bluuebunny/crossref_metadata_2025 huggingface dataset:
Priority issues and key findings from evaluation of disposal records for a legacy radioactive waste site
Authors: Payne Timothy E , Shatwell Jonathan , Comarmond M Josick
Published: April 2021

This paper reports on a detailed investigation into the disposal procedures and records from the operational period (1960–1968) of the Little Forest Legacy Site (LFLS) in eastern Australia. The aims of the paper are firstly, to highlight the priority issues which are relevant to the radiological assessment of the LFLS, and secondly, to present key lessons that may help to guide future investigations of the records at similar sites. Particular effort was put into assessing the various types of relevant documents and the relationships between them. A specific objective of this work was to evaluate an inventory of the wastes which was reported shortly after the time of disposals. A major finding of the study is that the original actinide inventory for LFLS relied solely on estimates from a limited number of specific records known as ‘Scrap Disposal Reports’ (SDRs). For example, the estimated amount of plutonium disposed at the LFLS was based on only seven SDR records. Given that there are approximately 50000 buried items, it is possible that other Pu-contaminated items could make a significant additional contribution to the amount of Pu present at the site. For some waste components (e.g. beryllium) the documentation shows that rough estimates of disposal quantities were made, based on the number of disposed Be-contaminated items in each trench. The use of such approximations casts some doubt on the accuracy of the previous inventory of wastes at the site. In addition, the early summaries of radionuclide disposals, which categorized radionuclides into groups according to their radiological hazard, contained significant underestimates of the radionuclide inventory in the most hazardous category (referred to at the time as ‘Group I’ radionuclides). This was mainly due to the omission of the Pu (which had been recorded on the SDRs) from the Group I inventory, but was also in part because the Group I radionuclide content of disposed sludge drums (from a wastewater treatment plant) was not taken into account for most of the disposal period. Establishing the disposal history and radionuclide inventory at legacy sites is an important pre-requisite to evaluating their radiological impact and developing management options. The detailed investigation of the LFLS records shows the importance of understanding the operational practices of the period and the derivation of the original inventories. These insights should help guide future efforts to better understand disposal histories and inventories at LFLS and elsewhere.
Adaptive sparse denoising and periodicity weighted spectrum separation for compound bearing fault diagnosis
Authors: Meng Jing , Wang Hui , Zhao Liye , Yan Ruqiang
Published: April 2021

The compound fault diagnosis of rolling bearings has become a hot topic. In this study, a novel method based on adaptive sparse denoising (ASD) combined with periodicity weighted spectrum separation (PWSS) is proposed to diagnose compound faults in rolling bearings. Specifically, ASD reveals fault types and PWSS separates compound faults. First, ASD determines regularization parameters adaptively using the proposed compound frequency multi D-norm, thereby denoising the raw vibration signal and revealing fault types. Then, PWSS constructs the time-frequency spectrum (TFS) and uses the fault periodicity from ASD to determine the time occurrence positions of the repetitive impulses. With this time occurrence position information, a weight matrix is constructed to reweight the TFS. Finally, through the reweighted TFS, PWSS extracts and separates repetitive impulses from compound faults. The performance of the proposed method is validated in both simulation and experimental studies. The results demonstrate that the proposed method can successfully diagnose and separate the compound faults.
Linear phase delay detection method for optical voltage transformer based on S-wave plate
Authors: Xie Nan , Zhu Defeng , Xu Qifeng , Tan Qiao
Published: April 2021

To achieve linear measurement of electro-optic phase delay and improve the accuracy and measurement range of the optical voltage transducer (OVT), this paper proposes a linear phase delay detection method for an optical voltage transformer based on a strip S-wave plate. Using the strip S-wave plate, the phase delay can be directly converted into the displacement of the dark stripe of the strip spot, and the displacement is located by the dual-quadrant detector. Using the Jones matrix, we confirm the linear relationship between the position of the dark stripe and the phase delay, and propose a positioning method and error compensation scheme of the dark stripe and set up an experimental system to verify its performance. The experimental results show that the OVT realizes the measurement of the electro-optic phase delay; the measuring range of the phase delay is up to ±40°, and the measurement error is less than 0.5%.
Tightly-bound trion and bandgap engineering via γ-ray irradiation in the monolayer transition metal dichalcogenide WSe2
Authors: Wu Xiongli , Zheng Xuejun , Zhang Guangbiao , Chen Xinnan , Ding Jianwen
Published: April 2021

After γ-ray irradiation treatment, a monolayer tungsten diselenide could be transitioned into an n-doped semiconductor due to the anion vacancies created by the radiation. Transmission electron microscope studies showed clear chemical modulation with atomically sharp interface. Change in the lattice vibrational modes induced by passivation of oxygen is captured by Raman spectroscopy. The frequency shifts in both in-plane and out-of-plane modes are dependent linearly on the oxidation content. We observe a negative trion, which is a neutral exciton bound with an electron, in the photoluminescence spectra. The binding energy of this trion is estimated to be ∼90 meV, making it a tightly bound exciton. The first-principles calculation suggests that an increase in the anion vacancy population is generally accompanied by a transition from a direct gap material to an indirect one. This opens up a new venue to engineer the electronic properties of transition metal dichalcogenides by using irradiation.
MOF derived double-carbon layers boosted the lithium/sodium storage performance of SnO2 nanoparticles
Authors: Zhu Shaoqing , Huang Aoming , Wang Qian , Xu Ye
Published: April 2021

