bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural phase transitions and photoluminescence mechanism in a layer of 3D hybrid perovskite nanocrystals
Authors: Glinka Yuri D. , Cai Rui , Gao Xian , Wu Dan , Chen Rui , Sun Xiao Wei
Published: June 2020

Although structural phase transitions in single-crystal hybrid methyl-ammonium (MA) lead halide perovskites (MAPbX3, X = Cl, Br, I) as a function of temperature are common phenomena, they have never been observed in the corresponding nanocrystals. Here, we demonstrate that two-photon-excited photoluminescence (PL) spectroscopy is capable of monitoring structural phase transitions in MAPbX3 nanocrystals because nonlinear susceptibilities govern the incident light absorption rates. We provide experimental evidence that the orthorhombic-to-tetragonal structural phase transition in a single layer of 20-nm-sized 3D MAPbBr3 nanocrystals is spread out within the T ∼ 70 K–140 K temperature range. This structural phase instability is believed to arise because, unlike in single-crystal MAPbX3, free rotations of MA ions in the corresponding nanocrystals are no longer restricted by a long-range MA dipole order. The resulting configurational entropy loss can be even enhanced by the interfacial electric field arising due to charge separation at the MAPbBr3/ZnO heterointerface, extending the structural phase instability range from T ∼ 70 K–230 K. We conclude that weak sensitivity of conventional one-photon-excited PL spectroscopy to structural phase transitions in 3D MAPbX3 nanocrystals results from structural phase instability and hence from negligible distortions of PbX6 octahedra. In contrast, the intensity of two-photon-excited PL and electric-field-induced one-photon-excited PL show higher sensitivity since nonlinear susceptibilities are involved. We also show that room-temperature PL may originate from the radiative recombination of the optical-phonon vibrationally excited polaronic excitons with energies might exceed the ground-state Fröhlich polaron and Rashba energies due to optical-phonon bottleneck.
Using curvature to select the time lag for delay reconstruction
Authors: Deshmukh Varad , Bradley Elizabeth , Garland Joshua , Meiss James D.
Published: June 2020

We propose a curvature-based approach for choosing a good value for the time-delay parameter τ in delay reconstructions. The idea is based on the effects of the delay on the geometry of the reconstructions. If the delay is too small, the reconstructed dynamics are flattened along the main diagonal of the embedding space; too-large delays, on the other hand, can overfold the dynamics. Calculating the curvature of a two-dimensional delay reconstruction is an effective way to identify these extremes and to find a middle ground between them: both the sharp reversals at the extremes of an insufficiently unfolded reconstruction and the bends in an overfolded one create spikes in the curvature. We operationalize this observation by computing the mean Menger curvature of a trajectory segment on 2D reconstructions as a function of time delay. We show that the minimum of these values gives an effective heuristic for choosing the time delay. In addition, we show that this curvature-based heuristic is useful even in cases where the customary approach, which uses average mutual information, fails—e.g., noisy or filtered data.
Magnetocaloric effect in GdNi2 for cryogenic gas liquefaction studied in magnetic fields up to 50 T
Authors: Taskaev Sergey , Khovaylo Vladimir , Skokov Konstantin , Liu Wei , Bykov Eduard , Ulyanov Maxim , Bataev Dmitriy , Basharova Anastasiya , Kononova Marina , Plakhotskiy Daniil , Bogush Mikhail , Gottschall Tino , Gutfleisch Oliver
Published: June 2020

Natural gases have played a significant role in different sectors of the global economy. Recent analyses have shown that the world's gas consumption doubled over the last three decades; further growth of the gas consumption is predicted, rising to be 23%–28% of the total primary energy demand by 2030. Therefore, liquefaction of natural gases rapidly gains global importance. In this context, magnetic refrigeration emerges as a modern energy-saving technique, which is an alternative to the traditional gas-compression refrigeration. This paper is devoted to the study of the magnetocaloric effect in magnetic fields up to 10 T on a representative of the Laves phase alloys, GdNi2, which is considered as a perspective material for liquefaction of natural gases. For a magnetic field change of 10 T, the magnetic entropy change ΔSm ≈ −17 J/kg K and the adiabatic temperature change ΔTad ≈ 6.8 K was attained around Curie temperature TC = 70 K. The maximal value of the adiabatic temperature change measured directly in pulsed magnetic fields up to 50 T is ΔTad ≈ 15 K.
Reactions of translationally cold trapped CCl+ with acetylene (C2H2)
Authors: Catani K. J. , Greenberg J. , Saarel B. V. , Lewandowski H. J.
Published: June 2020

