bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of a single Gaussian shape of spectral line measured with low-dispersion spectrometer by using machine learning
Authors: Kin F. , Nakano T. , Oyama N. , Terakado A. , Wakatsuki T. , Narita E.
Published: May 2021

We have developed a denoising autoencoder based neural network (NN) method to determine a spectral line intensity with an uncertainty lower than the uncertainty determined by fitting the spectral line. The NN method processes the measured raw spectral line shape, providing a single Gaussian shape based on the training dataset, which consists of synthetically prepared Doppler shift and broadening free spectral lines in the present work. It is found that the uncertainty reduction level significantly depends on the training dataset. Limitations originating from the training dataset are also discussed.
Transitional flaw size sensitivity of amorphous silica nanostructures analyzed by ReaxFF/SiO based molecular dynamics
Authors: Park John , Kirane Kedar
Published: May 2021

This paper presents an investigation aimed at understanding the flaw size sensitivity in amorphous silica nanostructures. The investigation is carried out in LAMMPS via reactive molecular dynamics analyses by employing ReaxFF–SiO, a bond order-based force field. First, a validated procedure is developed to build the amorphous silica nanostructures via a melt, quench, and equilibration process. This procedure is seen to correctly reproduce the molecular structure as well as mechanical properties of silica. The best agreement to experimental data is obtained by using non-periodic boundary conditions with the isothermal–isobaric ensemble. The validated model is then used to analyze crack propagation in amorphous silica samples with varying flaw sizes subjected to mode I tensile fracture. The analyses reveal a marked transition from flaw sensitive to insensitive behavior with decreasing flaw size. The transition flaw size is found to be 20–25 Å. Fracture propagation is found to be accompanied by the formation of several single atom thick strands near the crack tip, previously reported as “stress fibers.” This is proposed as a viable mechanism causing blunting of an initially sharp crack, analogous to blunting of a macroscale crack by an inelastic damage zone. The nanoscale fracture process zone estimated by probing near crack tip stresses is found to nearly equal the transition flaw size, providing an explanation for the transitional behavior. A semi-empirical, transitional flaw size effect law rooted in quasibrittle fracture mechanics is derived based on asymptotic matching and is found to capture well the nanoscale transitional behavior.
Ferromagnetism in 2D α-Fe2O3 nanosheets
Authors: Mohapatra Jeotikanta , Ramos A. , Elkins J. , Beatty J. , Xing M. , Singh Dylan , La Plante Erika Callagon , Ping Liu J.
Published: May 2021

In this report, hematene (2D α-Fe2O3 nanosheets) with an exceptionally high coercivity of up to 7.5 kOe has been synthesized via a soft-chemical exfoliation process. The high coercivity correlates with the surface magnetic anisotropy that originates from enhanced uncompensated spin canting as a result of the 2D morphology. This observation is different from the behavior of the bulk counterpart that exhibits collinear antiferromagnetic ordering with no net magnetization at low temperatures. In addition, our study shows a suppression of the Morin transition in 2D nanosheets, which further confirms that the surface spins deviate strongly from the collinear antiferromagnetic ordering. We also observed a spin-glass-like transition with a rapid increase in saturation magnetization and a decrease in anisotropy in the ultra-thin α-Fe2O3 nanosheets at temperatures below 48 K. The spin-glass behavior is correlated with the observed exchange bias and the magnetic field dependence of spin-glass freezing temperature.
Impact of dimensionality and confinement on reaction dynamics and thermodynamics within 1D and 2D nanostructures
Authors: McTaggart Matt , Li Xia , Groves Michael , Shah Vishva , Jugroot Manish , Malardier-Jugroot Cecile
Published: May 2021

Confinement has been shown to contribute to the dynamics of small molecules within nanoscale hydrophobic or hydrophilic cavities. Enclosure within a confined space can also influence energy transfer pathways, such as the enhancement of fluorescence over thermal relaxation. In this paper, the effect of confinement on the thermodynamic properties and reaction kinetics of small hydrophobic molecules confined in a soft polymeric template is detailed. A quasi-elastic neutron scattering experiment identified a substantial decrease in translational diffusion of pyrrole after solubilization within a hydrophobic cavity. This decrease in mobility is due to pyrrole’s closer packing and increased density under confinement vs the bulk liquid. The decreased mobility and increased density explain the spontaneous polymerization reaction of pyrrole observed within the cavity. The precise characterization of the polymerization kinetics under confinement found that the reaction is independent of pyrrole concentration, consistent with the close packing density. Kinetic data also show that confinement dimensionality finds a thermodynamic expression in the transition state entropy. The dynamics and kinetics experiments reported here offer rare empirical insight into the important influence that cavity geometry places on the reactions they host.
On the rate of energy deposition by an ion ring velocity beam
Authors: Omelchenko Yuri A. , Rudakov Leonid , Ng Jonathan , Crabtree Chris , Ganguli Gurudas
Published: May 2021

