bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multi-modal commutative dynamics in semi-crystalline polymers undergoing multiple shape memory behavior
Authors: Wang Xiaodong , Lu Haibao , Gorbacheva Galina , Hossain Mokarram , Fu Yong Qing 
Published: February 2021

Abstract
Semi-crystalline polymers offer great opportunities for design and tuning of multi-shape memory effect (multi-SME) through their programmable melting transitions. However, coexistence of amorphous and crystalline components as well as their multiple interfaces results in complex cooperative dynamics. In this study, we propose a one-dimensional multi-modal dynamic model to describe the commutative and cooperative dynamics in semi-crystalline shape memory polymers undergoing multi-SME. A three-phase model and Takayanagi principle are firstly applied to study the cooperative dynamics of amorphous/crystalline components and their interfaces. Phase transition theory and modified Avrami theory are used to model the cooperative dynamics of glass and melting transitions, respectively. Commutative dynamics and glass/melting transitions are further investigated to achieve on-demand multi-SME and shape recovery behaviors. Finally, effectiveness of the newly established model was demonstrated to predict triple-SMEs and quadruple-SMEs in semi-crystalline polymers reported in literature, and the theoretically obtained results show good agreements with the experimental ones.
Stable and functional solutions of the Klein-Fock-Gordon equation with nonlinear physical phenomena
Authors: Alam Md Nur , Bonyah Ebenezer , Fayz-Al-Asad Md , Osman M S , Abualnaja Kholod M 
Published: February 2021

Abstract
The present article uses a modified

G
′

G

-expansion method and the generalized Kudryashov method on Klein-Fock-Gordon (KFG) equation and receives some stable and functional solutions. The obtained results are checked by putting backwards into the physical model and are very beneficial over various existing processes. The diverse variety of stable and functional outcomes such as kink-type shape, bright and dark lump shape, bright and dark singular kinky shape, periodic bright and dark lump shape, multiple bright and dark lump shape, the lump with rough wave shape, the rough wave shape and the kinky shape are taken. The above procedure could also be employed to get stable and functional solutions for other integral and fractional nonlinear models in physics, mathematics, and engineering.
Enhancing Direct Exoplanet Spectroscopy with Apodizing and Beam Shaping Optics
Authors: Calvin Benjamin , Jovanovic Nemanja , Ruane Garreth , Pezzato Jacklyn , Colborn Jennah , Echeverri Daniel , Schofield Tobias , Porter Michael , Wallace J. Kent , Delorme Jacques-Robert , Mawet Dimitri 
Published: February 2021

Abstract
Direct exoplanet spectroscopy aims to measure the spectrum of an exoplanet while simultaneously minimizing the light collected from its host star. Isolating the planet light from the starlight improves the signal-to-noise ratio (S/N) per spectral channel when noise due to the star dominates, which may enable new studies of the exoplanet atmosphere with unprecedented detail at high spectral resolution (>30,000). However, the optimal instrument design depends on the flux level from the planet and star compared to the noise due to other sources, such as detector noise and thermal background. Here we present the design, fabrication, and laboratory demonstration of specially-designed optics to improve the S/N in two potential regimes in direct exoplanet spectroscopy with adaptive optics instruments. The first is a pair of beam-shaping lenses that increase the planet signal by improving the coupling efficiency into a single-mode fiber at the known position of the planet. The second is a grayscale apodizer that reduces the diffracted starlight for planets at small angular separations from their host star. The former especially increases S/N when dominated by detector noise or thermal background, while the latter helps reduce stellar noise. We show good agreement between the theoretical and experimental point spread functions in each case and predict the exposure time reduction (∼33%) that each set of optics provides in simulated observations of 51 Eridani b using the Keck Planet Imager and Characterizer instrument at W. M. Keck Observatory.
Programmable quantum processor implemented with superconducting circuit
Authors: Jiang Nian-Quan , Liang Xi , Wang Ming-Feng 
Published: February 2021

