynamics due to the ionic character of the crystal and the softness arising from noncovalent bonds between molecular moieties and the inorganic network. Especially, the packing geometry of the organic barriers leads to a structural deformation of inorganic octahedral, which strongly affects the properties that are crucial for device applications. In this work, we use high-resolution resonant impulsive stimulated Raman spectroscopy of a variety of ligand substitutions in layered perovskites. We find the composition of organic ligands can substantially change the dephasing rate of optical phonons and their temperature dependence, due to varying degrees of anharmonicity in the lattice and dynamic structural disorder.
Characterization of angularly resolved EUV emission from 2-µm-wavelength laser-driven Sn plasmas using preformed liquid disk targets
Authors: Schupp R , Behnke L , Bouza Z , Mazzotta Z , Mostafa Y , Lassise A , Poirier L , Sheil J , Bayraktar M , Ubachs W , Hoekstra R , Versolato O O 
Published: June 2021

Abstract
The emission properties of tin plasmas, produced by the irradiation of preformed liquid tin targets by several-ns-long 2 µm-wavelength laser pulses, are studied in the extreme ultraviolet (EUV) regime. In a two-pulse scheme, a pre-pulse laser is first used to deform tin microdroplets into thin, extended disks before the main (2 µm) pulse creates the EUV-emitting plasma. Irradiating 30- to 300 µm-diameter targets with 2 µm laser pulses, we find that the efficiency in creating EUV light around 13.5 nm follows the fraction of laser light that overlaps with the target. Next, the effects of a change in 2 µm drive laser intensity (0.6–1.8 × 1011 W cm−2) and pulse duration (3.7–7.4 ns) are studied. It is found that the angular dependence of the emission of light within a 2% bandwidth around 13.5 nm and within the backward 2π hemisphere around the incoming laser beam is almost independent of intensity and duration of the 2 µm drive laser. With increasing target diameter, the emission in this 2% bandwidth becomes increasingly anisotropic, with a greater fraction of light being emitted into the hemisphere of the incoming laser beam. For direct comparison, a similar set of experiments is performed with a 1 µm-wavelength drive laser. Emission spectra, recorded in a 5.5–25.5 nm wavelength range, show significant self-absorption of light around 13.5 nm in the 1 µm case, while in the 2 µm case only an opacity-related broadening of the spectral feature at 13.5 nm is observed. This work demonstrates the enhanced capabilities and performance of 2 µm-driven plasmas produced from disk targets when compared to 1 µm-driven plasmas, providing strong motivation for the use of 2 µm lasers as drive lasers in future high-power sources of EUV light.
On the formation of antihydrogen beams using travelling optical lattices
Authors: Madsen N , Charlton M 
Published: June 2021

Abstract
The production of beams of antihydrogen atoms using the dipole force provided by a travelling optical lattice to accelerate a sample of the anti-atoms held in a magnetic gradient atom trap is investigated. By considering current and near-future antihydrogen trapping capabilities we find that useful fluxes of the anti-atoms can be achieved with directional properties that can be manipulated using laser parameters such as pulse duration and frequency chirp rate. Applications of the beams are briefly discussed.
Decoupling of asymmetric dark matter during an early matter dominated era
Authors: Chanda Prolay , Unwin James 
Published: June 2021

Abstract
In models of Asymmetric Dark Matter (ADM) the relic density is set by a particle asymmetry in an analogous manner to the baryons. Here we explore the scenario in which ADM decouples from the Standard Model thermal bath during an early period of matter domination. We first present a model independent analysis for a generic ADM candidate with s-wave annihilation cross section with fairly general assumptions regarding the origin of the early matter dominated period. We contrast our results to those from conventional ADM models which assume radiation domination during decoupling. Subsequently, we examine an explicit example of this scenario in the context of an elegant SO(10) implementation of ADM in which the matter dominated era is due to a long lived heavy right-handed neutrino. In the concluding remarks we discuss the prospects for superheavy ADM in this setting.
Online detection of movement during natural and self-initiated reach-and-grasp actions from EEG signals
Authors: Pereira Joana , Kobler Reinmar , Ofner Patrick , Schwarz Andreas , Müller-Putz Gernot R 
Published: June 2021