Tin oxide (SnO2) was considered as a promising alternative to commonly used graphite anode in energy storage devices thanks to its superior specific capacity. However, its electrochemical property was severely limited due to the inherent poor conductivity and drastic volume variation during the charging/discharging process. To overcome this disadvantage, we grew Sn-MOF directly on graphene oxide (GO) layers to synthesize a double carbon conductive network-encapsulated SnO2 nanoparticles (SnO2/C/rGO) via a facile solvothermal method. During the process, Sn-MOF skeleton transformed into porous carbon shells, in which nanosized SnO2 particles (~8nm) were embedded, while GO template was reduced to highly conductive rGO layer tightly wrapping the SnO2/C particles. This double-carbon structure endowed SnO2/C/rGO anode with enhanced specific capacity and rate property both in lithium ion batteries (LIB) and sodium ion batteries (SIB). The SnO2/C/rGO anode showed a highly reversible specific capacity of 1038.3 mAh g−1 at 100 mA g−1, and maintained a stable capacity of 720.2 mAh g−1 (70.1%) under 500 mA g−1 after 150 cycles in LIBs. Similarly, highly reversible capacity of 350.7 mAh g−1 (81.1%) under 100 mA g−1 after 150 cycles was also achieved in SIBs. This work provided a promising strategy in improving the electrochemical properties of SnO2 nanoparticles (NPs), as well as other potential anode materials suffering from huge volume change and poor conductivity.
Heart rate variability in patients with cirrhosis: a systematic review and meta-analysis
Authors: Oyelade Tope , Canciani Gabriele , Carbone Gabriele , Alqahtani Jaber S , Moore Kevin , Mani Ali R
Published: April 2021

Background. Cirrhosis is associated with abnormal autonomic function and regulation of cardiac rhythm. Measurement of heart rate variability (HRV) provides an accurate and non-invasive measurement of autonomic function as well as liver disease severity currently calculated using the MELD, UKELD, or Child–Pugh scores. This review assesses the methods employed for the measurement of HRV, and evaluates the alteration of HRV indices in cirrhosis, as well as their value in prognosis. Method. We undertook a systematic review using Medline, Embase and Pubmed databases in July 2020. Data were extracted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias of the included studies was assessed by a modified version of the Newcastle–Ottawa Scale. The descriptive studies were analysed and the standardized mean differences of HRV indices were pooled. Results. Of the 247 studies generated from our search, 14 studies were included. One of the 14 studies was excluded from meta-analysis because it reported only the median of HRV indices. The studies included have a low risk of bias and include 583 patients with cirrhosis and 349 healthy controls. The HRV time and frequency domains were significantly lower in cirrhotic patients. Between-studies heterogeneity was high in most of the pooled studies (P < 0.05). Further, HRV indices predict survival independent of the severity of liver disease as assessed by MELD. Conclusion. HRV is decreased in patients with cirrhosis compared with healthy matched controls. HRV correlated with severity of liver disease and independently predicted survival. There was considerable variation in the methods used for HRV analysis, and this impedes interpretation and clinical applicability. Based on the data analysed, the standard deviation of inter-beat intervals (SDNN) and SDNN corrected for basal heart rate (cSDNN) are the most suitable indices for prognosis in patients with cirrhosis.
Investigation of the edge ion-to-electron temperature ratio in the J-TEXT tokamak
Authors: Liu Hai , Xu Kangzhong , Xu Yuhong , Chen Zhipeng , Cheng Jun , Liu Haifeng , Wang Xianqu , Huang Jie , Zhang Xin , Shao Junren , Xiao Chijin , Tang Changjian
Published: April 2021

The ion (T
i) and electron (T
e) temperatures at the last closed flux surface (LCFS) during density scanning discharges and in the scrape-off layer (SOL) with a constant plasma density have been measured in the J-TEXT tokamak using a retarding field analyzer and four-tip Langmuir probe, respectively. Both the LCFS T
i and T
e are found to reduce with increasing central line-averaged density (

n
ˉ

e

). The temperature ratio (τ = T
i/T
e) is about 2 for a low

n
¯

e

(1.5 → 2.5 × 1019 m−3), decays in a moderate

n
ˉ

e

(2.5 → 3.5 × 1019 m−3) and tends to unity at a high

n
ˉ

e

(3.5 → 4.2 × 1019 m−3). This suggests that the ions and electrons at the LCFS (even in the SOL) are thermally decoupled at low or moderate

n
ˉ

e

and tend to full thermal coupling in the high-density plasmas. In addition, both T
i and T
e decrease with the radius and T
e falls more steeply than T
i due to faster parallel energy loss of electrons in the SOL. In contrast, τ rises with the radius, which indicates that the ions and electrons are much more thermally decoupled in the deeper SOL.
Photon redistribution of two-terminal perovskite/Si tandem solar cells induced by the optical coupling layer for higher power conversion efficiency
Authors: Liu Chenbo , Xi He , Yan Honghua , Yang Haifeng , Chen Dazheng , Dong Hang , Zhu Weidong , Zhang Jincheng , Zhang Chunfu , Hao Yue
Published: April 2021