Abstract
A quantum processor might execute certain computational tasks exponentially faster than a classical processor. Here, using superconducting quantum circuits we design a powerful universal quantum processor with the structure of symmetric all-to-all capacitive connection. We present the Hamiltonian and use it to demonstrate a full set of qubit operations needed in the programmable universal quantum computations. With the device the unwanted crosstalk and ZZ-type couplings between qubits can be effectively suppressed by tuning gate voltages, and the design allows efficient and high-quality couplings of qubits. Within available technology, the scheme may enable a practical programmable universal quantum computer.
High yield polar direct drive fusion neutron sources at the National Ignition Facility
Authors: Yeamans C.B. , Kemp G.E. , Walters Z.B. , Whitley H.D. , McKenty P.W. , Garcia E.M. , Yang Y. , Craxton R.S. , Blue B.E. 
Published: February 2021

Abstract
Polar direct drive neutron source experiments were performed at the National Ignition Facility showing substantial improvement in total neutron yield and efficiency of conversion of laser energy to fusion output. Plastic capsules 3–4 mm in diameter were filled with 1.5 mg/cc of deuterium–tritium (DT) fuel and imploded with laser beam pointing and defocus designed to compensate for polar asymmetry introduced by the facility beam entrance angles. Radiation-hydrodynamics simulations were employed to optimize the multi-dimensional laser and target parameter space, within facility and target fabrication constraints. Ensembles of 1D simulations tuned to match the outputs of early shots in the series were used to design subsequent shots in the series. This allowed the later shots to be designed based on empirically motivated sensitivities to laser and target input parameters, while eliminating the need to explicitly model phenomena such as hydrodynamic instabilities and nonlinear laser–plasma interactions. One experiment with a 3.0 mm diameter CH capsule produced 13.6 kJ (4.81 × 1015 DT neutrons) from a laser input below the NIF optics damage threshold at 585 kJ, 328 TW. Two experiments with 4.0 mm capsules produced 31.3 and 33.6 kJ of fusion output (1.11 × 1016 and 1.19 × 1016 DT neutrons) with 1.10 MJ, 390 TW and 1.26 MJ, 425 TW of laser input, respectively.
Sum rules for the supersymmetric eight-vertex model
Authors: Brasseur Sandrine , Hagendorf Christian 
Published: February 2021

Abstract
The eight-vertex model on the square lattice with vertex weights a, b, c, d obeying the relation (a
2 + ab)(b
2 + ab) = (c
2 + ab)(d
2 + ab) is considered. Its transfer matrix with L = 2n + 1, n ⩾ 0, vertical lines and periodic boundary conditions along the horizontal direction has the doubly-degenerate eigenvalue Θ
n
= (a + b)2n+1. A basis of the corresponding eigenspace is investigated. Several scalar products involving the basis vectors are computed in terms of a family of polynomials introduced by Rosengren and Zinn-Justin. These scalar products are used to find explicit expressions for particular entries of the vectors. The proofs of these results are based on the generalisation of the eigenvalue problem for Θ
n
to the inhomogeneous eight-vertex model.
Assessment of Geomagnetically Induced Currents in Low Latitude Regions with respect to Severe Geomagnetic Storm over Solar Cycle 24
Authors: Iffah Abd Latiff Zatul , Huzaimy Jusoh Mohamad , Burhanudin Kharismi 
Published: February 2021

Abstract
Space Weather Perturbation – driven Geomagnetically Induced Currents (GIC) can cause the adverse impact to series of ground technological instruments. Power networks are the most affected technological facilities that experience malfunctions due to GIC phenomenon. High latitude regions experience more power network operation flaws due to this natural threat compared to mid latitude and low latitude regions. However different event of solar activities exhibit different space weather perturbations impacts regionally. Therefore, in this study, a thorough analysis of GIC activities during 6 severe geomagnetic storms in low latitude regions over solar cycle 24 based on Time Derivative of Horizontal Component of Geomagnetic Field (dH/dt) analysis are conducted. The results revealed that there is non-uniform latitudinal distribution of averaged dH/dt value in low latitude region and high GIC occurrences are observed during dayside. The correlation analysis between Solar Wind Parameters and GIC activities depicted that solar wind dynamic pressure (Psw) and Solar wind input energy (ε) act as Solar wind driver for the occurrences of GIC in low latitude region.
Behaviour of Geomagnetic storm, horizontal geomagnetic field and solar wind parameters during solar flare and CMEs event.
Authors: Syed Zafar S N A , Hazmin S N , Jusoh M H , Dagang A N , Adzni M A M , Umar R 
Published: February 2021