Using a novel three-dimensional electromagnetic hybrid code, XHYPERS, we simulate the generation of lower hybrid oscillations in a magnetized plasma by a heavy ion beam with a ring-shaped velocity distribution over much longer periods of time compared to previous simulations. We introduce a phenomenological (effective) electron damping to represent the induced scattering of lower-hybrid waves to whistlers and the loss of energy through whistler propagation out of the turbulent region. We demonstrate the effective electron damping to be a crucial factor in increasing the efficiency of energy deposition by an ion ring velocity beam into plasma turbulence and investigate the efficiency of beam energy extraction as a function of the electron damping rate and beam to plasma ion mass ratio.
Analysis of two-level systems and mechanical loss in amorphous ZrO2-doped Ta2O5 by non-cage-breaking and cage-breaking transitions
Authors: Jiang Jun , Mishkin Alec S. , Prasai Kiran , Zhang Rui , Yazback Maher , Bassiri Riccardo , Fejer Martin M. , Cheng Hai-Ping
Published: May 2021

The energy landscape of ZrO2-doped amorphous Ta2O5 is explored in this work. With models corresponding to experimental concentrations of 50% Zr and 50% Ta cations, we search for, gather, and analyze two-level systems (TLSs) from molecular dynamic simulations. The mechanical loss function is calculated for each TLS individually. The results show that TLS with low asymmetry and large elastic coupling constants contribute the most to mechanical loss. We identify these as “bad actors.” The higher barriers relate to the mechanical loss at higher temperatures. The concept of the oxygen cage that describes the local structural environment surrounding a metal ion is introduced. The existence of a drastic change in local environment, or a cage-breaking process, enables us to understand the double peaks present in the asymmetry distribution and provides a pictorial interpretation to distinguish two types of TLS. Quantitatively, a cage-breaking event is related to at least one large distance change in an atom–atom pair, and non-cage-breaking transitions have only small rearrangements. The majority of TLSs are cage-breaking transitions, but non-cage-breaking TLS transitions show higher average mechanical loss in ZrO2-doped Ta2O5. By decomposing the contributions to mechanical loss, we find that the low temperature loss peak near 40 K mainly comes from non-cage-breaking TLS transitions and the second loss peak near 120 K originates from cage-breaking TLS transitions. This finding is important for understanding the interplay between the atomic structure of TLS and mechanical loss.
High-temperature phase transitions in dense germanium
Authors: Kelsall Liam C. , Peña-Alvarez Miriam , Martinez-Canales Miguel , Binns Jack , Pickard Chris J. , Dalladay-Simpson Philip , Howie Ross T. , Gregoryanz Eugene
Published: May 2021

Through a series of high-pressure x-ray diffraction experiments combined with in situ laser heating, we explore the pressure–temperature phase diagram of germanium (Ge) at pressures up to 110 GPa and temperatures exceeding 3000 K. In the pressure range of 64–90 GPa, we observe orthorhombic Ge-IV transforming above 1500 K to a previously unobserved high-temperature phase, which we denote as Ge-VIII. This high-temperature phase is characterized by a tetragonal crystal structure, space group I4/mmm. Density functional theory simulations confirm that Ge-IV becomes unstable at high temperatures and that Ge-VIII is highly competitive and dynamically stable at these conditions. The existence of Ge-VIII has profound implications for the pressure–temperature phase diagram, with melting conditions increasing to much higher temperatures than previous extrapolations would imply.
The role of ultrafast structural dynamics with physical and chemical changes in polydimethylsiloxane thin films by two-dimensional IR spectroscopy
Authors: Olson Courtney M. , Massari Aaron M.
Published: May 2021

Fourier transform infrared (FTIR) and two-dimensional IR (2D-IR) spectroscopies were applied to polydimethylsiloxane (PDMS) cross-linked elastomer films. The vibrational probe for the systems studied was a silicon hydride mode that was covalently bound to the polymer chains. The structure and dynamics reported by this mode were measured in response to a wide range of chemical and physical perturbations, including elevated curing temperature, increased curing agent concentration, mechanical compression, and cooling to near the glass transition temperature. The FTIR spectra were found to be relatively insensitive to all of these perturbations, and 2D-IR spectroscopy revealed that this was due to the overwhelming influence of heterogeneity on the spectral line shape. Surprisingly, the deconvoluted spectral line shapes showed that there were only slight differences in the heterogeneous and homogeneous dynamics even with the drastic macroscopic changes occurring in different systems. In the context of modeling polymer behavior, the results confirm that dynamics on the ultrafast time scale need not be included to properly model PDMS elasticity.
Global existence and long time behavior of the generalized Camassa–Holm equation with k + 1 degree nonlinearities
Authors: Jiang Zaihong , Zhang Qingning , Zhu Mingxuan
Published: May 2021

In this paper, we investigate the generalized Camassa–Holm equation with k + 1 degree nonlinearities. The global existence is established, provided that 0 < b < k and the initial data y0=(1−∂x2)u0 do not change sign. Long time behavior for the support of momentum density is obtained, and more precisely, we deduce the limit of the support of momentum density as t goes to +∞.
Position-controlled remote epitaxy of ZnO for mass-transfer of as-deployed semiconductor microarrays
Authors: Jin Dae Kwon , Choi Joonghoon , Jeong Junseok , Kang Bong Kyun , Wang Qingxiao , Yang Woo Seok , Kim Moon J. , Hong Young Joon
Published: May 2021