The tandem structure is promising to break the Shockley–Queisser limit of single-junction solar cells. Optical management is essential in two-terminal (2T) tandem devices to equalize the current of each sub-cell and enhance the performance. In this work, the photon redistribution effect caused by the optical coupling layer (OCL) and its impact on 2T perovskite/Si tandem solar cells are systematically investigated. We modulate the overall optical field distribution to balance the current of the two sub-cells by structural modulation. The introduction of an OCL affects the photon distribution in the 2T tandem device, which disturbs the original current match and complicates the optical management. In addition to the antireflection function, the photon redistribution effect due to the coupling effects exists for each type of OCL. Various materials (LiF, MgF2, Al2O3 and ZnO) are employed as OCLs and compared. It is shown that they influence the device performance to different degrees. Compared to LiF and MgF2, the influence of the 2T tandem device on short-circuit current density is more significant when Al2O3 and ZnO act as OCLs. By investigating the optical mechanism and then improving the optical management, an optimized device performance can be achieved. We believe that it is necessary to consider the coupling effect in the structural design of 2T tandem solar cells.
Fatigue behavior of REBCO coated conductors under through-thickness tensile stress
Authors: Muto Shogo , Fujita Shinji , Sato Hiroki , Akashi Kazuya , Iijima Yasuhiro , Daibo Masanori
Published: April 2021

Fujikura Ltd has developed production techniques of REBa2Cu3O
X
(REBCO, RE = rare earth) coated conductors (CCs) using large-area ion-beam-assisted-deposition and hot-wall type pulsed-laser-deposition. We have provided high-performance REBCO CCs with long length and high homogeneity of critical current. The CCs are required to maintain their superconducting properties under mechanical stresses for a long-term. Therefore, it is important to evaluate the fatigue properties of the CCs. Although there are many investigations on cyclic tensile fatigue in the longitudinal direction of the CCs, few studies on fatigue properties in the through-thickness direction have been reported. In the case of the through-thickness stress, i.e. delamination stress, the stress is applied to the REBCO ceramic layer without substrate reinforcement, static fatigue fracture may occur by subcritical crack growth peculiar to ceramics. In this work, we carried out dynamic fatigue tests under delamination stresses at room temperature (RT) and liquid nitrogen (LN2) temperature 77 K to determine the fatigue coefficient N characterizing the static fatigue. As a result, we found that the N-value was relatively low (N ∼ 20) at RT, while the N-value was extremely high (N ∼ 150) at LN2 temperature. This result shows that the crack growth of the REBCO layer under the through-thickness tensile stress is extremely slow at low temperatures as well as that reported for bulk ceramics such as SiO2 glass. Therefore, it is expected that the static fatigue in the through-thickness direction of REBCO CC hardly occurs at low temperatures.
Multiplicity dependence in hadroproduction of heavy flavours
Authors: Siddikov Marat , Schmidt Iván
Published: April 2021

In this proceeding we analyze possible mechanisms of quarkonia and open-heavy flavor meson production. We study in detail the contributions of the leading twist two-pomeron fusion and higher twist corrections due to three-pomeron fusion. We show that the latter mechanism is significant for charm production at small transverse momenta. We demonstrate that recent data on the multiplicity dependence of the cross-sections might be naturally explained, both for open-heavy flavor mesons and quarkonia, if the three-pomeron contributions are taken into account.
Lighting of a monochromatic scatterer with virtual gain
Authors: Ali Rfaqat
Published: April 2021

In this work, we discuss the scattering features of a dipolar particle made of large refractive index material by employing the concept of virtual gain and virtual loss. The virtual gain and loss can be achieved in a lossless passive nanostructure by shaping the temporal waveform of incident signals in the complex frequency plane. We show that an appropriate tuning of excitation time of the impinging field allows to capture and release the electromagnetic energy on-demand for an arbitrary time scale in a lossless nanosphere. Thus, the nanosphere obliges to emit monochromatic magnetic light which can be tuned throughout the whole visible spectrum by varying the size of the nanosphere. This proposal may find fruitful applications in lab-on-a-chip technologies and the realization of monochromatic sectoral multipole light source with a large quality factor at nanoscale level.
Heat transfer analysis of MHD rotating flow of Fe3O4 nanoparticles through a stretchable surface
Authors: Shahzad Faisal , Jamshed Wasim , Sajid Tanveer , Nisar Kottakkaran Sooppy , Eid Mohamed R
Published: April 2021