Abstract
Space weather is driven by solar activities by pulling out the variety of phenomenon such as solar flare and coronal mass ejection (CMEs). It been discovered the CMEs and solar flares have causes disturbance at near-Earth space. This paper is to examined the behaviour of geomagnetic storm, horizontal geomagnetic field and several solar wind parameters during solar flare and CMEs event at minimum of solar cycle of 24. Observational result found that association of strongest solar flare and CMEs have declined the geomagnetic storm until -150nt at 8th September 2017. Following to this, the H component reading also slightly decreased at three magnetometer location respectively. Solar flare and CMEs released the energetic particles that could disturbed the radio communications at the Earth and electronic equipment. Therefore, it was required to study and understanding the solar flare and CMEs event.
Defining different type of CEJ currents based on ground-based geomagnetic data record at Langkawi station, Malaysia
Authors: Rosli N I M , Hamid N S A , Abdullah M , Yoshikawa A 
Published: February 2021

Abstract
A negative decrement in geomagnetic data in equatorial region is not necessarily cause by the well-known counter electrojet, CEJ but it is also can be affected by solar activity such as a solar flare. Relying on this matter, we did a comparison between CEJ and unusual solar flare effect called as SFE* on geomagnetic data before introducing several types of CEJ that can be extracted from EUEL index. This study used ground data from MAGDAS network located in Langkawi (LKW) with 1-minutes resolution during solar cycle 24 and applied EUEL index. From the results, it is crucial to ensure the minimum duration of EUEL depletion is within an hour because less than an hour depletion could be possibly cause by solar activity. Four interval of time that has been introduced in our study composed of several types of CEJ which are morning CEJ, afternoon CEJ and evening CEJ, with additional the controversial CEJ occurrence which is night CEJ. We also successfully demonstrated a rare CEJ occurrence that associated with solar flare effect using EUEL index.
Analysis of a geomagnetic induced current on a three-phase power transformer and power system
Authors: Adiba Zawawi Anis , Fadilah Ab Aziz Nur , Zainal Abidin Abd Kadir Mohd , Hashim Halimatun 
Published: February 2021

Abstract
A geomagnetic induced current (GIC), resulting from adverse space weather, has a low occurrence rate but the potential for high impact events. Such events can disrupt the operation of a power system, especially the power transformer as the current flows in the transmission lines and through the transformer ground points. It is a well-documented fact that a GIC can cause a significant threat to ground-based networks as the induced current can enter into the transmission system through the wye-grounded transformers. This paper presents a simulation of a GIC on an IEEE 9-bus test system under steady-state conditions using PSCAD/EMTDC software. The main focus of this paper is the effects of a GIC on a three-phase power transformer that includes half cycle saturation and reactive power consumption. Based on the simulation results under GIC conditions, the magnitude flux and magnetising current of the power transformer as well as reactive power consumption increase and may lead to power system instability.
Amateur satellite ground station: Troubleshooting and lesson learned
Authors: Ali F Z , Rahim S N M , Jusoh M H 
Published: February 2021

Abstract
Few troubleshooting steps have been taken during the non-operation period of UiTM ground station (UiTMSAT) where some of the main equipment and systems were malfunction. After few resolutions performed, the root cause of the defect was detected. The issue occurred due to the lighting strike that has transferred abundant amount of electricity to the devices in the monitor room. This paper explains the resolution steps that were taken to resolve the issue in the ground station. The maintenance is performed on radio, rotator controller, rotator interface, terminal node controller (TNC) and the software used for the satellite operation. The issues on the radio and rotator devices made some difficulties in using the operation software which are the SatPC and BIRDS operation software. Several attempts have been done and through this, many lessons were learned by the ground station operator. These lessons were shared to other BIRDS members during the ground station workshop at Kyushu Institute of Technology (KYUTECH), Japan.
Zenithal Sky Brightness Measurement at Selangor Observatory
Authors: Ngadiman N F , Shariff N N M , Hamidi Z S 
Published: February 2021

