bluuebunny/crossref_metadata_2025 huggingface dataset:
Allied health are key to improving health for people with chronic disease: but where are the outcomes and where is the strategy?
Authors: Dennis Sarah , Ball Lauren , Harris Mark , Refshauge Kathryn
Published: November 2021

The global burden of chronic disease has forced health systems to focus on improved care. This has led to improved health outcomes for some populations, but not for all people or for all conditions. The rising prevalence of chronic disease has also significantly increased demands on healthcare systems, with unsustainable costs to funders. To improve health and social outcomes for all people with chronic disease, it is critical to embrace allied health professionals as key members of primary healthcare teams. The recognised efficacy and cost-effectiveness of many allied health interventions suggest that implementation into usual care would result in enhanced outcomes for people accessing healthcare, their families and communities, and for health systems. Our aim is to highlight the current unacceptable lack of allied health integration into primary healthcare teams, and illustrate the potential value of improved and equitable access to allied health professionals for managing chronic conditions and multimorbidity.
Asymmetric transfer and development of temporal-aspectual sentence-final particles in English-Cantonese bilinguals’ L3
Mandarin grammars
Authors: Guo Yanyu , Yuan Boping
Published: November 2021

Aiming to shed new light on the discussion on transfer at initial stages of third language (L3) acquisition and
development at later stages, this article reports on an empirical study of L3 acquisition of Mandarin temporal-aspectual
sentence-final particles (SFPs) le, ne and láizhe by English speaking and English-Cantonese
bilingual learners, at both low and high proficiency levels. Cantonese is typologically and structurally closer to Mandarin than
English is. Our findings show obvious facilitative effects on le by its Cantonese counterpart in
English-Cantonese bilingual learners’ L3 Mandarin, which supports the L3 models that advocate the deterministic role of structural
similarity in the transfer source selection. A transfer asymmetry is observed between the cases of le and
láizhe. No transfer effects are found in the L3 Mandarin data of láizhe, even though it has
an equivalent SFP in Cantonese. This discrepancy is argued to be attributable to input factors and misleading forms. Moreover,
patterns observed over different proficiency levels indicate that the quality and quantity of input and the register property of a
particular SFP can greatly affect initial transfer and later development of L3 acquisition.
Use of essential oil for post-harvest pest control
Authors: Shukla Amritesh Chandra
Published: November 2021

Since past few decades, application of essential oils (EOs) was explored experimentally for the management of postharvest pests and diseases. However, uses of essential oils face a series of problems, including regulatory obstruction to commercialization (such as cost of toxicological and environmental assessments) or the way that efficiency of essential oils toward pests and diseases is not as evident or clear as that seen with the present available forms. This review highlights several issues extending from EOs chemistry to their bioactivity potential. The mechanism of action of EOs is also discussed to provide better understanding about their functions and improve the scope for the establishment of commercial opportunities in the form of natural biocontrol agents/botanical pesticides.
Investigating stability and tunability of quantum dot transport in silicon MOSFETs via the application of electrical stress
Authors: Hillier Joseph , Ibukuro Kouta , Liu Fayong , Husain Khaled Muhammad , Byers James , Nicholas Rutt Harvey , Tomita Isao , Tsuchiya Yoshishige , Saito Shinichi
Published: November 2021

In this work, we experimentally investigate the impact of electrical stress on the tunability of single hole transport properties within a p-type silicon MOSFET at a temperature of T = 2 K. This is achieved by monitoring Coulomb-blockade from three disorder based quantum dots at the channel-oxide interface, which are known to lack tunability as a result of their stochastic origin. Our findings indicate that when applying gate biases between −4 V and −4.6 V, nearby charge trapping enhances Coulomb-blockade leading to a stronger quantum dot confinement that can be reversed to the initial device condition after performing a thermal cycle reset. Re-applying stress then gives rise to a predictable response from reproducible changes in the quantum dot charging characteristics with consistent charging energy increases of up to ≈50% being observed. We reach a threshold above gate biases of −4.6 V, where the performance and stability become reduced due to device degradation occurring as a product of large-scale trap generation. The results not only suggest stress as an effective technique to enhance and reset charging properties but also offer insight on how standard industrial silicon devices can be harnessed for single charge transport applications.
IrCrMnZ (Z = Al, Ga, Si, Ge) Heusler alloys as electrode materials for MgO-based magnetic tunneling junctions: a first-principles study
Authors: Roy Tufan , Tsujikawa Masahito , Shirai Masafumi
Published: November 2021

