bluuebunny/crossref_metadata_2025 huggingface dataset:
The value of differentiated instruction in the inclusion of students with special needs/ disabilities in mainstream schools
Authors: Strogilos Vasilis
Published: January 2018

The aim of this presentation is to analyse the current international policies on inclusion and to discuss the value and use of differentiated instruction as a means to the inclusion of students with special needs/ disabilities in mainstream settings. The movement to inclusion requires teachers to create inclusive learning environments, which would encourage the use of practices that would benefit all students. In this respect, differentiated instruction has rapidly evolved as a teaching approach to meet the diverse and heterogeneous needs of students with special needs/ disabilities in mainstream classrooms. Modifying and adjusting instruction to allow all students in a classroom to access the general education curriculum is at the heart of inclusive education. In this presentation, I shall discuss the development of differentiated instruction as a means to inclusion for students with special needs/ disabilities in mainstream classrooms. Information will be provided with regard to the main principles of DI as well as the basic criteria in designing individualized adaptations for these students. In addition to this, I will review the factors which influence the development of differentiated instruction based on research findings. Finally, I will argue that differentiated instruction provides a learning environment which takes into consideration the individual characteristics of students and, as such, is a useful approach for the inclusion of students with special needs/ disabilities in mainstream settings.
Local Wisdom-Based Character Education In Teaching Balinese To Achieve National Integration Of a Nation
Authors: Kadek Mustika I
Published: January 2018

Indonesia, nowadays, still deals with complex problems, such as national disintegration and social disharmony of a nation. Many regions experience disunity which is started from smallest unit into larger unit. This problem will threaten the unity of Indonesia. It becomes a serious problem so that it is important to optimize the role of education which leads to the insertion of character education in early learning. Teacher is expected to be able to implement the character education, including the preparation, implementation, and evaluation. The implemented character education should be synergized to the local wisdom of each region because it has its own cultural values which could be guidances toward the attitude. Character education which is synergized with local wisdom aims at achieving the vision of integration and social harmony of a nation.
Bilingual instruction in early childhood education, can it better develop children?
Authors: Djahimo Santri E. P. , Indahri Yulia
Published: January 2018

This is a case study of teaching and learning using bilingual instruction in two schools of Early Childhood Education in Kupang-NTT, Indonesia. The aims of this study are to find out whether or not bilingual instruction in Early Childhood Education can better develop children (the outcomes) and if the issue of ‘the younger, the better” in children’s language acquisition in bilingual setting is acceptable and true. 4 students from one bilingual and one monolingual schools have been observed. In addition, parents and teachers of these students have also been interviewed. The data has then been analyzed qualitatively to come to the answers of the proposed questions, and the results reveal that bilingual instruction alone does not necessarily create better children unless it is supported by other factors, such as encouraging parents, professional teachers, and supporting environment. This is in a line with the findings of the issue about ‘the younger, the better’ in children’s language acquisition, that the younger does not always mean the better. Other aforementioned factors are needed in the development of children’s language acquisition. It’s recommended that all parties involved in children’s development can take part in developing their skills, knowledge as well as characters.
Constructing Self Awareness Using Education Human Value In School Culture
Authors: Wija Astawa Dewa Nyoman
Published: January 2018

The big number of poverty in Indonesia impact to the hope of having a free learning service, especially education for early age and elementary school students from the less fortunate families. Many people usually ask the quality of such kinds of free of charge schools. The low price makes a low standard for the students. Sathya Sai School in Denpasar has proven that the free learning service does not mean the standard quality of the school is low. This study will explain how the teachers and the members of the foundation build the awareness of the students and parents by socializing and internalizing the value that empower their collective awareness to help the school achievement. By using local cultural approach, the school builds a program that involves the parents especially the woman.
Reconstruction Of Character Values Based On Manggaraian Culture
Authors: Wahyu Yuliana , Leonangung Edu dan Ambros
Published: January 2018

This study aims at exploring and finding the character values in penti ceremony, Manggarai. Penti means the harvest thanksgiving ceremony of the Manggarai people. Penti is a sign of gratitude to God the Creator (Mori Jari Dedek) and to the ancestral spirits over all the crops. This research is conducted in East Manggarai district, NTT Province. There are several stages of ceremony penti, they are teinghang, barong lodok, barong wae, libur kilo, dan tiba meka landang. Each of these preparations with ritualistic rituals have their oun meanings. Technique of collecting data is done through interview and literature study. The research shows that penti emphasizes customs, imitation, exemplary, command, reward, and authority in character formation. Character formation is inseparable from the cultural environment in which children grow and develop.
Jolly phonics: effective strategy for enhancing children english literacy
Authors: Ariati Ni Putu Pebri , Padmadewi Ni Nyoman , Suarnajaya I Wayan
Published: January 2018