Abstract
The first continuous assessment of night sky brightness (NSB) at Selangor Observatory are presented. The brightness at night sky was monitored over 6 months in 2018, using portable light sensor called the Sky Quality Meter-type USB-Data Logging with a fixed position - pointing towards zenith. From the 179 records of night, the study shows that the average NSB readings at Selangor Observatory is 20.04 ± 0.18 magnitude per square arc second (MPSAS), after excluding the moonlight factor. Meanwhile, during the stable night sky conditions, the most recorded NSB value is 21.1 MPSAS with 0.78 MPSAS range and 21.03 MPSAS in average. Therefore, Selangor Observatory is still a relevant location for the implementation of astronomical work since it has a night sky within Bortle scale Class 4 to 5.
Energy transitions, air quality and health
Authors: Pereira Gavin , Bell Michelle L , Honda Yasushi , Lee Jong-Tae , Morawska Lidia , Jalaludin Bin 
Published: February 2021

Abstract
The way we produce and use energy is transforming. Policy in this area intersects decisions that affect climate change, air quality, and the economy. The exponential increase in use of fossil fuel and nuclear energy has now essentially replaced human and animal energy (McKinney 2019 Curr. Pollut. Rep.
5 394–406; Solomon and Krishna 2011 Energy Policy
39 7422–31). These transitions have contributed to notable gains, such as improvements in mortality rates attributable to improved heating, water quality and transportation (Rayner 2012 Ecological Public Health : Reshaping the Conditions for Good health/Geof Rayner and Tim Lang (Abingdon, Oxon: Earthscan); Rosen 2015 A History of Public Health (Jhu Press); Pain 2017 Nature
551 S134–7; Cutler and Miller 2005 Demography
42 1–22). However, such transitions have also been accompanied by health detriments. Improvements in transportation and occupational efficiencies have promoted lifestyle transitions that have contributed to the chronic disease epidemic (Heath 2009 Am. J. Lifestyle Med.
3 27S–31S). Certain energy-related accidents and waste products have been long-established as carcinogenic (Guizard et al 2001 J. Epidemiol. Community Health
55 469; Cardis and Hatch 2011 Clin. Oncol.
23 251–60) and potential precursors to genetic mutations (Beir 1990 Health Effects of Exposure to Low Levels of Ionizing Radiation (Washington, DC: National Academy of Sciences); Desouky
et al 2015 J. Radiat. Res. Appl. Sci.
8 247–54). Moreover, air pollution emissions are increasingly becoming recognised as a major contributor the global burden of disease, particularly cardiovascular and respiratory mortality (Cohen et al 2017 Lancet
389 1907–18). Although renewable energies can be perceived as ‘clean’, the shift to renewables has been relatively more recent and consequently, less is known about associated health impacts. The life course of renewable energy begins with the process of manufacturing renewable technologies, includes the means of transportation for the distribution and collection of these technologies as well as the disposal of their waste products and subsequent contamination. All of these stages have potential to involve direct chemical exposures through the groundwater, soil or air; and have potential to affect health through indirect pathways. A relatively understudied area, and the topic of this Focus Issue on Energy Transitions, Air Quality and Health, is the relevance of energy transitions and their associated environmental factors in a contemporary setting, how such factors affect health now, and will affect health in future.
Tail-behavior roadmap for sharp restart
Authors: Eliazar Iddo , Reuveni Shlomi 
Published: February 2021