Abstract
Movement intention detection using electroencephalography (EEG) is a challenging but essential component of brain–computer interfaces (BCIs) for people with motor disabilities. Objective. The goal of this study is to develop a new experimental paradigm to perform asynchronous online detection of movement based on low-frequency time-domain EEG features, concretely on movement-related cortical potentials. The paradigm must be easily transferable to people without any residual upper-limb movement function and the BCI must be independent of upper-limb movement onset measurements and external cues. Approach. In a study with non-disabled participants, we evaluated a novel BCI paradigm to detect self-initiated reach-and-grasp movements. Two experimental conditions were involved. In one condition, participants performed reach-and-grasp movements to a target and simultaneously shifted their gaze towards it. In a control condition, participants solely shifted their gaze towards the target (oculomotor task). The participants freely decided when to initiate the tasks. After eye artefact correction, the EEG signals were time-locked to the saccade onset and the resulting amplitude features were exploited on a hierarchical classification approach to detect movement asynchronously. Main results. With regards to BCI performance, 54.1% (14.4% SD) of the movements were correctly identified, and all participants achieved a performance above chance-level (around 12%). An average of 21.5% (14.1% SD) of the oculomotor tasks were falsely detected as upper-limb movement. In an additional rest condition, 1.7 (1.6 SD) false positives per minute were measured. Through source imaging, movement information was mapped to sensorimotor, posterior parietal and occipital areas. Significance. We present a novel approach for movement detection using EEG signals which does not rely on upper-limb movement onset measurements or on the presentation of external cues. The participants’ behaviour closely matches the natural behaviour during goal-directed reach-and-grasp movements, which also constitutes an advantage with respect to current BCI protocols.
Retraction: The improvement of model predictive control based on three-level three phase inverter (J. Phys.: Conf. Ser.
1601 042032)
Authors: Liu Feng , Dai Jun 
Published: June 2021

This article has been retracted at the request of the authors, who have identified errors in the paper which affect the scientific validity of the work. The authors specifically state "the coefficient of i1T1 should be (1-2k) instead of (2k-1) in the paper. This error is likely to cause conclusions to violate the actual situation."
The authors apologise to the readers, conference organisers and IOP Publishing for these errors.
Retraction published: 15 June 2021
Cross section of the
13C(α,n)16O reaction at low energies
Authors: Ciani G. F. , Csedreki L. , Balibrea-Correa J. , Best A. 
Published: June 2021

Abstract
The
13C(α, n)16O reaction is the main neutron source for the s-process in low mass AGB stars. Although several direct measurements have been performed, no dataset reaches the Gamow window (140-250 keV) due to the the exponential drop of the cross section σ(E) with decreasing energy. The reaction rate becomes so low that the strong cosmic background would become predominant.
In order to measure the
13C(α, n)16O cross section at low energies, a double effort has been performed, namely to suppress the background in the setup and to keep under control the target modification under an intense stable beam provided by the LUNA accelerator (100-200 µA). These measurements were carried out in deep underground laboratories of Laboratori Nazionali del Gran Sasso (LNGS) in the framework of the LUNA experiment. Preliminary results are reported in this contribution.
Analysis and impact of digital modulation techniques on LTE over fibre for 5G systems applications.
Authors: Ojo J S , Dare F O 
Published: June 2021

Abstract
The impact of digital modulation techniques used in Long Term Evolution (LTE) when applied to radio over fibre for fifth-generation systems has been analysed and evaluated in this paper. The analyses are based on the measured BER and the observed eye-diagram with quality factors for the different modulation techniques such as QPSK, 16 QAM, 64 QAM, and 256 QAM. A fibre length between 5 km and 100 km is adopted to showcase the best configuration at a particular length that can support 5G systems. Huge bandwidth and low latency with high spectral efficiency are needed to accommodate 5G applications in areas of critical surgery, home automation, smart transportation, security, and smart cities via IoT among others. Recent researches are focusing on a synergy between the wireless systems and optical network systems to enhance the transmission of RF signals from a central location to a separate unit of the radio element known as the remote radio head (radio over fibre). This technology merges the optical networks and microwaves to provide a possible solution to increase channel capacity, mobility, and reduced the cost of the access network for customers’ comfort. The whole system link is simulated using a commercial optical simulator Optisystem 17.
Basin-wide water demand estimation using RGB color detection of built-up area from satellite imagery
Authors: Lee W K , Syed Yusoff S I 
Published: June 2021

Abstract
The unavailability of as-built drawings and population data in primarily rural east central Java, Indonesia, presents a challenge to effectively estimate the total demand of a proposed large-scale retrofit water supply scheme. A simple RGB color detection method is employed to analyse satellite imageries extracted from Google Earth. The applicable range of RGB spectrum for typical rooftops is ascertained based on image inspection and the candidate areas identified are filtered, smoothened and manually cleaned-up to produce the total built-up area by pixel calibration. Water demand is then estimated based on assumed population equivalent per standard residential unit and consumption rate. The preliminary estimate is further corroborated with the most recent census and population growth rate. Result show that the approach taken is a cost-effective and efficient way for large-scale areal approximation.
Estimation of cloud attenuation over some coastal cities for satellite space links in South Africa
Authors: Olurotimi E O 
Published: June 2021