We study IrCrMnZ (Z = Al, Ga, Si, Ge) systems using first-principles calculations from the perspective of their application as electrode materials of MgO-based magnetic tunnel junctions (MTJs). These materials have highly spin-polarized conduction electrons with a partially occupied Δ1 band, which is important for coherent tunneling in a parallel magnetization configuration. The Curie temperatures of IrCrMnAl and IrCrMnGa are very high (above 1300 K), as predicted from mean-field-approximation. The stability of the ordered phase against various antisite disorders is investigated. We discuss here the effect of ‘spin-orbit-coupling’ on the electronic structure around the Fermi level. Further, we investigate the electronic structure of the IrCrMnZ/MgO heterojunction along the (001) direction. IrCrMnAl/MgO and IrCrMnGa/MgO maintain half-metallicity even at the MgO interface, with no interfacial states at/around the Fermi level in the minority-spin channel. Large majority-spin conductance of IrCrMnAl/MgO/IrCrMnAl and IrCrMnGa/MgO/IrCrMnGa is reported from the calculation of the ballistic spin-transport property for the parallel magnetization configuration. We propose IrCrMnAl/MgO/IrCrMnAl and IrCrMnGa/MgO/IrCrMnGa as promising MTJs with a weaker temperature dependence of tunneling magnetoresistance ratio, owing to their very high Curie temperatures.
Asymptotic formulae for estimating statistical significance in particle physics analyses
Authors: Basso M J
Published: November 2021

Within the framework of likelihood-based statistical tests for particle physics measurements, we derive expressions for estimating the statistical significance of discovery using the asymptotic approximations of Wilks and Wald for four measurement models. These models include arbitrary numbers of signal regions, control regions, and Gaussian constraints. We extend our expressions to use the representative or ‘Asimov’ dataset proposed by Cowan et al such that they are made data-free. While many of the expressions are complicated and often involve solving systems of coupled, multivariate equations, we show these expressions reduce to closed-form results under simplifying assumptions. We also validate the predicted significances using toy-based data in select cases and show the asymptotic formulae to be more computationally efficient than the toy-based approach. Additionally, different parameters within each measurement model are varied in order to understand their effect on the predicted significance.
Strain and electric field tunable photoelectric properties of multilayer Sb2Se3
Authors: Ding Wanxin , Li Longhua
Published: November 2021

Antimony selenide, Sb2Se3, has been attracted widespread attention in photovoltaic applications due to its high absorption coefficient and suitable band gap. However, the influence of uniaxial strain and electric field on the electronic and photovoltaic properties of multilayer Sb2Se3 is still unknown. Here, the quantitative relationship, such as strain-property, electric field-property, as well as thickness-property, is explored via first-principles calculations. Our results demonstrate that the band gap and photovoltaic parameters (J
sc, V
oc, FF and PCE) of multilayer Sb2Se3 are not only affected by the uniaxial strain and electric field, but can also be tuned via the coupling of thickness with strain and electric field. The band-gap of multilayer Sb2Se3 is linear dependent on uniaxial strain and external electric field. We found that the effect of strain on the photovoltaic parameters could be negligible as compared with the effect of thickness. However, the effect of electric field is thickness dependent, 1–2 layer(s) thin films are not affected while the impact of electric field increases with the increasing thickness. The quantitative strain (electric field)-properties relation of multilayer Sb2Se3 suggesting that Sb2Se3 films have a potential application in the field of strain and electric field sensors.
Theoretical study of SnS2 encapsulated in graphene as a promising anode material for K-ion batteries
Authors: Kang Xuxin , Xu Wei , Duan Xiangmei
Published: November 2021

Rechargeable batteries with superior electronic conductivity, large capacity, low diffusion barriers and moderate open circuit voltage have attracted amount attention. Due to abundant resources and safety, as well as the high voltage and energy density, potassium ion batteries (KIBs) could be an ideal alternative to next-generation of rechargeable batteries. Based on the density functional theory calculations, we find that the SnS2 monolayer expands greatly during the potassiumization, which limits its practical application. The construction of graphene/SnS2/graphene (G/SnS2/G) heterojunction effectively prevents SnS2 sheet from deformation, and enhances the electronic conductivity. Moreover, the G/SnS2/G has not only a high theoretical special capacity of 680 mAh g−1, but an ultra-low K diffusion barrier (0.08 eV) and an average open circuit voltage (0.22 V). Our results predict that the G/SnS2/G heterostructure could be used as a promising anode material for KIBs.
Motion in nuclear cardiology imaging: types, artifacts, detection and correction techniques
Authors: Mohammadi Iraj , Castro Filipe , Rahmim Arman , Veloso João
Published: November 2021

In this paper, the authors review the field of motion detection and correction in nuclear cardiology with single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging systems. We start with a brief overview of nuclear cardiology applications and description of SPECT and PET imaging systems, then explaining the different types of motion and their related artefacts. Moreover, we classify and describe various techniques for motion detection and correction, discussing their potential advantages including reference to metrics and tasks, particularly towards improvements in image quality and diagnostic performance. In addition, we emphasize limitations encountered in different motion detection and correction methods that may challenge routine clinical applications and diagnostic performance.
Comprehensive investigation of radiofrequency/analog parameters in a ferroelectric tunnel field-effect transistor
Authors: Saha Rajesh , Goswami Rupam , Bhowmick Brinda , Baishya Srimanta
Published: November 2021