Ion–neutral chemical reactions are important in several areas of chemistry, including in some regions of the interstellar medium, planetary atmospheres, and comets. Reactions of CCl+ with C2H2 are measured, and the main products include C3H2+ and C3H+, both relevant in extraterrestrial environments. Accurate branching ratios are obtained, which favor the formation of C3H2+ over C3H+ by a factor of four. The measured rate constants are on the order of Langevin, and complementary electronic structure calculations are used to aid in the interpretation of experimental results.
Self-assembly in amphiphilic spherical brushes
Authors: Pu Wan-Fen , Ushakova Alexandra , Liu Rui , Lazutin Alexei A. , Vasilevskaya Valentina V.
Published: June 2020

The structure of amphiphilic spherical brushes, consisting of the nano-SiO2 core, the hyperbranched polyamidoamine subshell, and a grafted layer of long hydrophobically modified polyacrylamide (HMPAM) chains, in aqueous solution was analyzed and described in the framework of the original mean-field approach. The scaling estimations of the hydrodynamic radius of such polymer brushes as a function of the number of grafted macromolecules allow concluding that the HMPAM shells are in a globular state and that the region of the stretched chains adjacent to the grafting surface is a minor part of the grafted macromolecules and does not have a significant impact on the self-assembly of the HMPAM shell caused by the complex hydrophobic–hydrophilic composition of their monomer units. In mean-field theory, the amphiphilic nature of HMPAM was taken into account by attaching the hydrophobic side group H to some fraction of monomer units of the hydrophilic P backbone. The strong attraction of H groups causes the aggregation of macromolecules, whereas the affinity of hydrophilic P groups to solvent forces the aggregates to increase their surface. Due to such effective surface activity, in poor solvent, the grafted amphiphilic macromolecules could form a spherical compacted structure around the nanoparticle or self-assemble into a “hedgehog” structure with several “spines” having hydrophobic core and hydrophilic shell. State diagrams, obtained theoretically, reveal that the “hedgehog” structure is preferable for a wide range of energetic parameters.
Plasma-enhanced pulsed laser deposition of copper oxide and zinc oxide thin films
Authors: Rajendiran S. , Meehan D. , Wagenaars E.
Published: June 2020

Plasma-Enhanced Pulsed Laser Deposition (PE-PLD) is a technique for depositing metal oxide thin films that combines traditional PLD of metals with a low-temperature oxygen background plasma. This proof-of-concept study shows that PE-PLD can deposit copper oxide and zinc oxide films of similar properties to ones deposited using traditional PLD, without the need for substrate heating. Varying the pressure of the background plasma changed the stoichiometry and structure of the films. Stoichiometric copper oxide and zinc oxide films were deposited at pressures of 13 Pa and 7.5 Pa, respectively. The deposition rate was ∼5 nm/min and the films were polycrystalline with a crystal size in the range of 3 nm–15 nm. The dominant phase for ZnO was (110) and for CuO, they were (020) and (111¯), where (020) is known as a high-density phase not commonly seen in PLD films. The resistivity of the CuO film was 0.76 ± 0.05 Ω cm, in line with films produced using traditional PLD. Since PE-PLD does not use substrate heating or post-annealing, and the temperature of the oxygen background plasma is low, the deposition of films on heat-sensitive materials such as plastics is possible. Stoichiometric amorphous zinc oxide and copper oxide films were deposited on polyethylene (PE) and polytetrafluoroethylene (PFTE).
Heat transfer enhancement by a non-uniform electric field in microgravity conditions
Authors: Jawichian Alex , Davoust Laurent , Siedel Samuel
Published: June 2020

The role of an electric field on dielectric liquids confined in a differentially heated cavity is considered in microgravity conditions. In the purpose of sustaining permanent thermally induced electrohydrodynamic flows, a new electrode arrangement is proposed, different from the typical electrode configurations usually investigated in the literature. The aim is to generate a non-uniform distribution of the imposed electric field and to gain benefit from the existing temperature gradient to generate angular momentum. Scaling analysis and a numerical study are developed in order to investigate dielectrophoretic-induced convective heat transfers. The results show that a significant enhancement of heat transfers is made possible from the use of a non-intense non-uniform electric field with no need for giving rise to unstable regimes.
Symmetrical and anti-symmetrical topological edge states based on two-dimensional magneto-optical photonic crystals
Authors: Lai Hua-Shan , Chen Hao , He Bo , He Cheng , Chen Yan-Feng
Published: June 2020

We report our design of a topological waveguide at the boundary of two adjacent magneto-optical photonic crystals with opposite magnetic biases which can simultaneously support symmetrical and anti-symmetrical topological edge states. In this non-reciprocal topological photonic model, the symmetrical and anti-symmetrical topological edge states possess the same direction of backscattering-immune chiral energy propagation. However, their directions of phase propagation are opposite, i.e., forward phase propagation for the symmetrical state while backward for the anti-symmetrical one. Using a finite-size structure, we can selectively couple one topological edge state to free space via oblique incidence to realize one-way transmission and reflection in a compact configuration. Furthermore, we design an all-photonic tunable splitter by hybridizing these two topological states. Based on manipulating the phase propagation of topological edge states, our work may offer promising applications in tunable topological photonics and extend the scope of topological photonics.
Characterising the number and type of presentations to a tertiary emergency department by young people affected by drugs and alcohol
Authors: Nagree Yusuf , Darwent Ben
Published: June 2020