Abstract
One of the vital constraints on satellite space link systems operating at higher frequencies is attenuation due to clouds. This paper presents a 5-year estimation of cloud attenuation in the millimeter-wave propagation over two coastal cities in the Republic of South Africa. The results show that some salient features of clouds observed were monthly and location dependent. The observed average cloud value ranges between 16% and 55.6%, the relative humidity recorded between 65.4% and 84.2%, while the rainfall amount is between 5.43 and 79.66 mm over the study locations. The specific attenuation coefficient and cloud attenuation increases as the frequency increases over the studied locations. Furthermore, about 1 dB and above was observed at frequencies from 60 GHz and above. The study reveals the impact of liquid water content (LWC) in the clouds, which has a more significant effect on radio signals. The differences in the attenuation observed may be due to the impact of LWC and other salient features observed over the locations.
The Relationship between Ball Speed and Shooting Accuracy during Field Hockey Hit
Authors: Manaf Muhammad Irhami Abdul , Mohamad Nur Ikhwan , Malek Nor Fazila Abd , Jahizi Ahmad Aqil Mohamad , Nadzalan Ali Md 
Published: June 2021

Abstract
There are numerous studies conducted on fundamental skills in field hockey especially drag flick but there is lack of study did on hit or drive skill despite of there were so many beginner and amateur players that required enhancement in this crucial skill. The purpose of this study was to investigate the relationship between ball speed, accuracy, and years of involvement during field hockey hit performance among student recreational players. Fourteen male players were recruited among university students (n=14; Weight = 65.71 ± 7.85 kg, Height = 168.29 ± 3.97 cm; BMI = 23.14 ± 2.41 kg/m2). The participants were required to perform a best single hit skill to determine their ball speed through Kinovea software and the accuracy by the designated score. Then, the data has been analysed through Pearson correlation using the Statistical Package for Social Sciences (SPSS) 21. The Pearson correlation indicated that there is no significant difference for between ball speed and accuracy (r = .024, p = 936) and years of involvement and accuracy (r = .250. p = 389). However, there was a strong and positive correlation between years of involvement and ball speed (r = .672, p =.008). Findings of the current study suggest that the ball speed and accuracy can be increase both at the same time vice versa during hit skill and years of involvement in this sports can be a contributing factor in skill performance.
Comparison of Muscle Activation between Traditional, Clap and Power Push Up Among Trained Men
Authors: Nadzalan Ali Md , Mohd Latif Azane Azran , Hamdan Ahmad Syahir , Yen Lee Ernie Leong , Tan Kevin , Mohamad Jahizi Ahmad Aqil , Pratama Rivan Sagitha 
Published: June 2021

Abstract
This study was conducted to compare the muscle activation during traditional, clap and power push up among trained men. A total of thirty trained men that are physically active and have at least one year experienced in fitness training and having good techniques in push up exercises were recruited as study participants. Participants were required to perform all three types of push up in a randomised order to avoid bias in the exercise sequence. Electromyogram was used to detect the muscle activites of pectoralis major, triceps brachii and anterior deltoids. Muscle activation was reported as percentage of the maximum voluntary contraction value. The results showed that the muscle activation was highest during the clap push up followed by the power push up and traditional push up. As a conclusion, increasing the difficulty by applying plyometric technique during push up give a significant impact in terms of muscle activation in which is believed to be affect the muscle strength and size in long term.
Relationship between Squat Mobility with Snatch and Clean & Jerk Technique
Authors: Mohamad Nur Ikhwan , Alali Ahmad Alhussin , Malek Nor Fazila Abd , Nadzalan Ali Md 
Published: June 2021

Abstract
The purpose of this study is to find if the mobility of the body effect on the Olympic lifting technique performing. Participants of this study involved 22 males and 22 females students Faculty of Sport Science and Coaching aged 20-24 years old. Participants were instructed to perform 3 repetitions of overhead squat mobility performance first, using only their own bodyweight without any equipment at all. Finished with that, participants were then instructed to performed 3 repetitions of snatch technical performance and proceed to the clean and jerk technical performance using the custom-made plastic pipe bar or 20-kg Olympic bar without plate. Result showed that all students had ‘Good” quality of mobility required for the technical performance of snatch, clean and jerk, however practical test indicated a mastery or quality of the technical performance for the snatch was just considered as ‘Fair’ for the male, with the female students scores dip into the ‘Poor’ level of performance. For both genders, all students have a poor technical performance quality for the clean and jerk exercise.
Investigation of Suspended Sediment Samplers: A Review
Authors: Ansari E , Akhtar M N , Bakar E A , Hawary A F , Alhady S S N 
Published: June 2021