In this paper, the effect of ferroelectric (FE) layer thickness (t
FE), coercive field (E
c), remnant polarization (P
r) and saturation polarization (P
s) on the transfer characteristic is highlighted for a FE tunnel field-effect transistor (Fe-TFET) through a commercial technology computer-aided design simulator. Further, we have reported the radiofrequency (RF)/analog parameters such as transconductance, output conductance, gain, gate capacitance and cut-off frequency for a wide range of FE parameters in a Fe-TFET. An improved RF/analog performance and transfer characteristic are obtained for a low value of t
FE and P
r, whereas these behaviors are degraded at high values of P
s and E
c.
Fundamentals and working mechanisms of artificial muscles with textile application in the loop
Authors: Grellmann Henriette , Lohse Felix M , Kamble Vikram G , Winger Hans , Nocke Andreas , Hickmann Rico , Wießner Sven , Cherif Chokri
Published: November 2021

Natural muscles, that convert chemical energy derived from glucose into mechanical and thermal energy, are capable of performing complex movements. This natural muscle power was the only way to perform mechanical work in a targeted manner for millions of years. In the course of thousands of years of technical development, mankind has succeeded in harnessing various physical and chemical phenomena to drive specific mechanical processes. Wind and water power, steam and combustion engines or electric motors are just a few examples. However, in order to make the diversity and flexibility of natural motion patterns usable for machines, attempts have been made for many years to develop artificial muscles. These man-made smart materials or structures are able to react to environmental conditions by significantly changing their shape or size. For the design of effective artificial muscles that closely resemble the natural original, the usage of textile technology offers great advantages. By means of weaving, individual actuators can be parallelized, which enables the transmission of greater forces. By knitting the maximum stretching performance can be enhanced by combining the intrinsic stretching capacity of the actuators with the structural-geometric stretching capacity of the fabric. Furthermore textile production techniques are well suited for the requirement-specific, individual placement of actuators in order to achieve the optimal geometry for the respective needs in every load case. Ongoing technical development has created fiber based and non-fibrous artificial muscles that are capable of mimicking and even out-performing their biological prodigy. Meanwhile, a large number of partly similar, but also very different functional principles and configurations were developed, each with its own specific characteristics. This paper provides an overview of the relevant and most promising technical approaches for realizing artificial muscles, classifies them to specific material types and explains the mechanisms used as well as the possible textile applications.
Active scour monitoring using ultrasonic time domain reflectometry of buried slender sensors
Authors: Funderburk Morgan L , Tran Jamie , Todd Michael D , Netchaev Anton , Loh Kenneth J
Published: November 2021

Local scour is a growing cause of bridge failure in the United States and around the world. In the next century, the effects of climate changes will make more bridges susceptible to scour failure more than ever before. This study aims to harness the spatially continuous monitoring capabilities of ultrasonic time-domain reflectometry to detect a soil interface for the purposes of scour monitoring. In this study, a long, slender plate is coupled with two flexible piezoelectric devices that propagate Lamb waves along the length of the plate to form the scour sensor. The sensor was tested for sensitivity to external pressure using metal weights and was able to detect the position of the pressure up at a length of up to ∼20 feet. The sensor was tested under simulated scour conditions, being buried in sand at various depths. The results show that the Lamb wave scour sensor is capable of reliably detecting a soil interface at 1 ft intervals. The scour sensor was also able to detect uncompacted soil interfaces, which is important considering the issue of scour hole refill following an extreme event.
Synthesis and rheological characteristics of high viscosity linear polysiloxane carrier fluid-based magnetorheological fluids
Authors: Xie Lei , Choi Young-Tai , Liao Chang-Rong , Zeng Zhi , Wereley Norman M
Published: November 2021

This study addresses the synthesis and field-dependent rheological characteristics of novel magnetorheological fluids (MRFs) using high viscosity linear polysiloxanes (HVLPs) as a carrier fluid. First of all, the components and preparation of novel HVLP-based MRFs (HVLP MRFs) were explained in detail and the microscopic images of each component were taken by using scanning electron microscope (SEM). Four HVLP MRF samples with different particle volume fractions of 10, 15, 20, and 26 vol% in the same HVLP carrier fluid viscosity of 800 Pa·s were synthesized to investigate the particle concentration effect on their field-dependent rheological properties. In order to understand the effect of the carrier fluid viscosity, two more HVLP MRF samples with different HVLP viscosities of 140 and 440 Pa·s in the same particle concentration of 26 vol% were also fabricated. In addition, the temperature effect on HVLP MRFs was studied by using the sample with 26 vol% in particle concentration and 140 Pa·s in HVLP viscosity under different operating temperatures of 25 °C, 40 °C, 55 °C and 70 °C. The flow curve measurements of shear stress versus shear rate in the magnetic fields were conducted by using controlled shear rate (CSR) test method with a commercial parallel-plate type rotational rheometer. From the flow curves, the field-dependent rheological properties of HVLP MRFs including static and dynamic yield stresses and the dynamic range (ratio of field on to field off yield stress) were obtained. These material characteristics were then examined as a function of varying particle concentration, varying carrier fluid viscosity, and varying temperature. A conventional commercial MRF (i.e. Lord MRF-126CD) was adopted for comparison study and its rheological properties under different temperatures were also measured and compared with those of HVLP MRFs. Using HVLP carrier fluids, it was demonstrated that the HVLP MRFs exhibited much greater suspension stability than the conventional commercial MRF.
Tungsten Langmuir probes from JET-with the ITER-Like Wall: Assessment of mechanical properties by nano-indentation
Authors: Spychalski Maciej , Fortuna-Zalesna E , Zdunek Joanna , Rubel Marek , Widdowson Anna , Aleiferis Spyridon , Thomas Beth
Published: November 2021