Having strong foundation in English literacy nowadays is believed to be a very crucial requirement for the children to survive and success both in educational and social lives. One of the most effective strategies for enhancing children’s early reading and literacy skill is through Jolly Phonics. Despite the popularity and its effectiveness, there is still factor to the absence of the strategy, namely lack of teacher knowledge. This paper is intended to share the techniques of how to implement Jolly Phonics strategy for teaching and developing children’s English literacy. This study was conducted in one of innovative bilingual schools in Denpasar, Bali. The study employed descriptive qualitative method as a research design and used observation, documentation and interview to collect the data from the teacher. The findings showed that the teacher had successfully implement the 5 skills in Jolly Phonics, namely (1) learning the letter sounds, (2) learning letter formation, (3) blending-for reading, (4) identifying sounds in words-for writing and (5) tricky words, through variety of enjoyable techniques involving children’s sight, sound and kinesthetic means. Thus, implementing Jolly Phonics through techniques explained will improve children’s overall English literacy skill.
Teacher’s Instructional Behaviour in Instructional Management at Elementary School Reviewed from Piaget’s Cognitive Development Theory
Authors: Eni Astuti Ni Putu
Published: January 2018

This writing aimed at (1) describing the importance of teacher to review instructional management at elementary school based on Piaget’s cognitive development theory; and (2) describing teacher’s instructional behavior in managing instructional at elementary school reviewed from Piaget’s cognitive development theory. In general, Piaget’ cognitive development theory divides children’ cognitive development into four stages. In the elementary school ages of 7 to 11 or 12 years old, Piaget classified the cognitive development into concrete operational marked by the use of clear and logic rules. The children implement logic thinking on concrete object, yet abstract or hypothetical. Although the intelligence of this step has been advanced, the way of thinking of the children is still limited because still based on concrete object. Therefore, teacher should comprehend the importance of concrete operational instructional at elementary school so the children could maximally achieve the learning goal in accordance to their thinking level that they acquire. The suggestion that can be proposed is that the teacher should synergize the characteristics of elementary school students in concrete operational stage with the instructional readiness in the steps of planning, implementation and evaluation.
The Use of Bilingual Methods through Scientific Approach at Integrated Subject to Improve the Student’s English Skills
Authors: Tur Rosidah Cholifah , Suryaman
Published: January 2018

This study was aimed to know the PGRI Adi Buana Surabaya primary teacher education program student’s English skill after being applied through scientific approach at integrated subject. Therefore, this study was conducted to support the student’s readiness in facing globalization era and international challenge, also created competent, superior, and high character. This study was an action research which conducted in two cycles. There were four steps namely planning, action, observation or evaluation and reflection. The subject of this study was 40 students of C class 2015. The data obtained was analyzed through descriptive analytic static. The result showed that there was 32, 74% enhancement of the student’s English skills after applied bilingual method through scientific approach. That enhancement could be seen on the average result of the cycle I which showed 47, 58% as a low category and increased to 80, 32% at cycle II as good category.
Third-Party Intervention in Asymmetric Conflict Resolution Pasar Raya Padang Post-Earthquake in 2009
Authors: Putra Ikhsan Muharma , Fitlayeni Rinel , Marleni  , Afrizal  , Indraddin
Published: January 2018

After earthquake 30 September 2009 Raya Market Padang began to be disturbed. Padang City Government responded quickly with construction of an emergency store, but has Opposed by some traders because decreased profits and low visitors. This condition triggered a long conflict and has been going on for five years (2009-2014). Many efforts have been made by stakeholders to find a conflict resolution, so it is important to further elaborate who actor has become a third party facilitating asymmetric conflict resolution. Based on the findings, the parties who really are in the position of a third party is the DPRD of Padang City and KOMNASHAM RI. The DPRD of Padang is structurally in the position of the government, but its function is as a representative of the people in the government. This position makes the slices between the DPRD and the traders as the people (constituents) and slices with Padang City Government as executive of the city government. The intervention undertaken by the DPRD was Hearing to Raya Market traders, and involving their representatives at the hearing, the DPRD working meeting discussing the issues related in 2ndCommission. Other interventions are controlling the rehabilitation and reconstruction process, and the realization of budgeting in APBD based on the needs of traders.
“GENIT” AS EFFECTIVE DESIGN OF LEARNING MEDIA
Authors: Supriadi Mardiki
Published: January 2018

There are two main approaches to using media in schools: students can learn "from" Media and technology, and they can learn "with" media and technology. The basis for The use of media and technology as a "tutor" in schools is "educational communication," that is the deliberate act of communicating content (teaching content) for students by assuming that they will learn something "from" this communication, so communication is not again free but controlled and conditioned for educational purposes. Findings on the impact of technologybased instruction in education can be concluded that technology as a tutor has a positive effect on learning, one of them is the student can complete a set of educational goals in less time than necessary in a traditional approach. However, these two approaches only make the task become easier but do not activate and facilitate them to think critical and higher learning. “Media Genit” uses a new approach as an approach that can optimize perspective-based cognitive processes, constructivism, which constitutes an environment in which the student as a designer thinks creative about content combined with real-world tasks, student learning content, enjoy the learning process, and recognize that they have created something that is valuable.
Teachers’ classroom assessment and grading practices
Authors: Widiastuti Ida Ayu Made Sri
Published: January 2018