We report the site-selective remote epitaxial growth of mechanically transferable ZnO microrod (MR) and microdisk (MD) arrays via hydrothermal growth. To designate the growth sites, a hole-patterned poly(methyl methacrylate) mask layer is formed on the graphene-coated GaN substrate. ZnO microarrays are exclusively grown to be either MR or MD on graphene-exposed patterned areas via the remote epitaxy. The remote heteroepitaxial relation between ZnO and GaN across graphene is observed by atomic resolution scanning transmission electron microscopy. The non-covalent remote epitaxial interface allows the mechanical lift-off of the ZnO microarrays and mass-transfer onto a surface of interest using a sticky tape as those arrays are well maintained. The donor substrate is refurbished for repetitive position-controlled remote epitaxy. This study provides a simple method of fabricating mass-transferable microarrays of semiconductors that can maintain the addressable spatial arrays of semiconductors to an arbitrary receiver substrate for ease of heterogeneous integration without an additional assembly process for position control.
Extended magnesium and calcium force field parameters for accurate ion–nucleic acid interactions in biomolecular simulations
Authors: Cruz-León Sergio , Grotz Kara K. , Schwierz Nadine
Published: May 2021

Magnesium and calcium play an essential role in the folding and function of nucleic acids. To correctly describe their interactions with DNA and RNA in biomolecular simulations, an accurate parameterization is crucial. In most cases, the ion parameters are optimized based on a set of experimental solution properties such as solvation free energies, radial distribution functions, water exchange rates, and activity coefficient derivatives. However, the transferability of such bulk-optimized ion parameters to quantitatively describe biomolecular systems is limited. Here, we extend the applicability of our previous bulk-optimized parameters by including experimental binding affinities toward the phosphate oxygen on nucleic acids. In particular, we systematically adjust the combination rules that are an integral part of the pairwise interaction potentials of classical force fields. This allows us to quantitatively describe specific ion binding to nucleic acids without changing the solution properties in the most simple and efficient way. We show the advancement of the optimized Lorentz combination rule for two representative nucleic acid systems. For double-stranded DNA, the optimized combination rule for Ca2+ significantly improves the agreement with experiments, while the standard combination rule leads to unrealistically distorted DNA structures. For the add A-riboswitch, the optimized combination rule for Mg2+ improves the structure of two specifically bound Mg2+ ions as judged by the experimental distance to the binding site. Including experimental binding affinities toward specific ion binding sites on biomolecules, therefore, provides a promising perspective to develop a more accurate description of metal cations for biomolecular simulations.
Bifurcation analysis for a flow of viscoelastic fluid due to peristaltic activity
Authors: Ullah Kaleem , Ali Nasir , Hussain Sadaqut
Published: May 2021

In this article, bifurcation analysis is performed to study the qualitative nature of stagnation points and various flow regions for a peristaltic transport of viscoelastic fluid through an axisymmetric tube. The rheological behavior of viscoelastic fluid is characterized by the simplified Phan–Than–Tanner fluid model. An analytic solution in a wave frame is obtained subject to the low Reynolds number and long wavelength approximations. The stagnation points and their bifurcations (critical conditions) are explored by developing a system of autonomous differential equations. The dynamical system theory is employed to examine the nature and bifurcations of obtained stagnation points. The ranges of various flow phenomena and their bifurcations are scrutinized graphically through global bifurcation diagrams. This analysis reveals that the bifurcation in the flow is manifested at large flow rate for high extensional parameter and Weissenberg number. Backward flow phenomenon enhances and trapping diminishes with an increase in the Weissenberg number. At the end, the results of present analysis are verified by making a comparison with the existing literature.
Photofragment ion imaging in vibrational predissociation of the H2O+Ar complex ion
Authors: Nakashima Yuji , Ito Yuri , Kominato Mizuhiro , Ohshimo Keijiro , Misaizu Fuminori
Published: May 2021

Vibrational predissociation processes of the H2O+Ar complex ion following mid-infrared excitations of the OH stretching modes and bending overtone of the H2O+ unit were studied by photofragment ion imaging. The anisotropy parameters, β, of the angular distributions of the photofragment ions were clearly dependent on the type (branch) of rotational excitation, β > 0 for the P-branch excitations, while β < 0 for the Q-branch excitations, which were consistent with the previous theoretical predictions for the rotationally resolved optical transition of a prolate symmetric top. The translational energy distributions had a similar form, irrespective of the excitation modes. This result suggests that the prepared excited states underwent a common relaxation pathway via the bending or bending overtone state of the H2O+ unit. In addition, the available energy was preferentially distributed into the rotational energy of the H2O+ fragment ions rather than the translational energy. The mechanism of the rotational excitations of the H2O+ fragment ions was discussed based on the steric configuration of the H2O+ and Ar units at the moment of dissociation.
Magnetocrystalline anisotropies in MnxPtSn thin films
Authors: Swekis Peter , Markou Anastasios , Sichelschmidt Jörg , Felser Claudia , Goennenwein Sebastian T. B.
Published: May 2021