Tungsten Langmuir probes retrieved from the JET tokamak with the ITER-Like Wall (JET-ILW) after the second ILW campaign were examined by nano-indentation, microscopy and x-ray diffraction in order to determine changes in mechanical properties and phase composition. Not-exposed probe served as a reference material. Two regions were studied: (i) recrystallized region below the tip and, (ii) the lower probe structure, called ‘support structure’. A large difference between the hardness in the tip and the other region has been found: 5 GPa versus 15 GPa, respectively. The measured values of the Young’s modulus in both zones of exposed probe are at the same level of 260 GPa. From the force-displacement curves, it can be concluded that the material in the tip has a smaller range of elastic deformations compared to that characteristic for the support structure. The values obtained for the material in its initial state are consistent with the available literature data for tungsten. With x-ray diffraction and microscopy only tungsten has been detected in the probe tip. It remained clean and free from impurities and undesirable compounds, which could have a negative impact on the probes electrical properties.
A Real Expectation Value of the Time-dependent Non-Hermitian Hamiltonians*
Authors: Kecita F , Bounames A , Maamache M
Published: November 2021

With the aim to solve the time-dependent Schrödinger equation associated to a time-dependent non-Hermitian Hamiltonian, we introduce a unitary transformation that maps the Hamiltonian to a time-independent




-symmetric one. Consequently, the solution of time-dependent Schrödinger equation becomes easily deduced and the evolution preserves the


(
t
)
PT

−inner product, where


(
t
)

is a obtained from the charge conjugation operator



through a time dependent unitary transformation. Moreover, the expectation value of the non-Hermitian Hamiltonian in the


(
t
)
PT

normed states is guaranteed to be real. As an illustration, we present a specific quantum system given by a quantum oscillator with time-dependent mass subjected to a driving linear complex time-dependent potential.
Coupled Schrödinger equations as a model of interchain torsional excitation transport in the DNA model
Authors: Kovaleva Margarita , Manevitch Leonid
Published: November 2021

In this report we consider two weakly coupled Schrödinger equations as a reduced model of interchain energy transport in the DNA double-helix torsional model. We employ a reduction of the Yakushevich-type model that considers the torsional dynamics of the DNA as effective chains of pendula. In previous works, only small amplitude excitations and stationary dynamics were investigated, whereas we focus on the nonstationary dynamics of the double helix. We consider the system to be a model of two weakly interacting DNA strands. Assuming that initially only one of the chains is excited in the form of a breather, we demonstrate the existence of an invariant that allows us to reduce the order of the problem and examine the system of the phase plane. The analysis demonstrates the utility of an analytical tool for predicting the periodic interchain excitation transitions of its localisation on one of the chains. The technique also takes into account the spreading of the excitations over time.
L-band femtosecond fiber laser with Cu2Te-PVA thin film
Authors: Ahmad H , Kahar N H Abdul , Norisham N F , Reduan S A , Bayang L
Published: November 2021

For the first time, this research proposed a copper telluride (Cu2Te)-polyvinyl alcohol thin film as a saturable absorber (SA) in an erbium-doped fiber laser (EDFL) operating in the long-wavelength band (L-band). The nonlinear optical absorption measurement of Cu2Te thin film revealed a saturation intensity of 3.26 kW cm−2 and a modulation depth of 2.7%. Furthermore, the mode-locked pulse was successfully generated by integrating a Cu2Te thin film into the L-band cavity at a threshold pump power of 135.61 mW with a center wavelength and pulse duration of 1565.48 nm and 770 fs, respectively. When observing the output mode-locked pulse, the pump power for the EDFL ranged from 135.61 mW to 201.28 mW, with the fundamental mode having a repetition rate 10.28 MHz. Furthermore, the magnitude of the signal-to-noise ratio was approximately 61.3 dB, indicating that the laser was stable with no significant fluctuations during the stability test. Overall, the findings showed that Cu2Te thin film has an excellent output and a promising candidate for an SA, implying that it could have a lot of potentials in pulsed laser application.
Mechanisms underlying activation of retinal bipolar cells through targeted electrical stimulation: a computational study
Authors: Paknahad Javad , Kosta Pragya , Bouteiller Jean-Marie C , Humayun Mark S , Lazzi Gianluca
Published: November 2021