The flow of a magnetite-H2O nanofluid has been considered among two rotating surfaces, assuming porosity in the upper plate. Furthermore, the lower surface is considered to move with variable speed to induce the forced convection. Centripetal as well as Coriolis forces impacting on the rotating fluid are likewise taken into account. Adequate conversions are employed for the transformation of the governing partial-differential equations into a group of non-dimensional ordinary-differential formulas. Numerical solution of the converted expressions is gained by means of the shooting technique. It is theoretically found that the nanofluid has less skin friction and advanced heat transport rate when compared with the base fluid. The effect of rotation causes the drag force to elevate and reduces the heat transport rate. Streamlines are portrayed to reveal the impact of injection/suction.
Neutrons in the classically forbidden region in neutron-rich nucleus 68Ca *
Authors: Zhu Shiwen , Zhang Ying
Published: April 2021

Neutrons tunneling to the classically forbidden (CF) region in the neutron-rich nucleus

are investigated in the Skyrme Hartree-Fock (HF) and Hartree-Fock-Bogoliubov (HFB) models. The definition of the CF region is examined in the HF model by using different single-particle potentials for the bound states. In the HFB model, the weakly bound and continuum states could also contribute to the neutrons in the CF region due to the pairing correlation. Their asymptotic wave functions are carefully calculated by the Green’s function method.
Type-I ELM mitigation by continuous lithium granule gravitational injection into the upper tungsten divertor in EAST
Authors: Sun Z. , Qian Y.Z. , Maingi R. , Wang Y.F. , Wang Y.M. , Nagy A. , Tritz K. , Lunsford R. , Gilson E. , Zuo G.Z. , Xu W. , Huang M. , Meng X.C. , Mansfield D.K. , Zang Q. , Zhu X. , Lin X. , Liu H.Q. , Duan Y.M. , Zhang L. , Lyu B. , Liu Y. , Wang L. , Bortolon A. , Xu G.S. , Gong X.Z. , Hu J.S. , the EAST team
Published: April 2021

Large edge-localized modes (ELMs) were mitigated by gravitational injection of lithium granules into the upper X-point region of the experimental advanced superconducting tokamak (EAST) device with tungsten plasma-facing components. The maximum ELM size was reduced by ∼70% in high β
N H-mode plasmas. Large ELM stabilization was sustained for up to about 40 energy confinement times, with constant core radiated power and no evidence of high-Z or low-Z impurity accumulation. The lithium granules injection reduced the edge plasma pedestal density and temperature and their gradients, due to increased edge radiation and reduced recycling from the plasma-facing components. Ideal stability calculations using the ELITE code indicate that the stabilization of large ELMs correlates with improved stability of intermediate-n peeling-ballooning modes, due to reduced edge current resulting from the profile changes. The pedestal pressure reduction was partially offset by a core density increase, which resulted in a modest ∼7% drop in core stored energy and normalized energy confinement time. We surmise that the remnant small ELMs are triggered by the penetration of multiple Li granules just past the separatrix, similar to small ELMs triggered by deuterium pellet Futatani et al (2014 Nucl. Fusion
54 073008). This study extends previous ELM elimination with Li powder injection Maingi et al (2018 Nucl. Fusion
58 024003) in EAST because (1) use of small, dust-like powder and the related potential health hazards were eliminated, and (2) use of macroscopic granules should be more applicable to future devices, due to deeper penetration than dust particles, e.g. inside the separatrix with velocities ∼10 m s−1 in EAST.
The Influence of Educational Robotics to Abstraction Skill in High School
Authors: Safrudin F M , Budiyanto C W , Yuana R A
Published: April 2021

The skills that individuals need to face the 21st century is computational thinking or CT. Abstraction is a major element in CT. Abstraction ability is an essential ability for students to have, but there is still little research on this ability, especially in Indonesia. If in a programming language, abstraction is the programmers action to focus on essential aspects to simplify and beautify the use of code. This article aims to determine the effect of robotics on the abstraction ability of students in secondary schools. The research results from the literature review show that robotics can improve student’s abstraction abilities. Besides, learning with robotics makes students more interested in the learning process. Educators have started to develop robotics to incorporate it into a variety of subjects. Integration of science, technology, engineering and mathematics disciplines or so-called STEM. It takes teachers who can pursue careers in the STEM field. Besides, STEM learning with robotics requires teachers to be able to explore various abilities, one of which is the abstraction ability of students. With this ability, students are expected to be able to simplify complex problems so that they are easier to solve. Future research is expected to discuss more on this topic.
Implementation of adaptive learning at higher education institutions by means of Moodle LMS
Authors: Morze N , Varchenko-Trotsenko L , Terletska T , Smyrnova-Trybulska E
Published: April 2021

