bluuebunny/crossref_metadata_2025 huggingface dataset:
Lead geometry and transport statistics in molecular junctions
Authors: Ridley Michael , Gull Emanuel , Cohen Guy
Published: June 2019

We present a numerically exact study of charge transport and its fluctuations through a molecular junction driven out of equilibrium by a bias voltage, using the inchworm quantum Monte Carlo method. After showing how the technique can be used to address any lead geometry, we concentrate on one dimensional chains as an example. The finite bandwidth of the leads is shown to affect transport properties in ways that cannot be fully captured by quantum master equations: in particular, we reveal an interaction-induced broadening of transport channels that is visible at all voltages and show how fluctuations of the current are a more sensitive probe of this effect than the mean current.
Cubic-quintic nonlinear Helmholtz equation: Modulational instability, chirped elliptic and solitary waves
Authors: Tamilselvan K. , Kanna T. , Govindarajan A.
Published: June 2019

We study the formation and propagation of chirped elliptic and solitary waves in the cubic-quintic nonlinear Helmholtz equation. This system describes nonparaxial pulse propagation in a planar waveguide with Kerr-like and quintic nonlinearities along with spatial dispersion originating from the nonparaxial effect that becomes dominant when the conventional slowly varying envelope approximation fails. We first carry out the modulational instability (MI) analysis of a plane wave in this system by employing the linear stability analysis and investigate the influence of different physical parameters on the MI gain spectra. In particular, we show that the nonparaxial parameter suppresses the conventional MI gain spectrum and also leads to a nontrivial monotonic increase in the gain spectrum near the tails of the conventional MI band, a qualitatively distinct behavior from the standard nonlinear Schrödinger system. We then study the MI dynamics by direct numerical simulations, which demonstrate the production of ultrashort nonparaxial pulse trains with internal oscillations and slight distortions at the wings. Following the MI dynamics, we obtain exact elliptic and solitary wave solutions using the integration method by considering physically interesting chirped traveling wave ansatz. In particular, we show that the system features intriguing chirped antidark, bright, gray, and dark solitary waves depending upon the nature of nonlinearities. We also show that the chirping is inversely proportional to the intensity of the optical wave. In particular, the bright and dark solitary waves exhibit unusual chirping behavior, which will have applications in the nonlinear pulse compression process.
Optical signatures of pentacene in soft rare-gas environments
Authors: Stauffert Oliver , Izadnia Sharareh , Stienkemeier Frank , Walter Michael
Published: June 2019

Acenes and pentacene (Pc), in particular, are promising candidates for organic dyes with interesting properties important for solar light to energy conversion. We present a combined experimental and computational study of Pc in an ultracold environment that allows for high resolution optical spectroscopy. The spectra and their vibrational substructure are interpreted with the help of density functional theory calculations. While there are only slight changes within superfluid helium as compared to vacuum, the neon surface shows more prominent effects. Additional vibrational coupling by neon modes leads to broadening as well as the emergence of new features, like the otherwise symmetry forbidden out-of-plane butterfly mode.
Generation of a strong reverse shock wave in the interaction of a high-contrast high-intensity femtosecond laser pulse with a silicon target
Authors: Jana Kamalesh , Lad Amit D. , Shaikh Moniruzzaman , Kumar V. Rakesh , Sarkar Deep , Ved Yash M. , Pasley John , Robinson Alex P. L. , Kumar G. Ravindra
Published: June 2019

We present ultrafast pump-probe reflectivity and Doppler spectrometry of a silicon target at relativistic laser intensity. We observe an unexpected rise in reflectivity to a peak approximately ∼9 ps after the main pulse interaction with the target. This occurs after the reflectivity has fallen off from the initially high “plasma-mirror” phase. Simultaneously measured time-dependent Doppler shift data show an increase in the blue shift at the same time. Numerical simulations show that the aforementioned trends in the experimental measurements correspond to a strong shock wave propagating back toward the laser. The relativistic laser-plasma interaction indirectly heats the cool-dense (ne≥1023 cm−3 and Te∼10 eV) target material adjacent to the corona, by hot electron induced return current heating, raising its temperature to around 150 eV and causing it to explode violently. The increase in reflectivity is caused by the transient steepening of the plasma density gradient at the probe critical surface due to this explosive behavior.
Extraction of eight-band k⋅p parameters from empirical pseudopotentials for GeSn
Authors: Liu Shao-Qi , Yen Shun-Tung
Published: June 2019