Objective. Retinal implants have been developed to electrically stimulate healthy retinal neurons in the progressively degenerated retina. Several stimulation approaches have been proposed to improve the visual percept induced in patients with retinal prostheses. We introduce a computational model capable of simulating the effects of electrical stimulation on retinal neurons. Leveraging this computational platform, we delve into the underlying mechanisms influencing the sensitivity of retinal neurons’ response to various stimulus waveforms. Approach. We implemented a model of spiking bipolar cells (BCs) in the magnocellular pathway of the primate retina, diffuse BC subtypes (DB4), and utilized our multiscale admittance method (AM)-NEURON computational platform to characterize the response of BCs to epiretinal electrical stimulation with monophasic, symmetric, and asymmetric biphasic pulses. Main results. Our investigations yielded four notable results: (a) the latency of BCs increases as stimulation pulse duration lengthens; conversely, this latency decreases as the current amplitude increases. (b) Stimulation with a long anodic-first symmetric biphasic pulse (duration > 8 ms) results in a significant decrease in spiking threshold compared to stimulation with similar cathodic-first pulses (from 98.2 to 57.5 µA). (c) The hyperpolarization-activated cyclic nucleotide-gated channel was a prominent contributor to the reduced threshold of BCs in response to long anodic-first stimulus pulses. (d) Finally, extending the study to asymmetric waveforms, our results predict a lower BCs threshold using asymmetric long anodic-first pulses compared to that of asymmetric short cathodic-first stimulation. Significance. This study predicts the effects of several stimulation parameters on spiking BCs response to electrical stimulation. Of importance, our findings shed light on mechanisms underlying the experimental observations from the literature, thus highlighting the capability of the methodology to predict and guide the development of electrical stimulation protocols to generate a desired biological response, thereby constituting an ideal testbed for the development of electroceutical devices.
Assessment of Teachers’ Knowledge about Tuberculosis at Primary School in Balad City
Authors: Hasanain Wafaa S.
Published: November 2021

Tuberculosis (TB) is one of the most common infectious diseases worldwide and continues to be a major public health problem for low and middle-income countries. Undoubtedly, Lack of knowledge about tuberculosis among health care and education workers, as well as if knowledge and practices of tuberculosis among students were generally insufficient causes an increased risk of contracting the disease.

Tuberculosis (TB) is a chronic communicable bacterial disease caused by Mycobacterium tuberculosis. The Latest World Health Organization (WHO) Report shows that there were 9.0 Million new TB cases and 1.5 Million tuberculosis deaths. The Transmission of the TB disease by Mycobacterium tuberculosis (a bacterium of a group that includes the causative agents of tuberculosis). takes place by air in the form of sneeze, talk, cough, spit, etc.
[1,9,11,12,13]

This applied study attempt to identify, assess and analyze teachers’ knowledge about tuberculosis in primary schools. A descriptive design, cross-sectional study was carried out in order to achieve the earlier stated objectives of this study by find out the relationship between teachers’ knowledge and social demographic data (sex, age, academic achievement, ….).

The present study lasted for four months by prepared a questionnaires to assess the level of teachers’ knowledge, and these questionnaire contains many themes, each theme contained a number of questions to evaluate and analyze teachers’ knowledge of tuberculosis by answering a set of questions (as a variables); (mode of transmission, symptoms and signs, diagnostic features of TB, duration of treatment, prevention methods, risk of developing tuberculosis). The research hypothesis also states that (mycobacterium tuberculosis factor) has a direct impact on TB infection, and to achieve this hypothesis, a questionnaire was distributed to a sample with a size of (58) teachers and the method of Multiple Logistic Regression was used for statistical treatment. Finally, the research concluded a set of results and conclusions included in tables by comparing Likelihood-ratio chi-square statistics and classification table of the observed versus predicted responses.
Using Accelerometer Smartphone Sensor and Phyphyox for Friction Experiment in High School
Authors: Ilmi Y F , Susila A B , Iswanto B H
Published: November 2021

Experiments related to friction in schools are mostly done by direct observation, and it becomes more difficult to determine the value of the coefficients of static and kinetic friction due to the low level of accuracy. This study aims to develop a friction coefficient practicum tool using the accelerometer sensor on a smartphone with the Phyphox application. The research was conducted using the 4D Thiagarajan method (Define, Design, Develop, Disseminate). This tool demonstrates experimental friction on an inclined plane with a variety of surface materials (aluminium, wood, glass, acrylic). The results recorded by Phyphox are spreadsheets of object acceleration data per unit time in x, y, and z coordinate graphs. The sliding plane frame is designed using an Arduino microcontroller which can make it easier for students to automatically form inclined plane angles. This tool has been tested by experts with an average score are 85.25% and has been tested on physics teachers with an average score of 82.5% in the good category. This friction coefficient practicum tool is feasible and can help students understand the concept of friction
Unveil Problem Based Learning on Physics Learning: A Literature Review
Authors: Mustika  , Wibowo F C
Published: November 2021