E-learning courses have become popular means of delivering knowledge to students in higher education institutions. Most participants of learning process note that they benefit from the possibility to gain knowledge regardless of time, location and device they use. Among other advantages possibility to return to learnt material several times, divide material into parts, consume information through different types of educational materials (video, infographics, presentations, text, quizzes etc.) are mentioned. At the same time most of the surveyed students chose that they lack personalization both of materials and studying process, limited in terms of fulfillment and would like to have a choice of the level of study. The educational trend that is able to put into practice the above mentioned requirements is blended learning as it has a range of advantages such as usability, consideration of individual abilities, additional materials introduction, activities monitoring. Although it combines offline and online learning, effectiveness of e-learning courses designed for its implementation play a crucial role. To make a learning process correspondent to the students’ needs adaptive learning can be introduced in higher education institutions. Adaptive learning is a methodology that allows to identify level of students’ knowledge and their learning styles and transform materials, tasks and ways of their delivery according to the needs of learning process participants. LMS Moodle offers different solutions for adaptive learning. They provide administrators and teachers with tools to vary all stages of a learning process starting with delivery of information and ending with assessment.
Numerical analysis of Dyakonov surface-wave propagation at the interface of anisotropic and gyrotropic media
Authors: Zakharchenko M V , Glinskii G F
Published: April 2021

The propagation of Dyakonov surface waves was numerically investigated for the interfaces of two biaxial anisotropic media. Variation of the propagation direction changes the field energy localization from one of the partnering media to another. It is possible to find a specific propagation direction, which is characterized by the strongest energy localization in the boundary plane. This direction corresponds to the central angle of the angular existence domain. On the other hand, variation of the components of the media permittivity tensor, including the introduction of gyrotropy, changes the possible propagation directions, which is a potential way to control surface eigenmodes.
Characteristic emission from quantum dot-like intersection nodes of dislocations in GaN
Authors: Shapenkov S V , Vyvenko O F , Schmidt G , Bertram F , Metzner S , Veit P , Christen J
Published: April 2021

Freshly introduced a-screw dislocations in gallium nitride are an effective source of ultraviolet radiation, characterized by intense emission of narrow luminescence doublet lines in the spectral range of 3.1-3.2 eV. Furthermore, an additional narrow spectral line with an energy of 3.3 eV has been found at the points of intersection of such dislocations, where extended dislocation nodes were formed. In this communication, we report on the spectral properties of the characteristic luminescence of such nodes, which were obtained for the (0001) gallium nitride samples with dislocations introduced by nanoindentation. The spectral position of the dislocation-related luminescence doublet experiences a redshift with increasing distance from the indentation site. It follows the spectral shift of the excitonic near-bandgap emission, associated with stress relaxation. The luminescence of the intersection points exhibits a similar tendency. At certain local positions, its doublet fine structure is observed, which has a spectral linewidth of the order of or even less than that of the exciton. In this case, the spectral splitting between components of the doublet varies irregularly depending on the position of the exciton (i.e., on the mechanical stress). We see a clear indication of quantum dot-like emission. The fine structure of the luminescence of the intersection points can be easily explained by the energy dependence of emission on their size, as well as on their density, in particular, by the formation of paired nodes, which were previously observed in experiments in a transmission electron microscope.
Raman spectra of polyethylene glycol/cellulose acetate butyrate biopolymer blend
Authors: Marlina D , Novita M , Anwar M T , Kusumo H , Sato H
Published: April 2021

In order to investigate their crystalline structure conformations, several ratio combinations of polyethelene glycol (PEG)/cellulose acetate butyrate (CAB) were studied by Raman spectroscopy. PEG/CAB spectral features due to the composition dependence revealed the gradual transformation from crystalline PEG-like structure to the amorphous CAB-like structure as increasing the ratio of CAB. Bands appeared in the C-H stretching area of 3000– 2700 cm−1 and C-H bending area of 1500–1400 cm−1 clearly exposed the transition of the PEG to the CAB-spectral features with the transition point at about PEG/CAB (30/70). Band at 1737 cm−1 in the C=O stretching area of 1800–1650 cm−1 described the existence of a very weak hydrogen bond arise between PEG and CAB. In the C-O-C area of 1000–800 cm−1, drastic spectral change suggested that the hydrogen bond interaction takes place in the back bone of PEG.
Bacteriocin antimicrobial isolation in fish soy sauce
Authors: Darmadi N M , Edi D G S , Suryani S A M P
Published: April 2021

Fish sauce can be made from fermented fish. In fermentation plays a role Lactic Acid Bacteria (LAB). The role of lactic acid bacteria has a preservative effect because it can produce compounds that can inhibit the growth of various microbes. Besides lactic acid bacteria produce bacteriocin which also function as antimicrobials. The purpose of this study was to be able to isolate bacteriocin from fish sauce with SDS-PAGE electrophoresis. The study was conducted at the Laboratory of Agricultural Biotechnology Udayana University, Denpasar with a Descriptive Method. The research was carried out in sequence, namely, isolating lactic acid bacteria from fish sauce, Growing Lactic Acid Bacteria on Poor Nutrient Media so that its growth is depressed, because with life stressed Lactic Acid Bacteria can remove Bacteriocin as an Antimicrobial agent. With SDS-Page you will see separate proteins according to their weight, which are specific bands. The protein band which ranges from 17.0 kDa - 17.5 kDa is bacteriocin
Augmented reality: Physics on wave and vibration
Authors: Aji S D , Setyowati T , Jumina S , Hudha M N
Published: April 2021