The magnetic anisotropy determines the equilibrium orientation of the magnetization in a ferromagnet. In Mn-based inverse tetragonal Heusler compounds, a large uniaxial anisotropy makes these materials excellent candidates for both spin-transfer-torque and skyrmionic devices. Here, we present systematic investigations of the magnetocrystalline anisotropies in MnxPtSn films (x = 1.0–1.6). We find that the MnxPtSn films, grown by magnetron sputtering on MgO substrates, show a structural transition between x = 1.0 and 1.2 from cubic to tetragonal, where the tetragonal structure shows a twinned in-plane c-axis orientation. From ferromagnetic resonance measurements, we determine the out-of-plane and in-plane uniaxial anisotropies, taking into account the particular structural properties of the films. We find a strong dependence of the uniaxial anisotropies on the Mn concentration, as well as on structural distortions due to the lattice-matched growth. From temperature-dependent ferromagnetic resonance measurements, we infer the evolution of the in-plane uniaxial anisotropy and observe the presence of additional magnetic interactions and magnetization relaxation mechanisms around the spin reorientation transition.
Mpemba-like effect in driven binary mixtures
Authors: Gómez González Rubén , Khalil Nagi , Garzó Vicente
Published: May 2021

The Mpemba effect occurs when two samples at different initial temperatures evolve in such a way that the temperatures cross each other during the relaxation toward equilibrium. In this paper, we show the emergence of a Mpemba-like effect in a molecular binary mixture in contact with a thermal reservoir (bath). The interaction between the gaseous particles of the mixture and the thermal reservoir is modeled via a viscous drag force plus a stochastic Langevin-like term. The presence of the external bath couples the time evolution of the total and partial temperatures of each component allowing the appearance of the Mpemba phenomenon, even when the initial temperature differences are of the same order of the temperatures themselves. Analytical results are obtained by considering multitemperature Maxwellian approximations for the velocity distribution functions of each component. The theoretical analysis is carried out for initial states close to and far away (large Mpemba-like effect) from equilibrium. The former situation allows us to develop a simple theory where the time evolution equation for the temperature is linearized around its asymptotic equilibrium solution. This linear theory provides an expression for the crossover time. We also provide a qualitative description of the large Mpemba effect. Our theoretical results agree very well with computer simulations obtained by numerically solving the Enskog kinetic equation by means of the direct simulation Monte Carlo method and by performing molecular dynamics simulations. Finally, preliminary results for driven granular mixtures also show the occurrence of a Mpemba-like effect for inelastic collisions.
Revisiting D2-law for the evaporation of dilute droplets
Authors: Dalla Barba F. , Wang J. , Picano F.
Published: May 2021

In a wide range of applications, the estimate of droplet evaporation time is based on the classical D2-law, which, assuming a fast mixing and fixed environmental properties, states that the droplet surface decreases linearly with time at a determined rate. However, in many cases the predicted evaporation rate is overestimated. In this Letter, we propose a revision of the D2-law capable of accurately determining droplet evaporation rate in dilute conditions by a proper estimate of the asymptotic droplet properties. Besides a discussion of the main assumptions, we tested the proposed model against data from direct numerical simulations finding an excellent agreement for predicted droplet evaporation time in dilute turbulent jet-sprays.
The new dynamics of residential aged care in Australia: continuity and change
Authors: Cooper-Stanbury Mark , Howe Anna L.
Published: May 2021

Objective This paper tests the hypothesis that increases in recorded dependency levels of permanent residential aged care clients are associated with reduced length of stay and higher turnover. A secondary objective is to compare the Aged Care Funding Instrument with its predecessor, the Resident Classification Scale, on a common schema. Methods Administrative data for all Commonwealth-subsidised residential aged care services in Australia from 2008–09 to 2018–19 were obtained from the National Aged Care Data Clearinghouse. More than 750 000 episodes of permanent residential aged care were analysed. The categories from the two rating systems were mapped to a six-level schema, primarily based on the dollar value of the categories at the time of transition. Results There was a strong trend towards higher dependency ratings across admissions, residents, and separations. However, contrary to expectation, measures of system activity showed a slowing of the system: length of stay increased and turnover decreased. Conclusions The mapping of dependency rating schemes to a common rating enables the analysis of long-term trends in residential care dynamics. There is no evidence that the marked increases in reported dependency ratings led to accelerated system activity, consistent with an earlier study. This analysis forms a solid base for ongoing analysis of care appraisals in the context of a possible new rating scheme. It highlights the interplay between policy changes and provider behaviour, and the need for robust data to monitor care appraisals and system dynamics. What is known about the topic? Residential aged care subsidies are determined by care needs in relation to assessed dependency levels, using the Aged Care Funding Instrument since 2008, and before that, the Resident Classification Scale. Between 2008–09 and 2018–19, there was considerable growth in residents classified at more dependent levels, and this would be expected to result in greater turnover in the system. What does this paper add? This paper maps the rating schemes to a simplified, common rating that enables the analysis of long-term trends in residential care dynamics. It shows that the system is slowing, contrary to the trends expected if residents were more frail as the reported ratings imply. The paper examines possible explanations of these trends, and addresses policy implications. What are the implications for practitioners? In the context of a potential new client-dependency classification, this study shows the importance of robust measures of the dynamics of the system—and the underlying data—vis-à-vis the means by which client dependency is assessed.
Stomata coordinate with plant hydraulics to regulate transpiration response to vapour pressure deficit in wheat
Authors: Ranawana S. R. W. M. C. J. K. , Siddique K. H. M. , Palta J. A. , Stefanova K. , Bramley H.
Published: May 2021