This study was conducted to investigate the teachers’ classroom assessment and grading practices in Junior high schools in Bali. The participants of this study were professional junior high school teachers who were randomly selected as the sample of this study. In depth interviews and classroom observations were intensively conducted to the participants to collect the required data for the purpose of the present study. This study revealed that junior high school teachers made use of formative and summative assessment and employed several ways of grading practices. There were several factors affecting their classroom assessment and grading practices consisting of internal factors and external factors. The most prominent internal factor was the teacher's philosophy of teaching and learning and the main external factors were recognized as mandated statewide learning factors and high stakes tests, government polices, and parents. The findings indicated that junior high school teachers constantly make an effort to establish a reasonable balance between their teaching philosophy and the classroom environment reality. Thus it is recommended that junior high school teachers should review their assessment and grading practices and employ more appropriate assessment and grading practices.
Ecological Intelligence Level Of Hight School Students In Cimahi City
Authors: Mainaki Revi , Kastolani Wanjat , Setiawan Iwan
Published: January 2018

Indonesia is experiencing serious environmental problems as a negative impact of development. One of the areas that shows the problem of the environment is Cimahi City located in West Java Province. Therefore, efforts are needed to prepare future generations in order to have high ecological intelligence. The intelligence can be prepared and established through the process of education in the School. The purpose of this study is to measure the level of ecological intelligence of high school students in Cimahi City. This research uses survey method based on quantitative approach. The technique of determining the number of samples using stratified ramdom sampling and obtained 35 schools as sample. Data collection techniques used observation, interviews, questionnaires, literature studies and documentation studies. Data then analyzed and presented with descriptive statistic technique. The results showed that the level of ecological intelligence of learners varied between schools, from moderate to high levels. Judging from the components of ecological intelligence, the attitude aspect has the highest score followed by aspects of knowledge, skills and participation. All parties need to encourage schools and learners to improve ecological intelligence through various programs at schools based on environmental conservation efforts.
The Effect of the Instructional Media Based on Lecture Video and Slide Synchronization System on Statistics Learning Achievement
Authors: Partha Sindu I Gede , Yudhi Paramartha A.A. Gede
Published: January 2018

The purpose of this study was to determine the effect of the use of the instructional media based on lecture video and slide synchronization system on Statistics learning achievement of the students of PTI department . The benefit of this research is to help lecturers in the instructional process i to improve student's learning achievements that lead to better students’ learning outcomes. Students can use instructional media which is created from the lecture video and slide synchronization system to support more interactive self-learning activities. Students can conduct learning activities more efficiently and conductively because synchronized lecture video and slide can assist students in the learning process. The population of this research was all students of semester VI (six) majoring in Informatics Engineering Education. The sample of the research was the students of class VI B and VI D of the academic year 2016/2017. The type of research used in this study was quasi-experiment. The research design used was post test only with non equivalent control group design. The result of this research concluded that there was a significant influence in the application of learning media based on lectures video and slide synchronization system on statistics learning result on PTI department.
Development of science practicum performance assessment in junior high school
Authors: Riantini Ni Luh Rin , Suastra I Wayan , Budi Adnyana Putu
Published: January 2018

The purpose of this research was produce a performance science practicum assessment instruments based science process skill which is valid, reliable, practical, and effective for measuring the skill of science process in junior high school. The type of this research is development research designed with the assessment development model from Doran et al., 1998. The average result of the instrument validation test is 3.50 and can be categorized very valid and can be applied in the learning after going through several revisions. Reliability test results show that reliable instrument with reliability coefficient of 0.78. The average result of the instrument practicality test is 3.38 and it is practically categorized and can be applied in the learning after going through several revisions. From the average student score can be stated all students get the value above the minimal mastery criteria, with students the average score is 83.98 and from the t-test results obtained t count 30.376. Based on these findings, it can be concluded that the instrument assessment of science practicum performance based on science process skills can be used to measure students' science process skills, easy to use in learning, and effectively used in science learning activities.
The Effect of Value Clarification Technique (VCT) using Contextual Problem Content on Social Attitude and Social Science Learning Achievement of the Elementary School Students
Authors: Parmiti Desak Putu
Published: January 2018