Augmented reality (AR) is a technology that can be used in the classroom. This study aims to create an AR application and pilot the AR application in the vibrations and waves learning. Furthermore, to see if there are differences in the learning interest and physics learning outcomes by using the AR application in the learning process. The research method used to develop this application is by adapting the 4D Thiagarajan model (Define, Design, Develop, and Disseminate). The result shows there are differences in physics learning outcomes and learning interests of students studying physics using AR. AR and the use of media can be a solution for learning physics in the future.
Digital performance assessment: Measure a pharmacy physics laboratory’s skill
Authors: Dhina M A , Hadisoebroto G , Setiawati I E , Undang G , Masluh M , Mubaroq S R
Published: April 2021

This research is motivated by the importance of skill assessment in pharmacy physics laboratory learning. In general, laboratory skills assessments do not have a specific standard for each assessment. When students perform their performance and skills in doing practicum, they are not well observed and measured. An alternative assessment that can measure a pharmacy physics laboratory’s skill is to use a performance assessment. This study aims to design a digital performance assessment application that can be used to assess student laboratory skills. The development of a digital performance assessment application uses the Waterfall Model Software Development Life Cycle (SDLC) approach, which consists of the main stages of needs analysis, system and software design, system implementation and testing, and maintenance. The digital performance assessment design generally consists of an assessment instrument database and a user interface. Lecturers, as experts, are tasked with making assessment instruments. Meanwhile, the user interface is used by laboratory assistants/instructors to provide skill scores during student practicum. This application is then integrated with the existing web-based electronic module (e-mulsi). In the end, students can see the overall practicum score. The design of a digital performance assessment application is an alternative in a learning assessment platform that is more interesting, actual, and able to present real-time information on practicum learning in the laboratory. Policymakers are expected to consider integrating the use of these applications into a practical learning curriculum.
Transmission elimination of lymphatic filariasis using spatial autocorrelation
Authors: Surjati E , Wiwoho B S
Published: April 2021

At present, spatial analysis has been used on epidemiology. Spatial analysis was used to determine the environmental risk that influence to transmission of Filariasis. The aim of the study was to identify, at industrial area, the environment determinant that are associated with Filariasis cases in Pekalongan City. The geocoding method was applied on the prevalence of cases to determine the pattern of spatial. Spatial autocorrelation was used to determine the effect of the environment on filariasis transmission. The kernel method was used to determine the density of filariasis cases. Based on the spatial analysis, the statistical values associated with the correlation between the risk of filariasis transmission and environmental factors were obtained. The correlation value of the influence of the environment on the transmission of Filariasis was statistically significant, this coefficient is 0.312. The value of R indicates that the spatial pattern of filariasis cases forms a cluster pattern. The Moran’s index calculation obtained a positive spatial autocorrelation value of 0.44 with z-score is 16.05 and P-value is 0.00. Spatial autocorrelation was useful to determining the level of risk transmission of filariasis in Pekalongan City which may help to adopt effective control strategies in filariasis eradication programs in Pekalongan City.
Learning mathematics through media scales of lamps from used goods
Authors: Mutiarawati A , Nurhayati S , Marini A , Sumantri M S
Published: April 2021

This study aims to determine the learning of mathematics through light scales media from used goods. Students’ understanding of weight comparison is still experiencing difficulties. Students often mistakenly distinguish heavy objects from light objects. Teachers have tried to make improvements through learning methods, but only 20% of student learning outcomes have been completed. Therefore, researchers conduct action research studies in the form of treatment for learning media applications. The research subjects were 30 first grade students. Data collection techniques in this study are through observation, tests, and documentation. The results of the study prove that the use of lamp scales media of used goods in mathematics learning that is in the initial conditions, 24 students have not reached skills, but in the first cycle, the number of students who have not reached mastery decreased to 15 students and in the second cycle all students have reached completeness. This study concludes that the use of media scales lamps from secondhand goods can develop mathematical learning understanding, especially in the theory of weight comparison.
Realistic mathematics education on teaching functions to develop algebraic thinking skills
Authors: Hajizah M N , Wijayanti D A , Darhim D
Published: April 2021

This study discusses how the notion of a function can be developed for high school students through the use various contexts that are close to students’ daily life or make sense to them. The Realistic Mathematics Education approach provides the framework that guides the discussions. The concept of function has become one of the basic ideas in modern mathematics that underlies almost all disciplines. But it proved to be one of the most difficult concepts in learning mathematics. The concept of function is often taught without connecting to everyday context. Formal mathematical symbolism of concept such as f(x) introduced prematurely to students which can lead to learning obstacle about functions. The study provides mathematics educators a hypothetical learning trajectory as a platform which facilitates a Realistic Mathematics Education approach to teaching function especially to develop algebraic thinking skills.
Influence of contextual-metacognitive on Self-Regulatory Strategies students in math IV
Authors: Nanang N , Purnamasari I
Published: April 2021