Scientific literacy is one of the benchmarks for the ability of words in the divinity of daily life. This study is about problem-based learning (PBL) on learning physics from aspects of the word, not, and its implementation. The writing of this article uses literature reviews. First of all, the study problem is formulated, then while it is being experienced by existing and relevant researchers to be analyzed. Data collection techniques with electronic journals through google scholar, Scopus, Microsoft academies, Harzing’s Publish or Parish, and crossref. From the results of 20 articles from journals and 3 e-books. Based on the results of the analysis concluded that the Problem Based Learning model is a skill skill, thinking analysis skills, and scientific attitudes. The results of the journal synthesis show that there have been no research results linking the learning-based problem model to the variety of science literacy skills. This becomes a loophole and basis for advanced research and development of e-Module-based learning problems. The thing behind the varied skills of science skills is one of the problems one sign of learning there is a problem, student-centered learning, and learning in a small group.
Algebraic integrability of

PT

-deformed Calogero models
Authors: Correa Francisco , Lechtenfeld Olaf
Published: November 2021

We review some recents developments of the algebraic structures and spectral properties of non-Hermitian deformations of Calogero models. The behavior of such extensions is illustrated by the A
2 trigonometric and the D
3 angular Calogero models. Features like intertwining operators and conserved charges are discussed in terms of Dunkl operators. Hidden symmetries coming from the so-called algebraic integrability for integral values of the coupling are addressed together with a physical regularization of their action on the states by virtue of a

PT

-symmetry deformation.
Solitons in a

PT

-symmetric grating-assisted co-directional coupler
Authors: Jones Hugh , Kulishov Mykola
Published: November 2021

We explore a co-directional coupling arrangement between two waveguides mediated by a PT-symmetric sinusoidal grating characterized by an index-modulation parameter κ and a gain/loss parameter g. We show that the device supports soliton-like solutions for both the

PT

-conserving regime g < κ and the

PT

-broken regime g > κ. In the first case the coupler exhibits a gap in wave-number k and the solitons can be regarded as an extension of a previous solution found for pure index modulation. In the second case the coupler exhibits a gap in frequency ω and the solutions are entirely new.
Benign ghosts in higher-derivative systems
Authors: Smilga Andrei
Published: November 2021

A brief review of the physics of systems including higher derivatives in the Lagrangian is given. All such systems involve ghosts i.e. the spectrum of the Hamiltonian is not bounded from below and the vacuum ground state is absent. Usually this leads to collapse and loss of unitarity. In certain special cases, this does not happen, however: ghosts are benign. This happens, in particular, in exactly solvable higher-derivative theories, but exact solvability seems to be a sufficient but not a necessary condition for the benign nature of the ghosts.

We speculate that the Theory of Everything is a higher-derivative field theory, characterized by the presence of such benign ghosts and defined in a higher-dimensional bulk. Our Universe represents then a classical solution in this theory, having the form of a 3-brane embedded in the bulk.
Fall-to-the-centre as a

PT

symmetry breaking transition
Authors: Sundaram Sriram , Burgess C P , O’Dell Duncan H J
Published: November 2021

The attractive inverse square potential arises in a number of physical problems such as a dipole interacting with a charged wire, the Efimov effect, the Calgero-Sutherland model, near-horizon black hole physics and the optics of Maxwell fisheye lenses. Proper formulation of the inverse-square problem requires specification of a boundary condition (regulator) at the origin representing short-range physics not included in the inverse square potential and this generically breaks the Hamiltonian’s continuous scale invariance in an elementary example of a quantum anomaly. The system’s spectrum qualitatively changes at a critical value of the inverse-square coupling, and we here point out that the transition at this critical potential strength can be regarded as an example of a

PT

symmetry breaking transition. In particular, we use point particle effective field theory (PPEFT), as developed by Burgess et al [1], to characterize the renormalization group (RG) evolution of the boundary coupling under rescalings. While many studies choose boundary conditions to ensure the system is unitary, these RG methods allow us to systematically handle the richer case of nonunitary physics describing a source or sink at the origin (such as is appropriate for the charged wire or black hole applications). From this point of view the RG flow changes character at the critical inverse-square coupling, transitioning from a sub-critical regime with evolution between two real, unitary fixed points (

PT

symmetric phase) to a super-critical regime with imaginary, dissipative fixed points (

PT

symmetry broken phase) that represent perfect-sink and perfect-source boundary conditions, around which the flow executes limit-cycle evolution.
Elasto-thermoviscoplastic finite element analyses of cold upsetting and forging processes of S25C steel with dynamic strain aging considered
Authors: Ji S M , Razali M K , Lee K H , Chung W J , Joun M S
Published: November 2021

A practical methodology is presented to characterize the thermoviscoplastic flow stress at larger strain over the temperature range of cold metal forming using tensile and compression tests. Its importance is emphasized for non-isothermal finite element (FE) analysis of automatic multi-stage cold forging (AMSCF) process where maximum strain and strain rate exceed around 3.0 and 200/s, respectively. The experimental compressive flow stress is first characterized using traditional bilinearC-mmodel with high accuracy. It is employed for describing the closed-form function model to extrapolate the experimental flow stress over the experimentally uncovered ranges of state variables. The strain effect on the flow stress is then improved using the experimental tensile flow stress accurately calculated at large strain and room temperature. A complicated flow behavior of S25C characterized by its dynamic strain aging features is expressed by the presented methodology, which is utilized to analyze the test upsetting and AMSCF processes by the elasto-thermoviscoplastic finite element method for revealing the effects of flow stresses on the process.
Numerical investigation on the effect of second throat diameter on two-throat nozzle ejector
Authors: Jia F T , Yang D Z , Xie J
Published: November 2021