This study analyzed and described changes in social attitude and social science learning achievement of the students who learn through value clarification technique (VCT) with contextual problem content and the students who learn through conventional teaching. This experiment or research was conducted at SD Gugus in Buleleng Regency with the population of 503 students. The number of sample for the experiment group was 40 students, and that for the control group was 40 too. The study used social attitude questionnaires and social study learning test to collect the data, while descriptive analysis and inferential analysis were used for analyzing the data. In this study, it was found (1) there was a significant difference in social attitude between the students who learned through VCT with contextual problem content and those who learned through conventional teaching, (Fobs.=6.370), (2) there was a significant different in learning achievement between the students who learned through VCT with contextual problem content and those who learned through conventional teaching, (Fobs.=4.040), and (3) there was a significant difference between social attitude and social science learning achievement simultaneously between the students who learned through VCT with contextual problem content and those who learned through conventional teaching. It means that the effect of teaching with VCT with contextual problem content in social science teaching produce a higher social attitude and social science learning achievement than the conventional teaching. Keywords: Value Clarification Technique (VCT), contextual problem, Social attitude, and learning achievement
Development Of Production Unit Model Based On Secondary High School Schoolprneneurship
Authors: Putra Pratama Galeh Nur Indriatno , Triyono Moch. Bruri
Published: January 2018

This study aims to determine: (1) weakness of vocational high school production unit; (2) model of production unit based on schoolpreneurship of vocational high school; and (3) the effectiveness of production unit model based on vocational high school schoolpreneurship. This research uses a R & D approach consisting of three stages: preliminary study, model development and model testing. The sample of this research is the production unit owned by Public Vocational High School (SMKN) 1 Depok, Public Vocational High School (SMKN) 2 Depok, Vocational High School (SMK) Muhammadiyah 3 Yogyakarta, and SMK Muhammadiyah Berbah. Data were collected using in-depth interviews and documentation. Result of research indicate that: (1) weakness of production unit so far is planning still monoton, job descriptions overlap, supervision not running maximal; (2) development of management model of vocational high school production unit as source of learning and alternative funding; (3) the test results indicate that 83.3% agreed that the model component is complete; 91.7% agreed that the structure of the model component was clear; 91.7% agreed that the relationship between model components is clear; 80% agreed that the model was feasible; and 82% agreed that the model is effective if implemented.
Elementary school students’ mathematical intelligence based on mathematics learning using classical music of the baroque era as the backsound
Authors: Karlimah
Published: January 2018

Many studies suggest that classical music can inccrease the listeners’ intelligence, including mathematical intelligence [3, 12, 2, 11]. In this research, we used the classical music of Baroque era as the backsound during math learning. The research method used was quasi experiment with nonequivalent pretest-posttest control group design to grade V SD students in Tasikmalaya city. The results show that the use of classical music of Baroque era during the learning of mathematics gave a high contribution to the mathematical intelligence of fifth grade elementary school students. The student's mathematical intelligence can be seen in the cognitive abilities which were at the high level in the knowledge up to analysis, and at the low level in the synthesis and evaluation. Low mathematical intelligence was shown by students in calculating amount and difference of time, and projecting word problem into the form of mathematical problems. High mathematical intelligence arose in reading and writing integers in words and numbers. Thus, the mathematical intelligence of fifth grade Elementary School students will be better if classical music of Baroque era is used as the backsound in mathematics learning about solving math problems.
The Development of Mathematics Comics Media on Linear Equations and Linear Inequalities of One Variable
Authors: Sepriyanti Nana , Tapia Cisil
Published: January 2018

This development research was aimed to produce mathematics comics media which valid and practical. This research was a research and development employing the 4-D model by Thiagarajan & Semmel (1974). The model consisted of four development stages, namely define, design, develop and disseminate. The research instruments were validation sheets and practicality sheets. The data were analyzed by grouping the data based on the product qualification. The calculations were made to obtain mean scores classified into categories in the Likert scale assessment. The validity of product can be seen from the result of experts validation which show that the product was valid (86.25%). The practicality of product can be seen from the result of the teacher and students practicality assessment sheet which show that the product was in a practical category (90.04%). Thus, it can be concluded that the mathematics comics media on linear equations and linear inequalities of one variable was valid and very practical to be used as a medium of learning in mathematics.
EFFECT OF USING PORTFOLIO ASSESSMENT TO IMPROVE SCIENTIFIC ATTITUDE OF STUDENTS LEARNING PHYSICS IN HIGH SCHOOL
Authors: Gede Wartawan Putu
Published: January 2018