Objective The aim of this study was to investigate the frequency and type of emergency department (ED) presentations involving drugs and/or alcohol (DA) among young people. Methods A retrospective chart review was conducted of patients aged 14–25 years who presented to the ED at a tertiary hospital between 7 October and 25 November 2013. Data were collected on standardised data sheets, including whether DA was a factor in the patient’s presentation. Results In all, 713 ED presentations of patients aged 14–25 years were included in this review (mean age 20 years). Of these, 94 (13%) presentations involved DA (median blood alcohol level 0.12%; range 0.01–0.39%); among patients aged 14–17 years, 13 (8%) presentations involved DA. Patient presentations involving DA were more likely to occur overnight and at weekends, had higher Australasian Triage Scale scores and had longer ED lengths of stay. These patients were also more likely to present with aggression, because of an assault, or with mental health disorders. Conclusion DA are involved in a substantial number of presentations of young people to the ED and are associated with an increased risk of assault and aggression. Public health strategies should target the links between DA use and mental health in young people. What is known about the topic already? It is known that the use of alcohol and drugs in young people is an ongoing public health concern. Research suggests this cohort of the population is more likely to present to an ED with an injury than the comparative age group not intoxicated by drugs or alcohol, and is more likely to be reviewed after hours. Alcohol is the predominant drug that had been used by young people at the time of the present study. What does this paper add? This paper reviews the number and types of presentations to a tertiary ED. In so doing, many more areas were researched (rather than simply link to injury) and, as a result, it was found that young people present to the ED with an increased risk of mental health issues and an increased risk of aggression. The study also found that young people intoxicated with DA most commonly presented for different reasons than the same sober cohort. What are the implications for practitioners? We know that young people intoxicated with DA represent a different public health issue than the sample group, and, as a result, public health initiatives must concentrate on the confounding factors of the presenting complaint, notably education surrounding the risk of mental health disturbance and increased aggression rates. Furthermore, the study should benefit practitioners, showing that more mental health services should be available after hours for this cohort presenting with issues related to DA.
Sensitivity of leaflet growth rate to drought predicts yield in common bean (Phaseolus vulgaris)
Authors: Hageman Amber N. , Urban Milan O. , Van Volkenburgh Elizabeth
Published: June 2020

Although drought limits yield by decreasing photosynthesis and therefore biomass accumulation, biomass is not the strongest predictor of yield under drought in common beans (Phaseolus vulgaris L.). Instead, resource partitioning from pod walls into seeds is a stronger correlate. Our aim was to determine whether growth rates of developing leaflets and pods, as independent indicators of sink strength, predict resource partitioning into seeds. Using 20 field-grown genotypes, we paired biomass, yield, and resource partitioning data with leaflet and pod growth rates under well-watered and droughted conditions. We hypothesised that genotypes with faster growing leaflets and pods under drought would fill seeds better. However, we found that leaflet and pod growth rates did not predict partitioning to seeds; rather, sensitivity of leaflet growth rate to drought was a good predictor of yield reduction. Further, plants with rapidly growing leaves under well-watered conditions were most vulnerable to decreases in leaflet growth rate under drought. This suggests that lines that inherited a conservative growth strategy were better able to maintain yield by allocating resources to seeds. Our findings indicate that inherent sensitivity of leaflet growth rate to drought may be used as a predictor of partitioning and yield in common beans.
Does regretting first vaginal intercourse have an effect on young adults' sexual behaviour?
Authors: Suris Joan-Carles , Akre Christina , Jacot-Descombes Caroline , Leeners Brigitte , Morselli Davide , Barrense-Dias Yara
Published: June 2020

Background
The aims of this research were to determine personal differences depending on the reason for regretting or not first vaginal intercourse and its effects on sexual behaviour later on among young adults, and to assess the association between reasons for engaging in first vaginal intercourse and regretting it. Methods: Data were drawn from the 2017 Swiss national survey on youth sexual behaviours among young adults (mean age 26 years) living in Switzerland. Out of the 7142 participants, 4793 (51% females) answered the question ‘Looking back now to the first time you had vaginal intercourse, do you think that…’ with five possible answers: (1) I should not have done it (6.7%); (2) I should have waited longer (7.7%); (3) I should have done it earlier (7.4%); (4) It was about the right time (67.9%); and (5) I don’t know (10.3%). The five groups were compared on sociodemographic and sex behaviour-related variables, analysed separately by gender. Results: One-third of participants regretted their first experience. In the multivariate analysis, compared with the ‘right time’ group, all other groups were more likely to find their first experience unpleasant and to have done it with a casual partner. Those in the ‘I should not have done it’ and ‘I should have waited longer’ groups were also more likely to have done it because of external pressure, especially among females. Conclusions: The study results underline the significance to choose the right time and the right partner for first vaginal intercourse and the importance of including partner respect and avoiding external pressure as part of sexual education.
Knowledge transfer into sport practice: An empirical user analysis of a sport science website
Authors: Sperlich Billy , Wicker Pamela
Published: June 2020