The problem in this study is the low Self-Regulatory Strategies (SRS) of students in Mathematics IV. The purpose of this study is to determine the differences in SRS between students who get a contextual approach with a metacognitive strategy (PKM), contextual approach (PKT), and conventional approach (PKV). This research is an experiment. The subjects in this study were students of Civil Engineering STT Garut semester 4 of 2018 which consisted of three classes (groups). The experimental group-1 was given PKM, the experimental group-2 was given PKT, and the control group was given PKV. The instrument used was a SRS scale based on a Likert scale. Data analysis was performed with ANOVA test. The main results of this study are students who get PKM and PKT significantly better SRS than students who study with PKV. Based on these results, the researcher proposes: (1) the PKM and PKT approaches should continue to be developed and used as an alternative choice for lecturers in Mathematics IV daily lectures and (2) the application of the PKM and PKT approaches becomes input material for policy makers to develop intelligence potential college student.
Mathematical fitting model and analysis in describing Covid-19 viruses outbreak in Indonesia
Authors: Ilahi F , Ibrahim M A , Gojali D , Akmaliyah A , Mashudi D
Published: April 2021

The outbreak of novel coronavirus at the end of 2019 (covid-19) has become a global concern due to its fast transmission from human-to-human. It is first time discovered in Wuhan, Hubei Province in China. In this research, the author tries to construct epidemiological model that consist of six subpopulations such as susceptible (S), exposed (E), infected (I), isolated (Q), recovered (R), and dead (D) population. Those compartments will be analyzed to get basic reproduction number (R0). The data used in this research is secondary data that obtained from the recent study and various news report related to the covid-19 outbreak. Fitting method will be carried out to describe the virus outbreak and see the trend of the future condition based on the real observation data and the mathematical function that has been determined. The expected result of this research is that the mathematical fitting model and its analysis helping the epidemiologist and health practitioner to determine the right treatment to stop the outbreak so that the society could be back to virgin population.
Mathematical communication skills of students through GeoGebra-assisted ELPSA approach
Authors: Maryono I , Rodiah S , Syaf A H
Published: April 2021

The purpose of this study was to see the development of students’ mathematical communication skills between those who obtained the ELPSA learning model assisted by GeoGebra and those who obtained the conventional learning model (direct-instruction). This study uses a quasi-experimental method. The results showed that the achievement and improvement of mathematical communication skills of students who obtained the ELPSA learning model assisted by GeoGebra better than those who obtained the direct-instruction model. The GeoGebra-assisted ELPSA learning model can be used as an alternative in developing mathematical communication skills, especially in the transformation geometry material in secondary schools.
Game-based learning for the mastery of HOTS in prospective physics teachers in digital electronics courses
Authors: Dewantara D , Misbah M , Haryandi S , Mahtari S
Published: April 2021

This study aims to describe the mastery of HOTS of prospective physics teachers in digital electronics courses after implementing game-based learning. The type of research is a quantitative descriptive study. The number of research subjects consisted of 50 students. Data were collected using a test of learning outcomes about digital circuits in the cognitive domains. The data were analyzed to categorize the students’ high-level thinking skills. The data processed were displayed in the form of diagrams and graphs. The data were also equipped with a student response questionnaire. The results of the analysis showed that 46% of the HOTS in students were categorized in “good” category; 28% in “very good” category; a small proportion of others were categorised as “quite good” and “less good”. The HOTS of prospective physics teachers was already sufficient with an average of 70.25. Student responses were deemed in the “good” category. Therefore, it can be concluded that the mastery of HOTS in prospective physics teachers in digital electronics courses after implementing game-based learning is categorized as high. Thus, it is concluded that the mastery of HOTS in prospective physics teacher candidates in digital electronics courses can be further enhanced and trained by applying game-based learning.
Physics module based on STEM problem based learning on newton’s motion law material for senior high school
Authors: Fathurohman A , Susiloningsih E , Arianti A
Published: April 2021

This research aims to produce senior high school physics module based on STEM Problem Based Learning on Newton’s Motion Law Material that is valid and practical. This is a development research using a design model of ADDIE that modified with Tessmer’s formative evaluation method. Tessmer’s formative evaluation stages in this study include self evaluation, expert review, one-to-one and small groups. Data were collected through interviews, expert testing and questionnaires at the expert review stage. The one-to-one and small group stages and field tests were conducted at SHS Number 1 Banyuasin, South Sumatra. The results of the expert review stage obtained the final score of material validation 1 (very feasible or very valid), design validation 0.91 (very feasible or very valid) and language validation 0.95 (very feasible or very valid). Based on the results showed this research produced senior high school module based on STEM Problem Based Learning on Newton’s Motion Law Material. It is recommended that this module can be used as an alternative teaching for Newton’s motion law material.
Differential equations: Solving the oscillation system
Authors: Sujito S , Liliasari L , Suhandi A
Published: April 2021

The purpose of this research is to perform modeling and simulation to solve differential equations in cases of physical phenomena. The physical system studied is simple harmonic motion. The method used is the method of problem solving using computer software. The simulation uses the Matlab program by applying the Euler method. The result obtained is to distinguish the oscillator graph without any external forces with any forces. This solution helps students solve problems using computer software in giving physical meaning. Therefore, students must be trained and guided to have the ability to think to make it easier to solve problems with the help of computers.
Development of an Atwood aircraft practicum tool based on automatic timers to explain Newton’s second law
Authors: Malik A , Utami N F , Rizaldi M F , Sarah S , Nursetia S , Mauli T , Rochman C , Mulhayatiah D
Published: April 2021