This study aims to investigate the effect of portfolio assessment in teaching physics and scientific attitude. The research was conducted on students of high school in Singaraja. Research was an quasi- experimental study by using “The Posttest-Only Control Group Design”. The research involved 152 high school students of class X of science as samples, taken with multistage random sampling technique. Portfolio assessment was integrated with physics learning. The implementation of the portfolio assessment included four key elements such as the students' work folders, clear assessment criteria, and self-assessment, and conference between teacher and students. The data needed in this research was the students' scientific attitude which included the aspect of curiosity, respect for evidence, the willingness to change ideas, and critical reflection. Data needed in this research included scientific attitudes students. A Likert scale instrument was used to measure the scientific attitude students. Data were analyzed using analysis of variance with SPSS 20.0 at significance level α = 0.05. The results showed there are differences in the scientific attitude students who take physics learning with assessment portfolios and students who take physics learning with assessment of conventional. The findings of this study indicate that portfolio assessment in learning physics significantly affect the scientific attitude students.
SAW assisted domain wall motion in Co/Pt multilayers
Authors: Edrington Westin , Singh Uday , Dominguez Maya Abo , Alexander James Rehwaldt , Nepal Rabindra , Adenwalla S.
Published: January 2018

The motion of domain walls in thin ferromagnetic films is of both fundamental and technological interest. In particular, the ability to use drivers other than magnetic fields to control the positions of domain walls could be exciting for memory applications. Here, we show that high frequency dynamic strain produced by surface acoustic waves is an efficient driver of magnetic domain walls in ferromagnetic films with perpendicular anisotropy. A standing surface acoustic wave of resonant frequency 96.6 MHz increases the domain wall velocities in thin films of [Co/Pt]n by an order of magnitude compared to magnetic fields alone. This effect is highly resonant, effectively ruling out thermal effects, and the velocity shows distinct variations in the domain wall velocity at the nodes and antinodes of the standing wave. The data indicate that standing strain waves can drive the domain wall motion from the creep to the flow regime as the amplitude increases. Hence, strain waves could provide an alternative route to rapid domain wall motion.
Surface plasmon polaritons light radiation source with asymmetrical structure
Authors: Zhong Renbin , Yu Chengpeng , Hu Min , Liu Shenggang
Published: January 2018

An asymmetrical surface plasmon polaritons (SPPs) light radiation source with double metal films (SPLRD) is presented and studied. SPPs modes can be excited on the double metal films by a parallel traveling electron beam and then transformed into enhanced Cherenkov radiation in the substrate. Tunable dual-frequency radiation ranging from infrared to ultraviolet can be realized. In comparison with a single-metal-film structure, the efficiency, tunability, and output power density of the SPLRD are greatly increased, with up to eight times higher radiation power intensity being achievable. The radiation performance of a cylindrical SPLRD is enhanced to an even greater extent, with reductions in the required exciting electron-beam energy and the dielectric substrate permittivity. These novel properties due to the asymmetry of the structure and the SPPs excitation pattern are significant for furthering the understanding of electron beam–SPPs interaction and for the development of efficient wideband light radiation sources.
Effects of load variation and purge cycles on the efficiency of Polymer Electrolyte Membrane Fuel Cells for stationary applications
Authors: Santangelo Paolo E. , Tartarini Paolo
Published: January 2018

Polymer Electrolyte Membrane Fuel Cells have become rather popular for power generation; Dead-Ended Anode design is currently adopted to limit hydrogen consumption. However, gas and water accumulation at the anode outlet decrease stack performance, and so, purges are carried out to remove them. This work focuses on a Polymer Electrolyte Membrane Fuel Cell system featuring a voltage-drop-based purging strategy; 4 electric-load conditions (0.6–1.8 kW) were imposed to evaluate how purges impact the system performance as the applied load varies. Long-duration experimental tests were conducted at a constant load to reproduce cycles typical of stationary applications; various electric, thermal, and transport parameters were measured, and efficiency was ultimately determined. An analogy between increasing the applied load and increasing the cathode-air humidity level was found in terms of purge-related hydrogen losses and purge time. Stack current intensity is not affected remarkably by purging, whereas stack voltage exhibits higher oscillations at the higher loads and is less stable at the lowest one. A relationship is suggested between voltage, anode stoichiometry, and stack temperature, especially over the initial transient trend prior to reaching an approximately steady condition. Overall stack efficiency decreases as polarization losses increase along with the applied load; fuel efficiency is almost constant, even though slightly bigger at the higher loads, which implies that lower fractions of hydrogen are lost during purges. Net efficiency is relatively flat over the operative range, so this purging strategy tends to counterbalance the effects of polarization losses. However, power used to sustain auxiliaries shows a bigger impact than purge-related energy losses.
Magnetic tunnel junctions with an equiatomic quaternary CoFeMnSi Heusler alloy electrode
Authors: Bainsla Lakhan , Suzuki Kazuya Z. , Tsujikawa Masahito , Tsuchiura Hiroki , Shirai Masafumi , Mizukami Shigemi
Published: January 2018