Transferring scientific knowledge to applied practitioners presents a challenge in sport science. Knowledge transfer, conceptualized as knowledge reuse and knowledge contribution, has mainly been studied in the context of specific topics, projects, or organizations. The purposes of this study were to investigate the determinants of knowledge transfer from a publicly available website to its users and to cluster users into different groups based on their level of knowledge transfer. The website www.sportsandscience.de is dedicated to translating evidence‐based knowledge that is regularly generated in scientific studies into short and digestible information through e.g. videos and blogs, and provides opportunities for knowledge reuse and contribution. A theoretical model of knowledge transfer in organizations which was adapted to this context guided the study. Data from an online survey of registered website users were employed for the empirical analysis. The regression analyses showed that knowledge reuse is positively affected by ease of knowledge access and negatively by age. Knowledge reuse, job experience, and male gender have a significant positive effect on knowledge contribution. The findings suggest that the theoretical model is generally applicable to this context, but also highlight differences to the original organizational setting. Cluster analysis yielded three clusters: Frequent users, occasional users, and frequent contributors. Analyses of variances revealed significant differences among clusters regarding computer self‐efficacy, job experience, gender, age, employment, interested sports, and conditional skills, but not concerning education and formal qualifications. Implications for improving knowledge transfer of such a website are provided.
Deconstructing effective non-Hermitian dynamics in quadratic bosonic Hamiltonians
Authors: Flynn Vincent P , Cobanera Emilio , Viola Lorenza
Published: June 2020

Unlike their fermionic counterparts, the dynamics of Hermitian quadratic bosonic Hamiltonians are governed by a generally non-Hermitian Bogoliubov-de Gennes effective Hamiltonian. This underlying non-Hermiticity gives rise to a dynamically stable regime, whereby all observables undergo bounded evolution in time, and a dynamically unstable one, whereby evolution is unbounded for at least some observables. We show that stability-to-instability transitions may be classified in terms of a suitably generalized

P
T

symmetry, which can be broken when diagonalizability is lost at exceptional points in parameter space, but also when degenerate real eigenvalues split off the real axis while the system remains diagonalizable. By leveraging tools from Krein stability theory in indefinite inner-product spaces, we introduce an indicator of stability phase transitions, which naturally extends the notion of phase rigidity from non-Hermitian quantum mechanics to the bosonic setting. As a paradigmatic example, we fully characterize the stability phase diagram of a bosonic analogue to the Kitaev–Majorana chain under a wide class of boundary conditions. In particular, we establish a connection between phase-dependent transport properties and the onset of instability, and argue that stable regions in parameter space become of measure zero in the thermodynamic limit. Our analysis also reveals that boundary conditions that support Majorana zero modes in the fermionic Kitaev chain are precisely the same that support stability in the bosonic chain.
The dynamics of cooperation in asymmetric sub-populations
Authors: Guo H , Li X , Hu K , Dai X , Jia D , Boccaletti S , Perc M , Wang Z
Published: June 2020

Sacrificing personal benefits for a common good is at odds with the fundamental principle of Darwinian evolution: if only the fittest survives, then there should be no place for cooperation. But cooperative behavior actually abounds, and constitutes one of the most persistent and fascinating puzzles of nature. One solution to this puzzle is network reciprocity, where the collective dynamics of cooperators affords them protection against invading defectors. Commonly, however, such a competition does not unfold in isolation. Populations are often divided into sub-populations, with different evolutionary rules describing the interactions between them. Here we propose and study a paradigmatic model that captures the essence of this setup. Specifically, if two players belong to the same sub-population, they play the prisoner’s dilemma game. If not, they play either the harmony game, the snowdrift game, the stag-hunt game, or the prisoner’s dilemma game. Due to such an asymmetry in the interactions across sub-populations, a fascinating evolutionary dynamics sets up that greatly expands the survivability of cooperators. For instance, when the harmony game applies, cyclic dominance spontaneously emerges, wherein cooperators in one sub-population become predators of defectors in the other sub-population. One also may observe self-organized segregation, wherein both sub-populations maintain a mixed state of cooperators and defectors. As a general rule, we show that the lower the dilemma strength between sub-populations, the more abundant the cooperative strategy in the entire population. Results are confirmed by means of Monte Carlo simulations with pair approximation method, which reveals a rich plethora of novel and generally valid paths to cooperation.
Nanosized Iron Oxyhydroxide: Properties, Application, Preparation
Authors: Abuzarova Kamila , Korchuganova Olena
Published: June 2020

