bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perspectives on exfoliated two-dimensional spintronics
Authors: Li Xiaoxi , Dong Baojuan , Sun Xingdan , Wang Hanwen , Yang Teng , Yu Guoqiang , Vitto Han Zheng 
Published: August 2019

Abstract
Magnetic orderings, i.e., the spontaneous alignment of electron spins below a critical temperature, have been playing key roles in modern science and technologies for both the wide applications of magnetic recording for information storage and the vibrant potential of solid state electronic spin devices (also known as spintronics) for logic operations. In the past decades, thanks to the development of thin film technologies, magnetic thin films via sputtering or epitaxial growth have made the spintronic devices possible at the industrial scale. Yet thinner materials at lower costs with more versatile functionalities are highly desirable for advancing future spintronics. Recently, van der Waals magnetic materials, a family of magnets that can in principle be exfoliated down to the monolayer limit, seem to have brought tremendous opportunities: new generation van der Waals spintronic devices can be seamlessly assembled with possible applications such as optoelectronics, flexible electronics, and etc. Moreover, those exfoliated spintronic devices can potentially be compatible with the famed metal-oxide field effect transistor architectures, allowing the harness of spin performances through the knob of an electrostatic field.
Functionals in stochastic thermodynamics: how to interpret stochastic integrals
Authors: Bo Stefano , Lim Soon Hoe , Eichhorn Ralf 
Published: August 2019

Abstract
In stochastic thermodynamics standard concepts from macroscopic thermodynamics, such as heat, work, and entropy production, are generalized to small fluctuating systems by defining them on a trajectory-wise level. In Langevin systems with continuous state-space such definitions involve stochastic integrals along system trajectories, whose specific values depend on the discretization rule used to evaluate them (i.e. the ‘interpretation’ of the noise terms in the integral). Via a systematic mathematical investigation of this apparent dilemma, we corroborate the widely used standard interpretation of heat- and work-like functionals as Stratonovich integrals. We furthermore recapitulate the anomalies that are known to occur for entropy production in the presence of temperature gradients.
Pyrolysis-GC/MS study of fast growing wood Macaranga gigantea
Authors: N Subagyono RR D J , Qi Y , Sanjaya A S , Amirta R , Chaffee A L 
Published: August 2019

Abstract
Py-GC/MS study on fast growing wood Macaranga gigantea at different temperatures has been conducted. The pyrolysis yields and chemical compounds obtained based on the pyrograms of the biomass by Py-GC analyses were compared with those obtained from batch pyrolysis experiments under similar conditions. Results show that the pyrolysis yields of Macaranga gigantea from Py-GC/MS analyses and batch reactor experiments at 300-450 °C were generally similar, ranging from 35 to 65%. Pyrolysis of the woody biomass with both techniques produced compounds which are mostly derived from pyrolysis, thermal degradation, or volatilization of lignin and cellulose/hemicellulose.
A review on photocatalytic: Modification of material and the application to removal of dye in wastewater
Authors: Wahyuniati R E , Hindryawati N , Wirawan T , Subagyono D J N , Panggabean A S 
Published: August 2019

Abstract
Photocatalytic materials have become a field of expansion in research, as evidenced by the many publication in science. With the many variation of semiconductors being tested as photocatalytic, it is necessary it with other materials or different semiconductor materials. Dealing with such an amount of information requires updated and educated guidance to select the most significant realizations. The state of the art photocatalysis with regard to materials and systems, considering the well-established results, but also the emerging aspect, and the envisaged new directions of this technology in the near future. In simulation and optimization of the photocatalytic reaktor model offer the last design. In addition, the opportunity for light source to be increase durability, relatively low cost and increase flexibility in the design and operation of future photocatalytic reactors.
Potential sulfate reducing bacteria for decrease Fe and Mn determination agents on ex-coal mining soil in Samarinda
Authors: Kusumawati Eko , Tri Widodo Nanang 
Published: August 2019