Tunnel magnetoresistance (TMR) in MgO-based magnetic tunnel junctions (MTJs) with equiatomic quaternary CoFeMnSi Heusler and CoFe alloy electrodes is studied. The epitaxial MTJ stacking structures were prepared using ultrahigh-vacuum magnetron sputtering, where the CoFeMnSi electrode has a full B2 and partial L21 ordering crystal structure. Maximum TMR ratios of 101% and 521% were observed at room temperature and 10 K, respectively, for the MTJs. The large bias voltage dependence of the TMR ratio was also observed at low temperature (LT), as similarly observed in Co2MnSi Heusler alloy-based MTJs in the past. The physical origins of this relatively large TMR ratio at LT were discussed in terms of the half-metallicity of CoFeMnSi.
Parallel pumping of a ferromagnetic nanostripe: Confinement quantization and off-resonant driving
Authors: Yarbrough P. M. , Livesey K. L.
Published: January 2018

The parametric excitation of spin waves in a rectangular, ferromagnetic nanowire in the parallel pump configuration and with an applied field along the long axis of the wire is studied theoretically, using a semi-classical and semi-analytic Hamiltonian approach. We find that as a function of static applied field strength, there are jumps in the pump power needed to excite thermal spin waves. At these jumps, there is the possibility to non-resonantly excite spin waves near kz = 0. Spin waves with negative or positive group velocity and with different standing wave structures across the wire width can be excited by tuning the applied field. By using a magnetostatic Green's function that depends on both the nanowire's width and thickness—rather than just its aspect ratio—we also find that the threshold field strength varies considerably for nanowires with the same aspect ratio but of different sizes. Comparisons between different methods of calculations are made and the advantages and disadvantages of each are discussed.
Effect of grain boundaries on shock-induced phase transformation in iron bicrystals
Authors: Zhang Xueyang , Wang Kun , Zhu Wenjun , Chen Jun , Cai Mengqiu , Xiao Shifang , Deng Huiqiu , Hu Wangyu
Published: January 2018

Non-equilibrium molecular-dynamic simulations with a modified analytic embedded-atom model potential have been performed to investigate the effect of three kinds of grain boundaries (GBs) on the martensitic transformation in iron bicrystals with three different GBs under shock loadings. Our results show that the phase transition was influenced by the GBs. All three GBs provide a nucleation site for the α → ε transformation in samples shock-loaded with up = 0.5 km/s, and in particular, the elastic wave can induce the phase transformation at Σ3 ⟨110⟩ twist GB, which indicates that the phase transformation can occur at Σ3 ⟨110⟩ twist GB with a much lower pressure. The effect of GBs on the stress assisted transformation (SAT) mechanisms is discussed. All variants nucleating at the vicinity of these GBs meet the maximum strain work (MSW) criterion. Moreover, all of the variants with the MSW nucleate at Σ5 ⟨001⟩ twist GB and Σ3 ⟨110⟩ tilt GB, but only part of them nucleate at Σ3 ⟨110⟩ twist GB. This is because the coincident planes between both sides of the GB would affect the slip process, which is the second stage of the martensitic transformation and influences the selection of variant. We also find that the martensitic transformation at the front end of the bicrystals would give rise to stress attenuation in samples shock-loaded with up = 0.6 km/s, which makes the GBs seem to be unfavorable to the martensitic transformation. Our findings have the potential to affect the interface engineering and material design under high pressure conditions.
Synthesis and spectroscopic characterization of gold nanoparticles via plasma-liquid interaction technique
Authors: Khatoon N. , Yasin H. M. , Younus M. , Ahmed W. , Rehman N. U. , Zakaullah M. , Iqbal M. Zafar
Published: January 2018

Fabrication of non-functionalized gold nanoparticles is interesting owing to their potential applications in sensing and biomedicine. We report on the synthesis of surfactant-free gold nanoparticles (AuNPs) by Plasma-Liquid Interaction (PLI) technique, using micro-atmospheric pressure D.C. plasma. The effects of discharge parameters, such as discharge current, precursor concentration and gas flow rates on the structure and morphology of AuNPs have been investigated. Optical Emission Spectroscopy (OES) was employed to estimate the UV radiation intensity and OH radical density. Scanning electron microscopy (SEM) and ultraviolet-visible (UV-Vis) optical spectroscopy were employed to study the morphology and structure of AuNPs. The normalized intensities of UV radiation and OH radical density found to increase with increase in discharge current. We observed that the particle size can be tuned by controlling any of the following parameters: intensity of the UV radiation, OH radical density, and concentration of the Au precursor. Interestingly, we found that addition of 1% Ar in the feedstock gas results in formation of relatively uniform size distribution of nanoparticles. The surfactant-free AuNPs, due to their bare-surface, exhibit excellent surface-enhanced Raman scattering (SERS) properties. The SERS study of Rhodamine 6G using AuNPs as substrates, shows significant Raman enhancement and fluorescence quenching, which makes our technique a potentially powerful route to detection of trace amounts of dangerous explosives and other materials.
Detection of ultra-low oxygen concentration based on the fluorescence blinking dynamics of single molecules
Authors: Wu Ruixiang , Chen Ruiyun , Zhou Haitao , Qin Yaqiang , Zhang Guofeng , Qin Chengbing , Gao Yan , Gao Yajun , Xiao Liantuan , Jia Suotang
Published: January 2018