Nanoparticles are increasingly in demand in such rapidly developing types of human activity as microelectronics, catalysis, biosensors, etc. The mild neutralization process is desirable to obtain a high-quality product due to forming a great amount of nucleation centers. The advantage of carbamide application is its capability to dissolve in the reaction volume without interacting with it, and evenly distribute in volume, slowly hydrolyzing with ammonium ions formation. At the same time, a very mild neutralization regime is realized without local pH value excess. Method of iron oxyhydroxide obtaining by carbamide precipitation is illustrated below. The aim of investigation was to obtain nanoscale precipitate, to study the properties of the obtained material and to describe the precipitation process. The study of the iron (III) oxyhydroxide precipitation kinetics from the iron (III) sulphate solution, and a mathematical model of the process are presented in the article. A mathematical model of the precipitation process allows to take into account the influence of the substances concentration and the process temperature to the rate of precipitate production. The precipitate was characterized by X-ray and DTA analysis, as well as by Raman spectroscopy and scanning electron microscopy methods.
Supercapacitors as elements increasing the efficiency of photovoltaic installation
Authors: Rogowski Sz , Sibński M , Kolczyńska A , Kluba A
Published: June 2020

The main purpose of the research is to check an influence of supercapacitors as the elements increasing the efficiency of short-period energy storage in photovoltaic installations. Their task will be to substitute the batteries or enhance their performance as the energy bank. For the model storage setup consisting of six supercapacitors, the work charge-discharge characteristics were determined. Additionally, an influence of storage time on the amount of charge accumulated inside the battery was tested. Then the examined setup was coupled with a conventional PV module by the charge regulator system and tested in laboratory and under real operating conditions. Obtained results proved that the use of supercapacitors as buffer elements in energy storage system of photovoltaic installation can significantly increase operation lifetime and reliability.
Application of the local antimagic total labeling of graphs to optimise scheduling system for an expatriate assignment
Authors: Utami W , Wijaya K , Slamin
Published: June 2020

An expatriate assignment at the branch company in other country must be optimised due to the short term duty. Accuracy calculation is needed to optimise the expatriate assignment including its scheduling system. There are many ways and methods to optimise the scheduling system. One of the methods is making use of graph theory instruments such as local antimagic total labeling. The local antimagic total labeling of a graph is a map from the set of vertices and edges of the graph to the set of positive integers from 1 to the number of vertices and edges such that the weight of two adjacent vertices are different. The vertex weight is calculated by adding the labels of the vertex and all edges incident to it. In this paper, this labeling is applied to optimise the scheduling system for the expatriate assignment. This system can be modelled by a graph where the assignments are represented by vertices and connection between the assignments are represented by edges. The represented graph is then labelled by the local antimagic total labeling in order to obtain the minimum number of different vertex weights. The such number is equivalent to the optimal time allocated for the expatriate assignment.
The upper bound of vertex local antimagic edge labeling on graph operations
Authors: Agustin Ika Hesti , Dafik  , Marsidi  , Kurniawati E Y
Published: June 2020

Let G(V(G), E(G)) be a connected simple graph and let u, v be two vertices of graph G. A bijective function f from the edge set of G to the natural number up to the number of edges in G is called a vertex local antimagic edge labeling if for any two adjacent vertices v and v′, w(v) = w(v′), where

w
(
v
)
=

∑

e
∈
E
(
v
)

f
(
e
)

, and E(v) is the set of vertices which is incident to v. Thus any vertex local antimagic edge labeling induces a proper vertex coloring of G where the vertex v is assigned with the color w(v). The vertex local antimagic chromatic number χla
(G) is the minimum number of colors taken over all coloring induced by vertex local antimagic edge labeling of G. In this paper, we study the vertex local antimagic edge labeling of graphs and determine the upper bound of vertex local antimagic chromatic number on graph operation, namely cartesian product of graphs, corona product of graphs, and power graph.
Navigation and guidance control system of UNUSAITS AUV based on dynamical system using ensemble kalman filter square root
Authors: Herlambang T , Subchan  , Nurhadi H
Published: June 2020

This study presents the development of navigation system of AUV. It is initially in the form of a nonlinear system model to determine the trajectory for the AUV motion control. The non-linear system model of UNUSAITS AUV is then implemented in the Square Root Ensemble Kalman filter (SR-EnKF) to estimate the trajectory of the AUV. The developed EnKF algorithm covers two types of simulations. The contribution from this paper is trajectory or position estimation of nonlinear UNUSAITS AUV system with 6-DOF AUV model. The result of model estimation is presented based on numeric study and simulation. The first simulation is dedicated to generate 400 ensembles, and the second simulation is to generate 400 ensembles. The second simulation shows that the 500 ensembles give more accurate results. A further examination on the accuracy has been performed by accounting for the RMSE of actual condition and the estimation from the simulation, which yields the range of accuracy between 97 % up to 99%.
Profitability estimation of a Company in PT.ABCD using extended kalman filter
Authors: Anshori M Y , Herlambang T , Karya D F , Muhith A , Rasyid R A
Published: June 2020