Abstract
The aim of this study was to determine the potential of sulfate reducing bacteria (SRB) as reducing agents for decrease Fe and Mn in acid soils of coal mines using five isolates of isolated SRB from post-coal mining sediments in Samarinda. The SRB potential test in reducing Fe and Mn was carried out by growing SRB on liquid Postgate media with varying pH of 3, 4 and 5 with the addition of mine acid soil to each treatment. Each of the pure SRB isolates (1 ml) was inoculated into liquid Postgate media with different pH, namely pH 3, 4 and 5 which had previously been filled with 5 grams of acidic soil after coal mining which had been mashed and sterilized at 121°C for 15 minutes. The culture was incubated in a threaded tube of 10 ml volume to full. The results showed that five isolates of SRB from post-coal mine sediments in Samarinda were Desulfococcus sp., Desulfotomaculum sp., Desulfobacter sp., Desulfobulbus sp. and Desulfobacterium sp. have potential as reducing agents for decrease Fe and Mn in Postgate B liquid media which have been added with coal mine acid soils. The best efficiency of Fe reduction by Desulfobacterium sp. at pH 3 is 6% and the best Mn reduction by bacteria Desulfotomaculum sp. at pH 5 is 4%.
Quorum quenching of Bacillus cereus INT1c against Pseudomonas syringae
Authors: Ananda Meryany , Rusmana I , Akhdiya A 
Published: August 2019

Abstract
Quorum Quenching is a process to prevent AHL signal accumulation resulting in the virulence factors and pathogenicity genes. The aims of this study were to determine the ability of the AHL (Acil Hocerine Lactone)-lactonase produced by Bacillus cereus INT1c and its potential as a biocontrol agent against Pseudomonas syringae. The experiments were swarming motility inhibition of P. syringae and inhibition assay of P. syringae on snap beans, INT1c produced extracellular and intracellular AHL-lactonase which could inactivate quorum sensing process of C. violaceum. The crude enzymes of INT1c were precipitated optimally at 70% saturation of ammonium sulphate. The Bacillus could reduce rot symptom of snap beans caused by P. syringae and motility of the pathogen. Swarming motility distance of the pathogen on control plates were 12.25 mm while the pathogen was co-cultured with INT1c was 3.3 mm. The average length of rot symptoms on positive control was longer (6.4 cm) than the snap beans inoculated with INT1c (3.92 cm). The population of P. syringae on the snap beans was decreased. Due to nutrient competition between P. syringae and INT1c. These results indicated that INT1c was potentially developed as a biocontrol agent.
Characterization of Phytophthora nicotianae fungi from Sulawesi cacao
Authors: Suwastika I N , Rifka  , Aisyah N , Rahmansyah  , Muslimin  , Ishizaki Y , Cruz A F , Basri Z , Shiina T 
Published: August 2019

Abstract
A pod rot disease caused by Phytophthora is one of serious treat on cacao farming system. This infection was reduced annual bean production remarkably (up to 30%). So far, there are seven species of this fungi were identified from the cacao farm over the world. However, we still lack of information on phytophthora properties from Sulawesi farm, which supplied more than 60% Indonesian cacao bean production annually. Here we report our result on isolation, identification, and characterization of these fungi from Sigi-Biromaru area (one of main farming area in Central Sulawesi). We showed that P. nicotianae could isolate from local infected pot. Bioassay on it infection rate was shown depend on the recictency of cacao clones/cultivars. This data suggesting that various species of Phytophthora exist in Sulawesi cacao farm, and its pathogenity was depend on the susceptibility of its clone of cacao.
Antioxidant activity of flavonoid constituents from the leaves of Macaranga tanarius
Authors: Marliana E , Ruga R , Hairani R , Tjahjandarie T S , Tanjung M 
Published: August 2019

Abstract
The beneficial health effect of natural flavonoids in plants is mainly because of their antioxidant properties. In the present study, antioxidant activity of isolated compounds from the leaves of Macaranga tanarius including nymphaeol C (1), solophenol D (2), nymphaeol A (3) and nymphaeol B (4) was conducted using 2,2-diphenyl-1-picrylhidrazyl (DPPH) method. The result showed that compound 2 revealed potential antioxidant activity followed by 1 and 4 with IC50 values of 55.13, 62.14 and 72.83 µM, respectively. While compound 3 showed antioxidant activity with IC50 value of 102.12 µM.
Antibacterial activity of flavan-3-ol derivative compound from dichloromethane extract of Artocarpus dasyphylla tree bark
Authors: Indriani Indriani , Harso Wahyu , Sosidi Husain 
Published: August 2019