We present a sensitive method for detection of ultra-low oxygen concentrations based on the fluorescence blinking dynamics of single molecules. The relationship between the oxygen concentration and the fraction of time spent in the off-state, stemming from the population and depopulation of triplet states and radical cationic states, can be fitted with a two-site quenching model in the Stern-Volmer plot. The oxygen sensitivity is up to 43.42 kPa−1 in the oxygen partial pressure region as low as 0.01–0.25 kPa, which is seven times higher than that of the fluorescence intensity indicator. This method avoids the limitation of the sharp and non-ignorable fluctuations that occur during the measurement of fluorescence intensity, providing potential applications in the field of low oxygen-concentration monitoring in life science and industry.
Direct observation of magnetization reversal of hot-deformed Nd-Fe-B magnet
Authors: Zhu Xiaoyun , Tang Xu , Pei Ke , Tian Yue , Liu Jinjun , Xia Weixing , Zhang Jian , Liu J. Ping , Chen Renjie , Yan Aru
Published: January 2018

The dynamic magnetic domain structure in magnetization and demagnetization process of hot-deformed and NdCu-diffused Nd2Fe14B magnets were in-situ observed by Lorentz transmission electron microscopy (LTEM). The demagnetization process of hot-deformed sample is dominated by domain-wall pinning, while that of NdCu-diffused sample is mainly the magnetization reversal of single grains or grain aggregations. This firstly observed result gives an explicit evidence to understand the coercivity mechanism of magnetically segregated magnet. The effect of magnetic field of TEM on decrease in domain wall energy was theoretically analyzed, which helps to understand the in-situ observation process of magnetic materials.
Structure and dynamics of mica-confined films of [C10C1Pyrr][NTf2] ionic liquid
Authors: Freitas Adilson Alves de , Shimizu Karina , Smith Alexander M. , Perkin Susan , Canongia Lopes José Nuno
Published: January 2018

The structure of the ionic liquid 1-decyl-1-methylpyrrolidinium bis[(trifluoromethane)sulfonyl]imide, [C10C1Pyrr][NTf2], has been probed using Molecular Dynamics (MD) simulations. The simulations endeavour to model the behaviour of the ionic liquid in bulk isotropic conditions and also at interfaces and in confinement. The MD results have been confronted and validated with scattering and surface force experiments reported in the literature. The calculated structure factors, distribution functions, and density profiles were able to provide molecular and mechanistic insights into the properties of these long chain ionic liquids under different conditions, in particular those that lead to the formation of multi-layered ionic liquid films in confinement. Other properties inaccessible to experiment such as in-plane structures and relaxation rates within the films have also been analysed. Overall the work contributes structural and dynamic information relevant to many applications of ionic liquids with long alkyl chains, ranging from nanoparticle synthesis to lubrication.
In-depth study of in-trap high-resolution mass separation by transversal ion ejection from a multi-reflection time-of-flight device
Authors: Fischer Paul , Knauer Stefan , Marx Gerrit , Schweikhard Lutz
Published: January 2018

The recently introduced method of ion separation by transversal ejection of unwanted species in electrostatic ion-beam traps and multi-reflection time-of-flight devices has been further studied in detail. As this separation is performed during the ion storage itself, there is no need for additional external devices such as ion gates or traps for either pre- or postselection of the ions of interest. The ejection of unwanted contaminant ions is performed by appropriate pulses of the potentials of deflector electrodes. These segmented ring electrodes are located off-center in the trap, i.e., between one of the two ion mirrors and the central drift tube, which also serves as a potential lift for capturing incoming ions and axially ejecting ions of interest after their selection. The various parameters affecting the selection effectivity and resolving power are illustrated with tin-cluster measurements, where isotopologue ion species provide mass differences down to a single atomic mass unit at ion masses of several hundred. Symmetric deflection voltages of only 10 V were found sufficient for the transversal ejection of ion species with as few as three deflection pulses. The duty cycle, i.e., the pulse duration with respect to the period of ion revolution, has been varied, resulting in resolving powers of up to several tens of thousands for this selection technique.
Observation of coherent Smith-Purcell and transition radiation driven by single bunch and micro-bunched electron beams
Authors: Liang Yifan , Du Yingchao , Su Xiaolu , Wang Dan , Yan Lixin , Tian Qili , Zhou Zheng , Wang Dong , Huang Wenhui , Gai Wei , Tang Chuanxiang , Konoplev I. V. , Zhang H. , Doucas G.
Published: January 2018