The employment of two-phase ejectors in the CO2 refrigeration systems is widely developed recently. Due to the lack reports on the two-throat nozzle ejectors, the performance of CO2 two-throat nozzle ejector varied with different second throat diameter (D

t
) was numerically investigated under different primary pressures (P

p
). The accuracy of established numerical simulation model was confirmed with the assistance of experimental data summarized in the literature. The simulated results show that the two-throat nozzle ejector performance corresponding to entrainment ratio (Er) is of better stability with relatively bigger D

t
under different working conditions. Next, the axial static pressure corresponding to bigger D

t
is lower than that of smaller one at pre-mixing chamber. And the secondary flow velocity of bigger D

t
is accelerated better as compared to that of smaller one.
Extraction of Bio-oil from Sugarcane Leaves
Authors: Thanigaivelan V , Kishore Kumar T K , Hari Prasad G , Daniel Jeysingh K , Mohit R
Published: November 2021

Bio oil production has become the main substitute for fossil-based fuels, but it should be available as a cost-effective method for its production. Extraction of bio-oil from sugarcane leaf is the motive of this project. We are going to achieve this by grinding the leaves freshly into a liquid form with Sugarcane Juicer that is going to be inoculated with Saccharomyces Cerevisiae (Brewer’s Yeast). The yeast culture was maintained in YPD (Yeast Peptone Dextrose) agar medium for 72 Hours. Once this Yeast grows, it is coagulated with the Sugarcane leaf extract that separates Bioethanol by distillation. Then this Bio-oil can be used in engines. This Bio oil is made because this is cost efficient. It is less pollutive when compared to other gasoline Products. These leaves are mostly thrown out as trash or else it is burnt, so this could be a method of changing those trash into one of the Valuable resources of fuel for Heavy vehicles.
Analysis of disturbance source location of direct drive wind turbine based on energy function
Authors: Zhang Zijie , Cao Na
Published: November 2021

In order to locate the disturbance source quickly and accurately in the wind farm, taking the direct drive wind turbine as an example, using the transient energy method, firstly, the transient energy flow formula is derived according to the mathematical model of each part of the direct drive wind turbine, the energy flow power is obtained by linear fitting, and the position of the disturbance source is judged by the positive and negative energy flow power; then a single machine infinite bus system model with forced oscillation source is built on PSCAD/EMTDC simulation platform for simulation. The results show that the transient energy method can accurately locate the disturbance source of direct drive wind turbine unit.
Research on Photovoltaic power prediction technology Based on Machine Learning
Authors: Li Hongxia , Li Jianlin , Mi Yang
Published: November 2021

In recent years, the photovoltaic power generation has obvious intermittent, randomness and volatility, and high permeability photovoltaic will have a huge impact on the safety and stability of the grid. The prediction of photovoltaic power generation is to improve the quality of photovoltaic grid, optimize grid scheduling, and ensure the basic technology of power grid safety and stability. In order to improve the prediction accuracy of photovoltaic power generation, this article will comprehensively carding and compare from 3 dimensions: photovoltaic power generation and meteorological factor correlation analysis, similar day selection, prediction method based on machine learning, and summarize the advantages and disadvantages of various methods. Further research has been put forward accordingly.
One hundred kilojoules of energy storage in water wire electric explosion deposition energy study
Authors: Liu Simin , Zhang Yongmin , Lu Yong , Zhang Shaojie
Published: November 2021

In this experiment, the electro-explosive deposition energy in water of aluminum-magnesium welding wire model ER5356 at 100 kJ capacitive storage energy was investigated. The loop current and the load discharge voltage during the wire electrical explosion were measured using a self-integrating Roche coil and a capacitive voltage divider, respectively. The physical process of electrical explosion and the energy deposition process were delineated by the measured loop currents and load voltages. The current waveform and load voltage of the electric explosion in water of 1.2 mm-3.0 mm diameter Al-Mg wire at 100 kJ stored energy were measured; the changes of load resistance value, load power and deposition energy of the wire loaded with electric explosion were calculated. The results show that the peak circuit current and peak time point decrease and then increase with increasing diameter, and the minimum value is achieved at 1.6 mm wire diameter; the load voltage and load resistance values gradually decrease with increasing diameter; the load power and total deposited energy of discharge achieve the maximum value at 2.0 mm diameter. At 100 kJ energy storage, there is an optimal range between 1.6 mm and 2.4 mm wire diameter.
Research on Peak Load Shifting Operation Strategy of Small-Scale Mobile Energy Storage Device in Distribution Network
Authors: Chen JianMing , Dai Ruijin , He Yilin , Chen Tiancheng , Chen Weimin
Published: November 2021