Abstract
Many tasks are accomplished via random processes. The completion time of such a task can be profoundly affected by restart: the occasional resetting of the task’s underlying random process. Consequently, determining when restart will impede or expedite task completion is a subject of major importance. In recent years researchers explored this subject extensively, with main focus set on average behavior, i.e. on mean completion times. On the one hand, the mean approach asserts the centrality of ‘sharp restart’—resetting with deterministic (fixed) timers. On the other hand, a significant drawback of the mean approach is that it provides no insight regarding tail behavior, i.e. the occurrence likelihood of extreme completion times. Addressing sharp restart, and shifting the focus from means to extremes, this paper establishes a comprehensive tail-behavior analysis of completion times. Employing the reliability-engineering notion of hazard rate, the analysis yields a set of universal results that determine—from a tail-behavior perspective—when sharp restart will impede or expedite task completion. The universal results are formulated in terms of simple and explicit hazard-rate criteria. With these novel results at hand, universal average-&-tail classification manuals for sharp restart are devised. The manuals specify when the average and tail behaviors are in accord, and when they are in dis-accord. Notably, the manuals pinpoint general scenarios in which—rather counter-intuitively—sharp restart has an opposite effect on average behavior and on tail behavior: decreasing mean completion times while dramatically increasing the likelihood of extreme completion times; and, conversely, increasing mean completion times while dramatically decreasing the likelihood of extreme completion times.
A Comparative Study on the Readiness Parameters of Highway Construction Projects
Authors: Radzi A R , Rahman R A , Doh S I , Esa M 
Published: February 2021

Abstract
Successful highway projects could help contribute to a country’s economic development and growth. One of the factors that cause delays in highway projects is starting too early (i.e., premature start), and assessing the readiness of the project before construction could prevent it from happening. However, different types of highway projects can have various causes of delay. Therefore, having inappropriate readiness parameters can impair the process of assessing construction readiness. This study aims to compare the construction readiness parameters (CRPs) between different types of highway projects. To achieve that objective, questionnaire survey data from 105 industry practitioners with highway construction working experiences is analyzed using the analysis of variance (ANOVA), descriptive statistics, and mean score ranking technique. The results reveal 32 CRPs that are critical for both highway and expressway projects. Also, there are 6 CRPs that are only critical for highway projects. This study contributes to the current body of knowledge by illustrating any discrepancies of the readiness parameters between types of highway projects. The lessons from this study could help the industry to justify the usage of the parameters for assessing their highway projects in preventing premature starts.
Strategies for virtual teams in construction: Easiness-effectiveness analysis
Authors: Manea A A , Radzi A R , Rahman R A , Haron A T 
Published: February 2021

Abstract
Technology has contributed to the development of the construction sector. Scientific discoveries have resulted in the cooperation of a group of people from different geographic locations who depend on communication technologies (i.e., a virtual team). Virtual teams use advanced technology to fix communication issues and are considered as a practical, productive, and creative team concept. Thus, it is evident that the virtual team also needs to concern about improving construction efficiency. This study aims to define the strategies that maximize the effectiveness of virtual teams in the construction industry in Malaysia. To achieve the objective, a questionnaire survey was conducted with industry practitioners from the Malaysian construction industry. Data of 112 respondents were collected and analyzed. The results reveal that seven strategies are perceived by industry practitioners to be both the most effective and easiest in enhancing virtual teams. Conversely, ten strategies are either the most effective or easiest to be implemented. This research adds to the body of knowledge is in expanding the understanding of virtual teams in the construction industry in Malaysia, which could support industry practitioners in the decision-making process for improving virtual teams. The findings of this research would help increase the efficiency of the project teams in the construction industry.
Research on Voltage Control Method of Distributed Photovoltaic Distribution Network Considering Electric Vehicle Charging
Authors: Wang Zhi , Yu Lianghui , Ji Tongjun , Zeng Yuzhu , Ji Yongchao 
Published: February 2021

Abstract
A large number of distributed photovoltaic grid connected to the grid is the main reason for voltage overrun of low-voltage distribution network. Therefore, this paper proposes a voltage control method using electric vehicle (EV) and photovoltaic inverter. Firstly, the distributed control of photovoltaic inverter is adopted. The voltage is regulated by controlling the active power output and reactive power output of the photovoltaic inverter, and the utilization rate of each photovoltaic inverter is the same. If the voltage is not within the safety threshold or the spare capacity of the PV inverter is insufficient, the charging and discharging power control of the electric vehicle will be carried out, and the charging and discharging rate will be controlled according to the consistency target of the electric vehicle power utilization and the SOC local information. The low-voltage distribution system is built in Matlab/Simulink. The simulation results show that the proposed control method is feasible and effective, and the voltage overrun problem in this area is effectively solved.