Profitability ratios are the ability or results achieved by a company in its sales of goods or services it produces in a certain period. Profitability ratios are required to record financial transactions usually assessed by investors and creditors (banks) to assess the amount of investment profits to be obtained by investors and the amount of corporate profits to assess the company’s ability to pay debts to creditors based on the use level of assets and other resources so that the company efficiency can be seen. Profitability is an important factor in the company, so in this study estimation of company profitability is made. Profitability estimation in this paper used the Extended Kalman Filter (EKF) and Kalman Filter (KF)methods to obtain the accuracy of the estimation. Based on the analysis of the simulation results, the EKF and KF methods can be effectively implemented to estimate the profitability of a company so as to make the right policy in determining the amount of investment and company profits. Based on the results of the analysis on the simulation with 300, 400 and 500 iterations, it has an error of less than 2%.
The effect of lerak foam and kapok as a silencer on lightweight concrete
Authors: Nurtanto Dwi , Suyoso Hernu , Hasanuddin Ahmad , Hayati Zahra Hikmah , Mukhlisin
Published: June 2020

Lerak Foam is Foam produced by Lerak fruit mixed with water. This Foam is very suitable as an air cavity enhancer in lightweight concrete. Kapok is a natural material commonly used as pillows, mattresses and stuffed toys. Kapok with fine fibers and easily formed in a concrete mixture is expected to reduce noise. The purpose of this study is to reduce the noise of concrete materials by adding Lerak Foam and Kapok. This research was conducted in the Concrete Laboratory University of Jember, by making a sample of 40 cm x 40 cm x 40 cm concrete box with a thickness variation of 3 cm and 7 cm. This study intend to compare the value of noise reduction and transmission loss from the concrete specimen model with the addition of 100cc Lerak Foam and Kapok with 0%, 1.5%, 2.5%, 3.5% and 5% from the weight of concrete. The different values can be found by giving a noise gauge inside from the concrete box. The level of noise reduction is affected by the thickness of concrete. The level of noise reduction will increase as much as the addition of Kapok Fibers in concrete mixtures.
The comparison of exponentially weighted moving variance and double moving average-S control charts based on neoteric ranked set sampling
Authors: Putri R J M , Mashuri M , Irhamah
Published: June 2020

In manufacturing industry, quality is very important, because it can determine customers’ satisfaction and distinguish the product from others. The effort that can be made by companies to maintain the products quality is by monitoring and controlling them. One of the statistical methods that can be used for monitoring and controlling quality is control charts. Generally, there are two types of control charts, control chart for mean and control chart for variability. Three models of control charts, recently, have been developed, such as Shewhart, Cumulative Sum (CUSUM), and Exponentially Weighted Moving Average (EWMA). This research will be stated Exponentially Weighted Moving Variance (EWMV) and Double Moving Average-S (DMA-S) for monitoring variability based on Neoteric Ranked Set Sampling (NRSS). EWMV and DMA-S control charts can detect small shifts, and NRSS has better performance than Simple Random Sampling (SRS) and Ranked Set Sampling (RSS). Furthermore, the performance of EWMV based on NRSS and DMA-S basd on NRSS control charts will be compared and evaluated by using Average Run Length (ARL) value with Monte Carlo simulation approach to detect any particular shifts. Both of the control chart models will be applied in Combined Cycle Power Plant (CCPP) case. By this evaluation, the result shows that the DMA-S control chart based on NRSS performs better than the EWMV control chart based on NRSS.
Three form fourier series estimator semiparametric regression for longitudinal data
Authors: Kuzairi  , Miswanto  , Nyoman Budiantara I
Published: June 2020

Analysis of regressionis one technique that is often used in statistical analysis. There are three regression analysis approaches, such as parametric regression, nonparametric regression and semiparametric regression. Semiparametric regression consists of parametric components and nonparametric components. Parametric component that used such as linear estimator and nonparametric component by using a Fourier series estimator. Semiparametric regression approach that use Fourier series, have an advantages which is can resolve oscillation data pattern. This study compares the three Fourier series estimators such as sine, cosine, and combination between cosine and sine or complete estimator for longitudinal data. Longitudinal data can explain more complete information than cross section data or time series data. The purpose of this study is to introduce another Fourier series for the application of electricity consumption in Madura island. The results of this study indicated the optimal model in predicting electricity consumption in Madura island. The best estimator is the Fourier series estimator with the smallest Generalized Cross Validation (GCV) and Mean Square Error (MSE), and the biggest determination coefficient values by considering the parsimony of the model.
Analysis of factors affecting competition in bottled drinking water sales in Madura
Authors: Yulianto T , Fatmawati  , Windarto  , Rohmaniyah M , Faisol  , Mardianto M F F
Published: June 2020