Abstract
Infectious disease is one of sources of high morbidity and mortality caused by bacteria. Artocarpus plant is biosource to discover compounds with interesting bioactivites. The objective of this study is to find antibacterial compound from nature by extraction, fractionation, identification, and antibacterial test of secondary metabolite from dichloromethane extract of Artocarpus dasyphylla tree bark. The dichloromethane extract was fractionated repeatedly using various chromatographic techniques. The secondary metabolite was identified of its molecular structure based on UV-Vis, IR, NMR spectral data and confirmed by comparation with the reference. The secondary metabolite was known as catechin or 5,7,3’,4’-tetrahydroxyflavan-3β-ol. Antibacterial testing of cathecin against Escherechia coli and Staphylococcus aureus showed a low antibacterial activity.
Oil palm fruit ripeness detection using K-Nearest neighbour
Authors: Astuti I F , Nuryanto F D , Widagdo P P , Cahyadi D 
Published: August 2019

Abstract
Palm oil plant (Elaeis guineensis jacq) is one of the most popular plants in Indonesian plantation and also a species of the palm family. Harvesting process should obtain fresh fruit bunches at optimal ripeness. Some farmers are lack of ripeness knowledge and do not understand which color that represents optimal ripeness of palm fruit to harvest. Another issue on the scarcity of such system provides ripeness identification also encourage a study to develop an image-processing-based expert system. The aim of this study is to provide a tool for examining oil palm fruit ripeness level. Identification system consists of several image processing phases, namely image edge detection and feature value of the image to be calculated such as mean value, standard deviation, skewness, entropy, energy, homogeneity, contrast and intensity. In the proposed work, K-Nearest Neighbor (KNN) is applied as a computation method which allows the system to classify data of ripeness level based on user-entered image. The output is the identification of the ripeness level of the oil palm fruit.
Environmental quality index modeling in Indonesia using ordinal probit regression approach for panel data with random effect
Authors: Suliyanto  
Published: August 2019

Abstract
Environmental issues are one of the important global issues and are of concern because they are considered to require a solution. The Ministry of Environment and Forestry has developed an Environment Quality Index (EQI) that provides rapid information of an environmental condition with river water quality, air quality, and forest as indicator. This study aims to model EQI in Indonesia using ordinal probit regression for panel data with random effects. Parameter estimation of ordinal probit regression model for panel data with random effect using the marginal likelihood function, and maximize that function using M-point Gauss-Hermite Quadrature method. The data that be used in this study is EQI from 33 Provinces in Indonesia during 2011 to 2016 which are categorized into three category i.e less good, good and very good. The result of modelling is gotten variable that influence to EQI is Human Development Index (HDI). EQI opportunities in DKI Jakarta province in the year 2016 in the category of less good is high enough, that is equal to 99.89%. This may be due to high population density and less balanced with awareness of the population to preserve the environment. The accuracy of classification of modeling result is 70.202%.
Parameter estimation of mixed geographically weighted weibull regression model
Authors: Suyitno  , Sari N W W 
Published: August 2019

Abstract
This study discusses a Mixed Geographically Weighted Weibull Regression (MGWWR) Model. MGWWR is a regression model developed from a Geographically Weighted Weibull Regression (GWWR) model. Parameter estimation of GWWR model is done locally at every observation location using geographical location weighting. Based on parameter identification result in GWWR model, the certain covariates influencing the GWWR model may be global (the same value) in nature, whist others are different. Based on consideration this situation, a MGWWR model is proposed, in which some parameters are assumed to be constant and the others are different for every local model in the study area. The aim of this study is to identify the constant and local parameters in GWWR model, and to estimate the MGWWR model parameters using maximum likelihood estimation (MLE) method. Identification of constant and local parameters in GWWR model is initial step to construct the MGWWR model. The results show that test statistic for hypothesis testing on the constant parameter identification is Wilk’s statistic derived from likelihood ratio test (LRT) method, and the maximum likelihood estimator of MGWWR model can be obtained by using the Newton-Raphson iterative method based on the back-fitting procedure.
Forecasting index and stock returns by considering the effect of Indonesia pre-presidential election 2019 using ARIMAX and VARX approches
Authors: Ulyah S M 
Published: August 2019