Abstract
The flow of rivers and streams carries many particles like sand and silts due to erosion phenomenon which are commonly termed as sediments. Sediments transported along the water flow distributes into either bed load or suspended load. The heavier particles settle down the river bed and form the bed load. While the lighter particles gets suspended along the surface of the water body and are termed as suspended load. The change in sediment concentration affects the hydromorphology of rivers to a great extent. The current study focusses on the measurement of the suspended sediment and reviews the various suspended sediment samplers based on different technical parameters such as working principle, accuracy and specifications. Different mechanical samplers such as bottle and trap samplers, pump samplers; electronic samplers such as Acoustic backscatter profiling sensors (ABS), etc. and optical samplers such as Optical backscatter point sensor (OBS), Optical Laser diffraction point sensors (LISST) and many more sensors such as impact sensors, nuclear sensors and conductivity sensors are reported and compared in this review.
Teaching Approach using Microsoft Teams: Case Study on Satisfaction versus Barriers in Online Learning Environment
Authors: Ismail Sarerusaenye , Ismail Shahrinaz 
Published: June 2021

Abstract
The current pandemic due to Covid-19 has affected most industries including education services. All universities in Malaysia were instructed to close during the first Movement Control Order (MCO), however the classes were still going on in some of the universities. Most of the student’s learning time during this period has been added to the time that most of them already spent at home since the semester began without explicit face-to-face (FTF) instruction from lecturers. Meanwhile, lecturers are scrambling to adapt with the new situation and prepare suitable contents for an online learning platform. This study investigates the problems and challenges that emerged when using online platform, focusing on Microsoft Teams application (Microsoft Teams), and proposes a model of online teaching for theoretical courses in university. The constructive online survey is chosen as the methodology and data collected from 154 undergraduate students are analysed using a technique of quantitative analysis. The results are discussed and at the end, this study proposes a teaching online course via Microsoft Teams application model that is suitable based on successful outputs.
Reliability Analysis on Water Pumps in Water Supply System in Johor
Authors: Alshaari A H , Nor M E 
Published: June 2021

Abstract
The utilization of water pumps in supplying water facilities to consumer should be given priority in terms of operating performance and availability. In light of that, reliability assessments on water pumps were carried out through Mean Time Between Failure (MTBF), Mean Time to Repair (MTTR) and availability. Then, the water pumps’ brands were compared using Mean Cumulative Function (MCF) plot and suggestion strategies through Failure Modes, Effects and Criticality Analysis (FMECA) approach were conducted. There were two types of old and new water pumps which are raw water pump (RWP) and treated water pump (TWP). The name of the brand of old and new RWP and TWP are Brand A, Brand C, and Brand B. Throughout the study, the finding shows that old RWP and new TWP are the most reliable water pumps based on the computation. Besides, Brand A and Brand C were the best brands among others water pumps’ brand by comparing the performance using the MCF plot. Lastly, the suitable strategies suggested to be focused on predictive maintenance, preventive maintenance and corrective maintenance in handling the maintenance.
STRUCTURAL AND ELECTRONIC PROPERTIES OF NBPT INHIBITOR ATTACHED TO UREASE
Authors: Azman Muhammad Harith Daniel , Sin Ang Lee , Zuber Sharifah Zati Hanani Syed , Yaakob Mohd Hafiz , Ghani Zaidi Ab 
Published: June 2021

Abstract
In this study, the structural and electronic properties of the N-(n-Butyl) Thiophosphoric Triamide (NBPT) inhibitor, in the form of monoamidothiophosphoric acid (MATP), as attached to urease enzyme, has been investigated. These include the electron density, molecular orbitals involved in the interactions, and the whole system’s charge distributions. The difference between the interaction of urease-NBPT and urease-urea was conducted throughout this study. This comparison was crucial to prove the NBPT inhibitor’s mechanism to slow down urea’s hydrolysis in the soil solution. The quantum mechanical calculations were performed at the level theory B3LYP/6-31G(d,p). The urease-NBPT complex has higher interaction energy than the urease-urea complex, in which the interaction energy is –1.6787 eV. The urease-NBPT complex has a lower molecular electronic energy gap than the urease-urea complex, at 0.9527 eV. The graphical representation of HOMO, LUMO, and electrostatic potential maps indicates that the NBPT inhibitor can create favourable interaction with the atoms at urease’s active site.