Bottled Drinking Water is water that is treated using certain technologies, then packaged in various forms. The factors that influence the competition in the sale of bottled water include Branding, Packaging, Quality, Sales, Promotion, Competition, Brand, Price, Product Quality, Marketing. From this, there needs to be an analysis to determine the competition in selling bottled water between local and national products. Therefore, research will be conducted using the factor analysis method, factor analysis aims to identify the relationship between variables so that it can be classified into several sets of variables that are less than the number of initial variables. From the ten variables can be reduced to less after a factor analysis then of the ten variables into two factors, from each factor is given a group or name where the first factor is an influence factor and the second factor is an item factor. From each local product and national product have two factors, but of the two added together to produce diversity values, local products are able to provide a cumulative diversity value of 59.474%. While the National Product is able to provide a cumulative diversity value of 62.059%. This research contributed to the decision making regarding the factors that influence the competition in the sale of bottled water. This study provides recommendations to bottled water companies to give more attention to the factors that influence the success of bottled water sales.
Mathematics creativity skill of student in junior high school based on students thinking style
Authors: Isyrofinnisak F , Kusmayadi T A , Fitriana L
Published: June 2020

Mathematical creativity is the ability needed to solve various problems in mathematics. Each student has different creativity, one of which, influenced by thinking styles that have an impact on the quality of perception and ability to order. Students’ thinking styles are divided into four types, namely Concrete Sequential (CS), Abstract Sequential (AS), Concrete Random (CR), and Abstract Random (AR). This research is descriptive qualitative research. The research data were obtained from 25 junior high school students in the Kediri Regency with different student abilities and instruments used in the form of written tests and questionnaires and interviews. The results show that CS students can achieve creativity at the flexibility stage, AS students can achieve creativity at the fluency stage, CR students can reach creativity at the flexibility stage, and AR students can reach creativity at the novelty stage. In order to improve mathematical creativity, students should be given unlimited problem-solving in one way, and the teacher is expected to know students’ thinking styles to be able to determine the appropriate learning methods and techniques.
Scaffolding profile in solving geometry problems in terms of van Hiele level
Authors: Rahman H S , Susanto  , Hobri  , Irfan M , Karimah’ R , Albab A U
Published: June 2020

Solving the geometry problem is not an easy matter for some students. In addition to relying on understanding concepts, problem type exercises, scaffolding is also considered important to assist students in solving geometry problems. This study looked at the scaffolding process for students in solving geometry problems in terms of the van Hiele level. There are three groups of research subjects with each group of subjects representing students who have the ability of geometry at the visual, analytical, and informal deduction levels at the van Hiele level. The research method used is descriptive qualitative. Qualitative methods are used to analyze the subject scaffolding at each level of van Hiele in solving geometry problems. The results of the study found that subjects with a visual level tend to solve problems by presenting them in the form of images without observing in-depth the concepts used. So it takes scaffolding in terms of image presentation, mathematical concepts, and problem-solving flow. Subjects with the level of analysis identify the nature of the wake in the problem to determine the mathematical concepts used. Scaffolding is needed in the form of image presentation and problem-solving flow. While subjects with an informal level of deduction can determine the mathematical concepts used by first looking at the properties of the image. However, subjects at this level still need scaffolding in the problem-solving flow.
Student’s higher-order thinking skills on creative problem solving based on caring community
Authors: Lestari C F , Hobri  , Fatekurohman M , Lutvita D , Ningrum F Y W
Published: June 2020

The teaching and learning activities more effective and efficient if it is supported by high-quality learning device. This research aimed to develop the learning device by using Creative Problem Solving (CPS) based on caring community on "System of Linier Equations in Three Variables" and to determine its effect on student’s higher-order thinking skills. The type of study used is a mixed method that combines qualitative and quantitative method. Qualitative methods are used to obtain data related to the results of the development of learning tools and quantitative methods are used for statistical analysis. The subjects in this study were all students of class X in SMAN 1 Tegaldlimo, with samples consisting of 3 classes namely class X MIPA 1 as an experimental class 1 (with CPS), class X MIPA 2 as an experimental class 2 (with CPS based on caring community), and class X MIPA 4 as a control class (with conventional learning). Higher-order thinking skills were measured by using essay test. The data were analyzed by using normality, homogeneity and One-Way ANOVA tests using SPSS 19. The results of the study showed that (1) the learning device produced were valid, practical, and effective; (2) One-Way ANOVA test results obtained a sig. value of 0,000 < 0,05 which indicates that the implementation of learning device with CPS based on caring community had a significant effect on student’s higher order thinking skills.
Student’s higher order thinking skills on problem solving based on jumping tasks
Authors: Lutvita D , Hobri  , Pambudi D S , Lestari C F , Wahyuningrum F Y
Published: June 2020