Generation of coherent Smith-Purcell (cSPr) and transition/diffraction radiation using a single bunch or a pre-modulated relativistic electron beam is one of the growing research areas aiming at the development of radiation sources and beam diagnostics for accelerators. We report the results of comparative experimental studies of terahertz radiation generation by an electron bunch and micro-bunched electron beams and the spectral properties of the coherent transition and SP radiation. The properties of cSPr spectra are investigated and discussed, and excitations of the fundamental and second harmonics of cSPr and their dependence on the beam-grating separation are shown. The experimental and theoretical results are compared, and good agreement is demonstrated.
Precessional one-dimensional solitons in antiferromagnets with low dynamic symmetry
Authors: Galkina E. G. , Ovcharov R. V. , Ivanov B. A.
Published: January 2018

The nonlinear internal dynamics of one-dimensional topological magnetic solitons in antiferromagnets were studied theoretically, taking into consideration their real magnetic symmetry. The presence of the Dzyaloshinskii–Moriya interaction, which can lead to the appearance of weak non-collinearity of the antiferromagnet sublattices, results in a lowering in the dynamic symmetry of the magnet. As a consequence, there appear the effects of lowering the symmetry of the soliton with internal precession dynamics: precession of the spins becomes inhomogeneous in time and it is accompanied by oscillations of the soliton center. In a certain frequency range, the effects of short-wave magnon radiation are also possible.
Raman scattering study of the structural phase transition in single crystal KDy(MoO4)2
Authors: Peschanskii A. V.
Published: January 2018

Raman scattering of light in single-crystal KDy(MoO4)2 is studied at frequencies of 3–1000 cm−1 for temperatures ranging from 2 to 300 K, including that of a structural phase transition of the cooperative Jahn-Teller type (TC ∼ 14.5 K). During the transition to the low-temperature phase, a series of additional phonon lines corresponding to the Ag, B1g, B2g, and B3g modes is observed which indicates a doubling of the unit cell during the phase transition. An analysis of the symmetry of the phonon modes shows that the low-temperature phase has a predominantly monoclinic symmetry with conservation of a second order axis along the crystallographic b direction, i.e., perpendicular to the layers. Excitations are discovered which correspond to low-energy electronic transitions between levels of the ground-state 6H15/2 multiplet of the Dy3+ ion, which is split in the crystal field with a C2 symmetry. In the vicinity of the first excited Kramers doublet of the Dy3+ ion in crystalline KDy(MoO4)2, the scattered spectrum contains four lines [16.5, 21.0, 24.9, and 29.1 cm−1 (2 K)] at low temperatures, instead of a single line [18.3 cm−1 (25 K)] above the phase transition temperature (14.5 K). This indicates the existence of four nonequivalent dysprosium ions in the low-temperature phase.
Effect of surface protrusion on plasma sheath properties in atmospheric microdischarges
Authors: Fu Yangyang , Zhang Peng , Verboncoeur John P. , Christlieb Andrew J. , Wang Xinxin
Published: January 2018

The electric field enhancement due to the presence of cathode surface protrusion is investigated in atmospheric microdischarges with the goal of identifying the plasma sheath properties (such as cathode sheath thickness and electric field distortion). The electric field enhancement caused by surface protrusion is examined by adjusting the aspect ratio and the protrusion size. It is found that the cathode electric field enhancement depends strongly (weakly) on the aspect ratio (size) of the protrusion when it is much smaller than the discharge gap distance. In particular, the axial electric field in both vacuum and discharges becomes nonlinear with the protrusion on the cathode. The cathode sheath thicknesses obtained by two different methods are compared. With the same axial (or radial) protrusion dimension, increasing the aspect ratio will result in a significant decrease in the sheath thickness, whereas increasing the axial protrusion size with an unchanged aspect ratio will only lead to a slight decrease in the sheath thickness. The results contribute to predicting the relative plasma sheath properties from the geometrical parameter of the surface protrusion in atmospheric microdischarges.
Vibrationally resolved photoelectron spectra of lower diamondoids: A time-dependent approach
Authors: Xiong Tao , Włodarczyk Radosław , Gallandi Lukas , Körzdörfer Thomas , Saalfrank Peter
Published: January 2018

Vibrationally resolved lowest-energy bands of the photoelectron spectra (PES) of adamantane, diamantane, and urotropine were simulated by a time-dependent correlation function approach within the harmonic approximation. Geometries and normal modes for neutral and cationic molecules were obtained from B3LYP hybrid density functional theory (DFT). It is shown that the simulated spectra reproduce the experimentally observed vibrational finestructure (or its absence) quite well. Origins of the finestructure are discussed and related to recurrences of autocorrelation functions and dominant vibrations. Remaining quantitative and qualitative errors of the DFT-derived PES spectra refer to (i) an overall redshift by ∼0.5 eV and (ii) the absence of satellites in the high-energy region of the spectra. The former error is shown to be due to the neglect of many-body corrections to ordinary Kohn-Sham methods, while the latter has been argued to be due to electron-nuclear couplings beyond the Born-Oppenheimer approximation [Gali et al., Nat. Commun. 7, 11327 (2016)].