Genotypic variation in transpiration (Tr) response to vapour pressure deficit (VPD) has been studied in many crop species. There is debate over whether shoots or roots drive these responses. We investigated how stomata coordinate with plant hydraulics to mediate Tr response to VPD and influence leaf water status in wheat (Triticum aestivum L.). We measured Tr and stomatal conductance (gs) responses to VPD in well-watered, water-stressed and de-rooted shoots of eight wheat genotypes. Tr response to VPD was related to stomatal sensitivity to VPD and proportional to gs at low VPD, except in the water-stressed treatment, which induced strong stomatal closure at all VPD levels. Moreover, gs response to VPD was driven by adaxial stomata. A simple linear Tr response to VPD was associated with unresponsive gs to VPD. In contrast, segmented linear Tr to VPD response was mostly a function of gs with the breakpoint depending on the capacity to meet transpirational demand and set by the shoots. However, the magnitude of Tr response to VPD was influenced by roots, soil water content and stomatal sensitivity to VPD. These findings, along with a theoretical model suggest that stomata coordinate with plant hydraulics to regulate Tr response to VPD in wheat.
Membrane fusion and drug delivery with carbon nanotube porins
Authors: Ho Nga T. , Siggel Marc , Camacho Karen V. , Bhaskara Ramachandra M. , Hicks Jacqueline M. , Yao Yun-Chiao , Zhang Yuliang , Köfinger Jürgen , Hummer Gerhard , Noy Aleksandr
Published: May 2021

Significance

The plasma membrane protects cell content from the outer environment. Overcoming this obstacle and delivering drugs efficiently into cells still remain a major hurdle for modern pharmacology and medicine. We developed and demonstrated a simple nanomaterial platform—a dimer of small-diameter carbon nanotube porins (CNTPs)—which functions as a potent membrane fusogen. Molecular simulations revealed a distinct fusion mechanism. CNTP-studded vesicles loaded with a chemotherapeutic agent, doxorubicin, delivered the drug to cancer cells, killing a majority of them. Our work provides new opportunities for understanding membrane fusion mechanisms, designing synthetic fusogens, and developing simple and efficient drug carriers for delivery of therapeutics and vaccines.
The genomes of ancient date palms germinated from 2,000 y old seeds
Authors: Gros-Balthazard Muriel , Flowers Jonathan M. , Hazzouri Khaled M. , Ferrand Sylvie , Aberlenc Frédérique , Sallon Sarah , Purugganan Michael D.
Published: May 2021

Significance

Resurrection genomics is an alternative to ancient DNA approaches in studying the genetics and evolution of past and possibly extinct populations. By reviving biological material such as germinating ancient seeds from archaeological and paleontological sites, or historical collections, one can study genomes of lost populations. We applied this approach by sequencing the genomes of seven Judean date palms (
Phoenix dactylifera
) that were germinated from ∼2,000 y old seeds recovered in the Southern Levant. Using this genomic data, we were able to document that introgressive hybridization of the wild Cretan palm
Phoenix theophrasti
into date palms had occurred in the Eastern Mediterranean by ∼2,200 y ago and examine the evolution of date palm populations in this pivotal region two millennia ago.
Anatomy of strike-slip fault tsunami genesis
Authors: Elbanna Ahmed , Abdelmeguid Mohamed , Ma Xiao , Amlani Faisal , Bhat Harsha S. , Synolakis Costas , Rosakis Ares J.
Published: May 2021

Significance

Our work has uncovered unexpected potential for strike-slip faults to generate devastating tsunamis, without necessarily triggering coseismic underwater landslides or slumps with their associated wave generation. This is a previously unrecognized hazard for coastal cities worldwide. The risk is higher for supershear earthquakes, as in the 1999 Izmit and the 2018 Palu events, which may be the case for an earthquake rupturing the northern segment of the San Andreas Fault.
Identification of PUFA interaction sites on the cardiac potassium channel KCNQ1
Authors: Yazdi Samira , Nikesjö Johan , Miranda Williams , Corradi Valentina , Tieleman D. Peter , Noskov Sergei Yu. , Larsson H. Peter , Liin Sara I.
Published: May 2021

Polyunsaturated fatty acids (PUFAs), but not saturated fatty acids, modulate ion channels such as the cardiac KCNQ1 channel, although the mechanism is not completely understood. Using both simulations and experiments, we find that PUFAs interact directly with the KCNQ1 channel via two different binding sites: one at the voltage sensor and one at the pore. These two amphiphilic binding pockets stabilize the negatively charged PUFA head group by electrostatic interactions with R218, R221, and K316, while the hydrophobic PUFA tail is selectively stabilized by cassettes of hydrophobic residues. The rigid saturated tail of stearic acid prevents close contacts with KCNQ1. By contrast, the mobile tail of PUFA linoleic acid can be accommodated in the crevice of the hydrophobic cassette, a defining feature of PUFA selectivity in KCNQ1. In addition, we identify Y268 as a critical PUFA anchor point underlying fatty acid selectivity. Combined, this study provides molecular models of direct interactions between PUFAs and KCNQ1 and identifies selectivity mechanisms. Long term, this understanding may open new avenues for drug development based on PUFA mechanisms.
Developing parking queue monitoring system using Wireless Sensor Network and RFID technology
Authors: Santoso Banu , Sari Marti Widya
Published: May 2021