This paper studied two methods of using energy storage (ES) to achieve peak load shifting by charging and discharging. In different distribution network transformer power supply areas, the time of peak and valley of load is not identical. The small-scale mobile ES device was commanded to deliver energy at the peak of the power supply area to reduce the supply pressure of the power system by central control units (CCU), and while the load is at the valley, the ES charges and absorbs power to enhance the utilization rate of energy in the system. Currently, the control methods of peak load shifting for ES device (Constant Power Control and Threshold Control) were studied, and the operation results in power system were analyzed with their involvement, which provided the substantial supports for CCU to dispatch. Ultimately, the results showed the methods proposed were feasible and effective by simulation.
Substation-area Backup Protection Scheme for the Failure of 10kV Line Protection Device
Authors: Wang Yuxue , Liu Wei , Jiao Shaolin , Fang Zeya , Li Yiquan , Wen Minghao
Published: November 2021

The research on wide-area backup protection for high-voltage transmission lines has made certain progress in recent years, but there are few reports published on substation-area backup protection for low-voltage 10kV transmission lines. Based on the characteristics of shared information in intelligent substation, a substation-area backup protection scheme to deal with the failure of 10kV line protection device is proposed in this paper. This scheme uses the device self-test information and heartbeat mechanism to monitor the operation status of 10kV line protection devices; to realize the substation-area backup protection for the 10kV transmission lines when any line protection device fails, the protection criterion is constructed by the action results of power directional elements of transformer protections and other 10kV line protections. The proposed scheme can greatly improve the speed of the fault isolation and has low requirements for data demand and synchronization. PSCAD simulation results show that the proposed method is with high correctness and feasibility.
Influence of local shadow on output of photovoltaic array
Authors: Tai Kexin , Mo Chengkai , Hang Chao
Published: November 2021

This paper first deduces the engineering mathematical model of photovoltaic cells, then builds the photovoltaic cell and photovoltaic array model in Matlab/Simulink, and then simulates and compares the output of photovoltaic array under the condition of series and parallel connection, the number of shadows and shadow distribution. Finally, the different effects of shadow in series and parallel and the influence of shadow distribution on the output of photovoltaic array are analyzed.
Short-term load prediction of integrated energy system based on neural network
Authors: Wang Yao , Li Xuxia , Liang Yan , Hu Yingying , Zheng Xiaoming , Deng Jiaojiao
Published: November 2021

Considering the correlation and nonlinear characteristics of multiple types of loads in the integrated energy system, grey relation analysis (GRA) and long short term Memory (LSTM) neural network are selected to establish the short-term load prediction model of the integrated energy system. The model uses GRA method to analyze the coupling between multiple types of loads and the meteorological factors, and then obtains the load forecast results through the LSTM prediction model. Finally, a practical example is given to verify the validity of the model.
Research on Consistency of Transient Response Characteristics of Current Transformers for DC application in DC Engineering
Authors: Deng Xiaopin , Huang Hua , Liu Yong , Wang Xiaozhou , Liu Bin
Published: November 2021

In ultra high voltage(UHV) DC system, the transient characteristics for fault current monitoring of current transformers for DC application (DCCTs) and the consistency of response characteristics when different types of DCCTs are used for differential protection have become important factors affecting the safe and stable operation of DC system. In this paper, transient characteristics of all-fiber DCCTs and shunt DCCTs mainly used in DC system were studied, the main parameters of the transient characteristics including delay time and maximum peak instantaneous error were tested, and the key parameters influencing the response consistency of DCCTs were analyzed. The results show that the maximum peak instantaneous errors of all-fiber DCCTs and shunt DCCTs can meet ±5% limit requirement, meeting the demand for protection application in DC system. The delay time is the main factors affecting the maximum peak instantaneous error of DCCT. The longer the delay time is, the greater the maximum peak instantaneous error is, which may even exceed the limit value of ±5%. If necessary, the delay time of DCCTs participating in differential protection can be compensated. The research results provide a theoretical basis for preventing the malfunction of protection device caused by the inconsistent response characteristics of DCCTs in DC system.
Mechanical Fault Diagnosis of High Voltage Circuit Breaker based on Improved GSO-SVM Algorithm
Authors: Xia Xiaofei , Rao Xiajin , Su Yi , Lu Yufeng , Feng Bo
Published: November 2021

The vibration signal generated by the transmission and impact of mechanical components of circuit breaker has chaotic performances, which is difficult to be analysed by conventional signal processing methods. The phase space reconstruction of vibration signal is worked on, and the signal reconstruction parameters are calculated by mutual information method and Cao algorithm respectively. The vibration signal is reconstructed into a high-dimensional space, and its permutation entropy is calculated as a feature vector. Support vector machine (SVM) is used to identify the failure type of circuit breaker, and PSO improved GSA hybrid algorithm is used to optimize the parameters of SVM so as to obtain high recognition accuracy. The experiment is carried out with the measured vibration signal of the typical operation state of the circuit breaker. The results show that the characteristics of circuit breaker vibration signals can be extracted accurately with the combination of phase space reconstruction and permutation entropy. By using PSO-GSA-SVM, the fault types of circuit breakers can be identified quickly and effectively, and the problems of path distortion, energy leakage and mode overlap of existing diagnosis methods can be solved.