Abstract
Election is a national event that can create significant impact on many sectors in a country. One of the affected sectors is finance. The upcoming Presidential election in Indonesia has two strong candidates who are rival since the late presidential election in 2014. The effect of this election is expected to have a big influence in the capital market, especially for Indonesian Index (IDX composite). Moreover, the stock owned by the candidate or the candidate relative is also expected to behave unusual. Therefore, this study aims to predict the return of those stock and index with the influence of Indonesia Pre-Presidential Election 2019. The stock of interest is the stock of PT. Saratoga Investama Sedaya Tbk (SRTG). The method used in study is defined into two categories. The index and stock are analyzed individually by univariate method—Autoregressive Integrated Moving Average with Exogenous variable. Multivariate method is also conducted to examine the relation among these stock and index. The used approach is Vector Autoregressive with Exogenous variable. The exogenous variable in this study is the dummy variable of Indonesia pre-Presidential Election. The results show that pre-election vibe does not significantly affect the return of the index and stock.
The impact of teaching style and FCI gain on the performance in mechanics tests
Authors: Azzopardi C , Camilleri L , Bonello C 
Published: August 2019

Abstract
The purpose of this study is to identify the relationship, if any, between the gain in the force concept inventory (FCI) and study level, gender, repeaters/non-repeaters, teaching style and the end-of-year mechanics result. The study focussed on all students (N = 395) admitted to a post-secondary institution in Malta in October 2015 and who participated in the pretest and posttest FCI exercise, studying physics at advanced (N = 162) or intermediate level (N = 233). There were 36 students at advanced level and 44 students at intermediate level who did not participate in the posttest FCI. In this study a multiple-choice test was used comprising of 30 questions about mechanics concepts and a questionnaire (by Centre for Occupational Research and Development (CORD)) was given to the lecturers to identify the teaching goals and methods used. The pretest was given on the second week of the academic year, October 2015, so that their response was not influenced by mechanics teaching and the posttest (identical to pretest) was given in the end of the scholastic year, May 2016. The results of the study suggest that only 13.7% of the participants exceeded the average-expected gain of 24%. The gain is higher for males, for participants studying advanced level physics and for participants who were taught by particular lecturers with particular teaching goals and methods. There is a positive correlation between the gain in the FCI and the end-of-year score in mechanics questions about forces and Newton’s laws of motion.
Using students’ learning to improve teaching: the case of the cream rising to the top
Authors: Borg Marks Joan 
Published: August 2019

Abstract
Teachers go to class to teach their students. One may question how often teachers use students’ visualisation of a concept to probe students’ understanding and to improve their own teaching. This paper focuses on the link between analogical reasoning and mental modelling in the teaching of electric circuits. A study conducted with 17-year-old physics students of different ability is described. From the results of a pre-test, post-test and semi-structured interviews using an ‘analogy prompt’, it will be shown how, when learning is meaningful, analogy generation can be developed and modified easily by students to relate the analogue to the target in question, thus providing evidence of the existence of scientific models of concepts in the minds of the students. It will be argued that the teaching of abstract concepts may be improved by using analogies indicated by high ability/gifted students who manage to develop a scientific view of concepts in question.
3D-printable height models for dc circuits
Authors: Bodensiek O , Sonntag D A , Glawe I , Müller R 
Published: August 2019

Abstract
We present an approach to learn about electricity and dc electric circuits by using real representational models based on the gravitational analogy. The additively manufactured models are deployed in a small-scale teaching intervention on electric potential and voltage in simple electric circuits. From the preliminary results considerable learning gains can be inferred.
Learning how to teach experiments in the school physics laboratory
Authors: Gkioka O 
Published: August 2019