Parking areas in urban centers are increasingly limited, but not in line with technological developments in addressing the problem of parking service needs in the urban public service center by implementing smart city technology. Many times the parking service waiting time is too long, due to a complicated procedure. Waiting time for services that are too long makes the parking queue increase in length, especially when registering for the end of a new parking lot. Besides, the storage of visitors’ parking slip accumulation is still manual and not paperless. Therefore, in this study, a solution was proposed in the form of a system to accelerate administrative services for parking visitors by integrating Radio Frequency Identification (RFID) and Wireless Sensor Network (WSN) technologies. This system utilizes the database so that the results of data processing can be used by management to obtain visitor data information on parking online and quickly. The results obtained from this study are a prototype of a parking visitor monitoring system using WSN technology based on Zigbee and RFID protocols. Meanwhile, the results of visitor parking information presented in data processing can be used by management to find out statistical data relating to parking services.
Analysis Creative Thinking Ability and Scientific Communication in HOTS Learning Using Whatsapp Media
Authors: Ahmad Deni Nasir , Karim Abdul , Zulkarnain Ihwan , Ati Aster Pujaning , Nusantari Diah Oga
Published: May 2021

The purpose of knowing whenever the achievement of HOT learning through WhatsApp media is to measure the ability to communicate scientifically and think creatively in solving problems related to current problems related to the Covid-19 outbreak in the Population and Environmental Education (PKLH) course. The method used in quantitative research. Where a sample of 30 students in the even academic year 2019/2020 in the physics education study program, Indraprasta PGRI University. The results of the study were students’ communication skills at good stages which were 63.3 percent of all existing activities, discussion and reporting of activity results. This is in line with the results of research which explained that the ability to communicate using blended learning and Inquiry will produce scientific communication with an increase above the average learning rate which previously increased by 9% to 15% at the level of each indicator of the student’s creative thinking ability test at good or moderate stages with an average of 63% to 73% based on an indicator of test ability. The conclusion in this research is HOT learning with whatsapp media in the experiment, the ability to communicate scientifically and the ability to think creatively has a positive or good change.
Determinant factors of extraordinary elementary school teacher professionalism
Authors: Kurniawan Wahyu , Su’ad  , Sukirman
Published: May 2021

This study aims to determine the effect of education, training, and teaching experience on the professionalism of Extraordinary Elementary School teachers in Kudus Regency. This research is an explanatory research with a quantitative approach. The research subjects were 63 SDLB teachers in Kudus Regency. The sampling technique was carried out by total sampling. The method of collecting data using a questionnaire. Data analysis using multiple regression analysis. The results showed that education, training and teaching experience had a significant effect on the professionalism of Extraordinary Elementary School teachers in Kudus Regency. The coefficient of determination (R2) of 0.687 shows that the influence of education, training and teaching experience on teacher professionalism is 68.7%. Teaching experience has the greatest influence on teacher professionalism.
Development of social studies teaching materials based on local wisdom of the Samin Society Class V Elementary School
Authors: Nurhamid H , Murtono  , Utaminingsih S
Published: May 2021

This study aims to describe the needs of teachers and students for samin society-based learning materials social study class V elementary school, and to analyzing the effectiveness. This research is a development research that uses ten steps, namely analysis of potentials and problems, gathering information, product design, design validation, design revision, product testing, product revision, and use trial, final product revision and dissemination. The practicality test and effectiveness test were conducted on 74 grade 5 students as the experimental class. Data collection used teaching material assessment sheets, practicality questionnaires, and tests of students’ cognitive learning outcomes. Data analysis techniques used validation sheet analysis, practicality questionnaire analysis, teacher and student response questionnaires, and t-test acquisition analysis to determine the effectiveness of samin society-based teaching materials social study. Teaching materials developed with effectiveness data which were then analyzed by normality test, test homogeneity, t test. The results of the t test obtained the value of t = 3.796. The t table value for df = 80 with a significant level of 5% is known to be 1.988. The conclusion is that social studies teaching materials assisted by local wisdom of the samin society are effective in improving social learning outcomes in elementary schools.
Mechanical Properties of Silver Nanoparticles Induced Europium Doped Phosphate Glasses for Red Laser Application
Authors: Danmallam I.M. , Bakhtiar H , Salim A.A. , Bulus I , Ghoshal S K
Published: May 2021

Magnesium-zinc-sulfophosphate glasses with varying concentration of Silver nanoparticles (AgNPs) composition of 63.5P2O5–20MgO–15ZnSO4–1.5Eu2O3–zAgNps (z = 0.0, 0.1, 0.3, 0.5, 0.7,0.9 and 1.1 g in excess) was prepared using melt-quenching technique. The as-Quenched glass samples were characterised to ascertain the correlation between physical and mechanical characteristics. The enhanced Young’s, shear, and bulk modulus of glasses noted a comparative rise in AgNPs contents. The Poisson’s ratio improved from (0.0978 to 0.1416) while Vickers hardness (from 0.0658 to 0. 0.0682 GPa) as well as GC12 (from 0.8350 to 0.8916) were enhanced. Photoluminescence spectra (emission) of the glasses showed four peaks at 593, 613, 654, and 701 nm equivalent to 5D0→7F0, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transitions in europium in which the intense peak was observed at 613 nm (red). High Quantum Efficiency (η = 97.9%) was achieved due to significant PL enhancement. The studied glass may be useful for the development of red laser
Aluminum Doping Contents Dependent Photoluminescence and Resistivity of ZnO Nanofilms
Authors: Al-Asedy H.J. , Al-khafaji S.A. , Salim A. A. , Bakhtiar H.
Published: May 2021