Most of the students’ Higher Order Thinking Skills (henceforth, HOTS) are still weak in term of complex problem solving and thus to face this condition a research about problem solving learning by giving jumping tasks to the ninth grade students of junior high school under the subject Power of numbers and form of root is conducted to know their Higher Order Thinking Skills. This research employed mixed method combining Thiagarajan 4D model to develop the learning instruments and experimental research design to know the effect of the learning instruments implementation on the students Higher Order Thinking Skills. The students of SMPN 2 Balung were the subject of this research and three classes were chosen as the sample of the research consisting of two classes as the experimental class and one class as the control class. Learning material was not only developed to make the students able to solve problem but also provide jumping task exercises which designed for the students to solve problem in order to improve their Higher Order Thinking Skill. The research sample was given an essay test to measure their HOTS. The learning instruments developed fulfilled the criteria of valid, practical, and effective. The result of normality and homogeneity tests showed that the data were normally distributed and homogeneous, One-way ANOVA showed the value of sig. 0,000 (p<0,05) which can be concluded that the implementation of jumping task –based problem solving learning had significant positive effect on the students’ Higher Order Thinking Skill (HOTS)
The students’ mathematical reasoning ability based on problem based learning model
Authors: Sari M P , Susanto  , Yuliati N , Imamah E N , Laily N I
Published: June 2020

This research aimed to develop Mathematics instructional instruments by using problem based learning (PBL) on “straight line equation” Learning Material for the eightth grade of Secondary schools well as to know its effect on the students’ matematical reasoning ability. The method used is mixed methods with concurrent triangulation strategy model namely development research method with Thiagarajan model combined with quantitative method. The research subjects were the students of MTsN 5 Jember of Jember regency consisting of 31 students of trial class 31 of experimental class and 31 students of the control class. The instruments of this research are a observation, an test, and an interview. Quantitative method is applied to analyze the difference of student achievement result among two classes are experimental class and control class. while the qualitative method is applied to describe the process and results of problem-based learning development. The product of this study is the problem based learning teaching administrations. The validity of the average value of those teaching adsministrations (lesson plan, the students’ worksheet, THB) is 3,75. The research results showed that: (1) the instructional instruments resulted is valid, the implementa-tion of the instructional instruments is in practical and effective; (2) the significance value (2-tailed) is 0.000 (p < 0.05), which indicated that the application of learning by using PBL had a significant effect on the students’ matematical reasoning ability.
Student’s mathematical creative skill using interactive application media based on collaborative learning
Authors: Inawati P A , Hobri  , Pambudi D S , Guswanto E , Sya’roni A R
Published: June 2020

Completing Linear Equation System by Elementary Row Operations is a fairly complex problem in mathematics. Someone who is faced with this problem can be measured his creative skills. The fact shows that their creative skills are still relatively low. Therefore learning based collaborative using interactive application media will be applied. This research type was a mixed method, which combines quantitative and qualitative research. The Quantitative method is used to analyze student learning outcomes, while the qualitative methods is used to analyze students’ creative abilities. Respondents involved in this study consisted of three classes, consisting of two experimental classes and one control class which is each class consisting of 36 students. The objects of this research was the students of SMAN 1 Kencong Jember, who were selected three class as research samples, therefore XI MIPA 1 class as the first experimental class and XI MIPA 2 class as the second experimental class and at last XI MIPA 3 class as the control class. The research results indicated that the pre-test of three classes was homogeneous. While the post-test result shows that the average of the three classes is significantly different. This is indicated by the value of one way ANOVA (<p = 0.05), it was found that collaborative learning using interactive application media as part of the developed tool can provide better results in terms of creative thinking abilities. Interactive application media as part of collaborative-based learning tools can provide positive stimulation to students so that students’ creative thinking abilities increase. The tool developed in this study was also declared valid, practical and effective.
The analysis of research-based learning implementation and its affect to the students’ metacognition skill in solving a resolving domination number of a graph
Authors: Wangguway Y , Slamin  , Dafik  , Maylisa I N , Kurniawati S
Published: June 2020

Students are expected to be able to maximize metacognition skills by implementing research-based learning. This research aims to investigate the analysis of mathematics learning application implementation based on research-based learning and the influence on students’ metacognition skills in solving resolving domination number problems in the graph. The method used in the research is a mixed-method that is combining the qualitative and quantitative methods. The research subject is the 3rd-semester students consisting of 41 experimental class students and 31 control class students. Both classes are given different treatments. The instruments of this research are the test, observation, and interview. The qualitative method is used to analyze the difference between students’ learning result between two classes, while the qualitative method is applied to analyze students’ metacognition skills. The research results show that there is a significant difference between both classes implementing research-based learning and conventional learning model. The statistic result shows that the 2-tailed significance of independent sample t-test within the post-test is 0.000 or α ≤ 0.05. It shows that the implementation of research-based learning significantly affects students’ metacognition skills in solving resolving domination number problems. Based on the results of the portrait phase analysis, it is known that students in the experimental class have relatively good metacognition skills compared to the control class. This can be seen from the number of indicators that can be mastered by each student.