Abstract
The focus of this research is in the broader area of physics teacher education. The aim is to investigate physics teachers’ efforts to learn how to teach and assess experiments, and in particular, concepts related to scientific evidence in the school physics laboratory. The study has looked at the participants as both learners and prospective teachers. It has taken place within the context of the course “Secondary Science Lab Applications” within a pre-service teacher education program in a Department of Secondary Science and Mathematics Education. Twenty-four students participated. The participants: a) revised the main concepts related to scientific practices (in particular, experimental validity and reliability of measurement), b) developed lesson plans, teaching and assessment methods and, c) taught school physics experiments. Interviews were conducted with the participants during their preparation for teaching and after teaching. They were observed when teaching and all classes were videotaped. A qualitative and quantitative data analysis identified particular trends among the participants. Students’ difficulties while they designed, carried out experiments and wrote lab reports were identified, as well as the difficulties they experienced when teaching experiments.
Active-learning settings and physics lectures: a performance analysis
Authors: Schiltz G , Feldman G , Vaterlaus A 
Published: August 2019

Abstract
We have divided a non-physics undergraduate student cohort into two parallel teaching settings. We offered a highly interactive flipped class (SCALE-UP) to one group of 52 students and a reformed LECTURE to the remaining 318 students. We compared student performance in both settings, based on a common midterm exam. The SCALE-UP students performed significantly better on conceptual problems, but for numerical problems, SCALE-UP and LECTURE students showed similar results.
Magnetic phenomena and living systems in the bio area degrees
Authors: Caltun O , Michelini M , Stefanel A 
Published: August 2019

Abstract
An educational path was designed aiming to improve the comprehension of basic concepts of magnetism of students of the Bio areas and developing a functional understanding of these concepts applied in the specific context of study and their work profession. A pilot study at the University of Udine involved students of agro-food degrees to analyse how they considered magnetic concepts and their use in their own area of study. In the final examination, they were requested to exemplify and to discuss in which contexts of their own area of study magnetic phenomena are involved. The students identified a wide spectrum of contexts in which magnetic concepts can be actualized at four different scales: astronomical/planetary, human/animal, cellular and atomic/nuclear. In the majority of cases, they showed competencies in using concepts like magnetic field and interaction to discuss in context examples in their own areas of study. Some difficulties in distinguishing magnetic effects from electrostatic effects emerged, as well as the need to be conscious of the strength, complexity and role of magnetic phenomena involving different scale levels at the same time.
The knowledge of Hungarian students in the light of the Mechanics Baseline Test
Authors: Kádár C , Tasnádi P 
Published: August 2019

Abstract
In the introductory courses in physics at Loránd Eötvös University (ELTE) students with very different physics knowledge can be found. The core problem appears to be undeveloped thinking skills and deficiency in conceptual understanding. Investigation of conceptual understanding is not simple, however, there are some reliable instruments for it such as the Mechanics Baseline Test which was constructed by Hestenes and Wells. In this paper the results of this test obtained in Hungary (mainly at ELTE) are presented. The test is universal in the sense that it is limited to the concepts that should be addressed in introductory physics at any level from secondary schools to universities. In 2016 at the Faculty of Science of ELTE students enrolled in introductory physics courses were tested. The students’ majors were Biology, Earth Sciences, Physics and Physics Teaching. The same test was given as a post test for the students of Physics and Earth Sciences. The results were compared to those of obtained previously in Hungarian secondary schools, at ELTE courses and at the universities in the USA (Arizona State University, Harvard University). It can be stated that at ELTE the test scores of the students of physics major has decreased significantly in the last 20 years. (Maybe it is the consequence of the implementation of Bologna Process due to which the number of the students entering into the University highly increased.) It was also revealed that there are difficult topics in kinematics and dynamics the understanding of which shows serious deficiencies at any level. (For example the dynamics of the curvilinear motion.) Finally on the basis of the results a proposal for the improvement of the instruction strategy is presented.