Using sol–gel spin-coating technique Al-doped ZnO nanofilms (AZONFs) were made on Si(100) substrates and characterized. The obtained nanofilms were annealed at 500 °C for 3 h in air. The effects of changing Al doping level (0 to 5 at%) on the structures, morphologies, electrical and photoluminescence characteristics of the nanofilms were evaluated. The XRD patterns of the AZONFs confirmed the formation of wurtzite hexagonal ZnO lattice with preferred growth along (101) lattice plane. In addition, the c-axis orientation of the AZONFs became weaker with the increase in Al doping contents. The surface morphologies, structures, electrical and optical properties of the AZONFs were found to be very sensitive to the Al contents changes. The nanofilm prepared with 1 at% of Al displayed lowest resistivity of 4.238 × 10−3 Ω.cm measured by the four-point probe method. The optical band gap energy (increased from 3.22 to 3.304 eV) and carrier mobility of the AZONFs were improved with the increase in Al contents. The proposed AZONFs may be advantageous for various high performance optoelectronic device applications.
Laser Induced Breakdown Spectroscopic Investigation and Discrimination of Sabah’s Pearl
Authors: Roslan M S , Rizvi S Z H , Razak S N A , Rosley R , Adnan N N , Hamzah M Q , Ali A H , Agam A
Published: May 2021

Natural pearls have different composition that give them specific properties such as colour, lustre effect and can be classified based on differentiation of various constituents such as crystal phase and the presence of various minerals. The aim of this study was to develop a fast, simple, and non-destructive method for discrimination of the popular Sabah’s pearl that commonly used for bracelet, earring, and necklace. In order to discriminate pearls of different colours, emission spectroscopic method, namely laser-induced breakdown spectroscopy (LIBS) complimented with principal component analysis (PCA) was used. PCA model showed that the first principal component explained 96.44% of the total variance. Calcium, Mercury, and Barium elements mainly deexcited at wavelength 600 to 900 nm attributing to the most effective variables for PC1 while Manganese, and Silicon content were useful in defining PC2. PCA demonstrated clear clustering of pearl samples of different colors. Thus, became a major indicator for successful discrimination of natural pearls of various colors using LIBS spectral data. We can confidently say that this can be made available to use by gems industry for performing a fast quality control of inflowing raw organogenic gems.
Pulsed Laser Performance of Erbium Doped Fiber Laser Using Titanium Dioxide Nanoparticles as Saturable Absorber
Authors: Johari AR , Krishnan G , Bakhtiar H , Sapingi HHJ
Published: May 2021

In this work, titanium dioxide TiO2 nanoparticles embedded in thin composite film was used as saturable absorber (SA) in erbium doped fiber (EDF) laser. The thin film was prepared by mixing TiO2 nanoparticles with polyvinyl alcohol (PVA) as host. Upon inserting the SA in a laser cavity, the output spectrum shifts to 1533.4 nm from 1563.8 nm. The laser performance was evaluated in the pump power range of 76 mW – 131 mW. The repetition rate of the mode-locked pulses was 989.0 kHz with a pulse width of 1.26 ps measured. The slope efficiency of the system is 8.58%. Maximum average power and peak power generated from the laser is 11.69 mW and 9.41 kW, respectively. This work explored the potential of TiO2-PVA thin film as saturable absorber for 1.5 μm laser system.
Interpreting the G-code of drilling machining to use in open CNC controller machine
Authors: Hatem Noor , Yusof Yusri , Kadir Aini Zuhra A , Latif Kamran , Mohammed M A
Published: May 2021

Computer numerical control (CNC) software is the “brain” of a machine tool as it controls the machine tool’s movement. The development of open CNC controller systems is one of the most popular topics in the last three decades due to the current CNC remains exclusive and costly. However, there is no open-source system that can use with an open CNC controller. In this developed system, the drilling G-code was analyzed to extract the points before simulating and sending it to any open CNC controller machine. Among the machining processes used most extensively is drilling. The used modules and functions are created by LabVIEW. The results show the system’s extracted points are similar to the draw drilling point in Solid work.
Gold-Nanoparticle Synthesization In Gum Arabic Solution By Pulsed Laser Ablation
Authors: Desa Nur Dayana Md , Duralim Maisarah
Published: May 2021