The aim of this study was to determine the feasibility of automatic time-lapse-based Atwood aircraft tools to explain Newton’s second law. The method in this research was the experimental method. Instrument testing was carried out at mass loads m1 of 0.01 kg, 0.02 kg, 0.03 kg, by using weights m2 of 0.1 kg at a distance 60 cm and force variations of 0,5 N, 0,6 N and 1 N. The results of the measurement and analysis of the data obtained acceleration in theory Newton’s second law, namely each for mass variants and successive forces is 4.864 m/s2, 4.102 m/s2, 3.414 m/s2, 2.069 m/s2, 2.581 m/s2 and 4.102 m/s2. The results of the acceleration calculation are based on an automatic time interval 4.220 m/s2, 3.826 m/s2, 2.985 m/s2, 1.697 m/s2, 2.415 m/s2 and 3.826 m/s2. The smallest error data is 6.39% and the biggest error is 18%. The results of these measurements indicate the measurement is still accurate because the error percentage is less than 20%.
Physical problem in interpreting classical energy of soliton of sine Gordon equation
Authors: Prayitno T B , Budi E , Sunaryo S , Fahdiran R
Published: April 2021

The classical energy of soliton of sine Gordon equation was evaluated by using the Hamiltonian density. We classify the condition at which the energy will be either convergent or divergent. For the convergent energy, we also impose the condition at which the energy is real. We justify that there is a satisfied condition to obtain real energy.
Research on Reliability Model Evaluation of Satellite Communication System
Authors: Cai Ruiyan , Du Jingjing , Yang Li , Pan Chengsheng
Published: April 2021

Traditional model evaluation methods such as analytic hierarchy process (AHP) cannot provide specific theoretical basis for the later optimization of satellite communication system. To solve this problem, this paper presents an evaluation algorithm based on the reliability modelling process of satellite communication system. The algorithm combines the subjective analysis and objective data in the process of modelling to obtain the fuzzy quantitative evaluation value of the three links of system definition, mathematical model determination and reliability calculation in the process of modelling, and the final Evaluation result is calculated by using Bayesian theory. The validity and feasibility of the algorithm are verified by an example, and some references are provided for the further optimization of the model.
Pose-guided End-to-end Visual Navigation
Authors: Fang Cuiyun , Zhang Chaofan , Tang Fulin , Wang Fan , Wu Yihong , Liu Yong
Published: April 2021

End-to-end visual navigation based on deep reinforcement learning (DRL) has recently attracted much attention. For most existing navigation methods, a robot moves along only fixed directions (e.g., up, down, left and right) on a grid. Obviously, they are not flexible and efficient, which worsens the navigation performance (i.e., the distance of movement and times of rotation). To address this problem, we propose a novel pose-guided end-to-end visual navigation framework, which is flexible and efficient. In the pose-guided navigation framework, a robot can move along arbitrary directions, which are determined by poses between adjacent objects. Further, to select a proper motion and finally form an optimal path, we propose a DRL based action-selected strategy, where a dynamic action select space on the basis of deep siamese actor-critic network is developed. Besides, to validate the proposed method, we propose a novel pose-guided dataset. Experimental results demonstrate that the proposed method outperforms the state of the arts in both flexibility and efficiency.
Analysis of star structure data transmission mode in sensor network system
Authors: Li Yijie
Published: April 2021

Based on the wide application of sensor networks and data transmission in the network, the star structure of sensor networks is composed by using the basic principle and superior performance of sensor nodes, flexible technology and convenient construction. According to the rules and protocols of sensor networks, the star data transmission process is completed. After a large number of data transmission experiments, good experimental results are obtained, and a large number of experimental data are obtained. And the star data transmission process of sensor network is applied to teaching and scientific research practice.
Signal Detection and Identification in an Optical Camera Communication System in Moving State
Authors: Liu Yuanqin , He Weisong
Published: April 2021

Visible Light Communication (VLC) technology uses light-emitting diodes (LEDs) as a signal transmitting source to simultaneously realize lighting and data communication, and the spectrum resources are abundant. Since the visible light communication system with a photodiode (PD) as the receiver has some weaknesses, such as narrow field of view (FOV), inaccurate alignment in moving state, and inadaptability for indoor communication environments, an optical camera communication (OCC) system based on target detection algorithm is proposed in this paper. The system applies a LED array mounted on a moving AGV (automated guided vehicle) as the signal transmitter and a CCD camera as the receiver to realize data transmission in an outdoor environment. In this paper, a VLC MIMO channel model is constructed to verify that simultaneous communication of multiple LEDs through MIMO channels can effectively reduce bit error rate. The designed OCC system utilizes an image processing algorithm based on target detection to detect and identify light signals, realizing relatively stable and reliable communication in the state of motion. The distance from the signal transmitter to the receiver ranges from 6m to 14m.