Green synthesis of nanoparticles is crucial to effectively reduce the risk to the environment by eradicating hazardous components that are harmful to human health. The broad complications such as aggregation and oxidation of nanoparticles will potentially limit their usage. Gum Arabic (GA) has attained decent attention due to less toxicity and bio-compatibility with metals. Gold-nanoparticles (Au-NPs) have several applications in diagnosing cancer, targeted delivery of drugs and in cancer treatment. This project is conducted by synthesizing Au-NPs in GA solution via pulsed laser ablation in liquid (PLAL) technique at varied laser fluences. A Q-switched Nd:YAG laser with wavelength of 1064 nm was focused using a lens with a focal length of 80 mm to ablate a gold plate immersed in GA solution. Four different laser fluences were tested. The laser fluences were 0.203, 0.214, 0.250 and 0.272 J. The Au-NPs synthesized in the GA solution were then characterized using photoluminescene (PL) and UV-Visible double beam spectrometer (UV-Vis). The highest laser fluence has shown the highest intensity while the wavelength of all peaks is the same indicating the same nanomaterials being synthesized in each sample. The UV-Vis spectra indicated that the absorbance increases as the holding time is prolonged. It is believed that the formation of Au-NPs is a nucleating process and followed by a growing process.
Naked Eye Colorimetric Glucose Detection Using Microplate Reader
Authors: Azahan Siti Nurul Fatihah , Nasir Mohd Hamzah Mohd , Salleh Mohd Hazimin Mohd
Published: May 2021

Diabetes in general can be classified as Type 1, Type 2, gestational diabetes mellitus that occur during pregnancy, and specific types of diabetes due to certain health condition. Monitoring glucose level is crucial in order to maintain a healthy lifestyle, especially among diabetic patients. Today, researchers looking for a less painful, cheap, and user-friendly noninvasive method to monitor the body glucose level. One of the promising approaches is sweat based glucose detection. In order to calibrate the sensing device, we determined the limit of detection of the glucose concentration in sweat liquid by the well-established enzymatic reaction. This paper will discuss the utilisation of a microplate reader to measure the sensitivity of the chromogenic change in reaction. 50μL of glucose oxidase-peroxidase (GOD-POD) enzyme and 1.67μL glucose sample with different concentrations were mixed in 96 well flat bottom microplate, and the absorbance were detected by using a microplate reader. The absorbance value was used to calculate the concentration. The calculated concentration was compared with the known concentration. From the experimental procedure, the results showed the consistency of calculated and known concentration and R2 = 0.9995
Free-Base Porphyrins as Chemical Probes for Heavy Metal Ions Detection
Authors: Mohamad F , Ami A A , Aziz M S Abd
Published: May 2021

Heavy metals are one of the major contaminants in water. They come from various human activities which include mining, smelting, and industrial discharge to name a few. Heavy metals pose a toxic danger to human beings even at their minute concentration. Current methods of detection suffer from numerous limitations such as complicated sample preparation, high cost of instruments, and the need for professional chemists. These challenges make them unsuitable for in situ and real-time monitoring of samples. Fluorescence spectroscopy has emerged as an alternative for sensing applications. They have high sensitivity, good selectivity, and only require small amounts of fluorescent probes. In this study, free base porphyrins were selected as a fluorescent chemical probe to detect the presence of commonly discharge heavy metals – lead (Pb2+) ions and nickel (Ni2+) ions. Solution-based assay and fluorescent measurements were used throughout the study. From the fluorescent analysis, porphyrins showed more selective and sensitivity towards Pb2+ ions. The study also investigated the photostability of porphyrins when porphyrins solutions were put under ambiance light conditions. This solution-based assay fluorescent measurement shows promising potential application of porphyrins to be used as chemical probes on another sensor medium such as on optical fibre and thin film study.
In Vitro Effects of Low Level Laser Irradiation on Blood Protein
Authors: Suardi N , Sing H C , Gemanam S J , Ong E B B , Pei W Z
Published: May 2021

Blood proteins serve mostly as drug’s transporters and play a crucial role in laser therapeutic purposes. Its low level laser irradiation (LLLI) reveals the mechanisms for the efficacy of antiviral therapy. This research work is interested in elucidating protein (ceruloplasmin, fibrinogen (α-chain), complement C2, albumin, and α-1-antitrypsin) level perturbation by single (single exposure) and multiple exposures (fractionation) LLLI. Protein level after LLLI reveals protein behaviour essential for progression of laser therapy used in protein-related pathologies. Whole blood (mixed with EDTA) irradiation performed with diode laser (λ = 405 nm). Optical microscope and polyacrylamide gel electrophoresis were used for RBC morphology image acquisition and semi-quantification of protein level respectively. Our results showe that crenated RBC has minimal effect on protein level perturbation for dose between 32.59 J/cm2 and 130.35 J/cm2, single exposure has an overall increased protein level for all five proteins at dose 130.35 J/cm2, and multiple exposures has an overall decreased protein level for all five proteins at dose 97.77 J/cm2. Optical density change was seen most in fibrinogen (α-chain) and least in albumin for single (fibrinogen (α-chain): 423 %; albumin: 59 %) and multiple exposures (fibrinogen (α-chain): -71 %; albumin: -30 %). A large variation in protein level perturbation for high molecular weight proteins, while slight variation for low molecular weight proteins were also observed for single exposure at dose 130.35 J/cm2 (except α-1-antitrypsin at 32.59 J/cm2). This data provides evidence of the biostimulation effects of low level laser irradiation on blood proteins and the 2 hours’ adequate incubation time for decreasing protein level.