We extract the parameters for the eight-band k⋅p model for Ge1−xSnx (x≤0.15) from the calculation of the nonlocal empirical pseudopotential method with the modified virtual crystal approximation. The atomic pseudopotential form factors of Ge are improved such that the calculated Ge band structure has the commonly accepted bandgap and effective masses. The improved Ge parameters are used in proper interpolation to derive the parameters of GeSn for empirical pseudopotential calculation. The calculated band structures suggest that the Ge1−xSnx alloys exhibit a transition between an indirect bandgap semiconductor and a direct one at Sn composition xc=0.071. From the calculation, we extract the bandgap, the split-off energy, the interband momentum matrix element, and the effective masses of Ge1−xSnx (x≤0.15) as functions of x. From these results, we further derive the parameters used in the eight-band k⋅p model. These parameters are well expressed in quadratic form. The k⋅p model with the extracted parameters can give an interband tunneling current in a “pin” diode that is consistent with the current calculated by the empirical pseudopotential method.
Feasibility of a high stable PbTe:In semiconductor for thermoelectric energy applications
Authors: Parashchuk T. , Dashevsky Z. , Wojciechowski K.
Published: June 2019

High-efficiency thermoelectric conversion is achieved by using materials with a maximum figure of merit Z = S2σ/κ, where S is the Seebeck coefficient, and σ and κ are the electrical conductivity and thermal conductivity, respectively, over a wide temperature range. Lead telluride alloys were some of the first materials investigated and commercialized for generators; however, their full potential for thermoelectrics has only recently been revealed to be greater than commonly believed. The maximal value of Z, as a function of electron density, is attained only for a specific location of the Fermi level EF relative to the conduction band edge EC. A systematic study of structural, microstructural, and thermoelectric properties of bulk PbTe doped with indium is presented. Samples were prepared by the pulsed electric current sintering technique. The high dimensionless figure of merit ZT ≈ 0.8 over 200–500 °C temperature range for PbTe doped with 0.05–0.1 at. % of In was obtained. Moreover, ZT is practically the same for Pb0.9995In0.0005Te and Pb0.99In0.01Te compounds at high temperature. Therefore, indium dopant in PbTe stabilizes the optimal location of the Fermi level. The effect of the negative process of indium diffusion into the matrix during the long service time of the TE generator could be avoided by doping heavily with indium the hot side of n-type functionally graded PbTe:In leg.
Graphite to diamond transformation under shock compression: Role of orientational order
Authors: Volz Travis J. , Gupta Y. M.
Published: June 2019

To gain insight into the role of orientational order on the shock-induced graphite to diamond phase transformation, three pyrolytic graphite types having different orientational orders were shock-compressed along the average c-axis to peak stresses between 35 and 69 GPa. The materials studied were ZYB-grade highly oriented pyrolytic graphite (HOPG), ZYH-grade HOPG, and as-deposited pyrolytic graphite (PG) having mosaic spreads of 0.8° ± 0.2°, 3.5° ± 1.5°, and ∼45°, respectively. Wave profiles, obtained using laser interferometry, show a multiple-wave structure with a distinct, rapid (<10 ns) rise to the high-pressure phase for each graphite type. Multiple-wave profiles, first observed in this study for the less ordered ZYH-grade HOPG and PG samples, show that somewhat poorly oriented pyrolytic graphites also undergo a well-defined phase transformation. Previously, rapid transformation was reported for ZYB-grade but not ZYH-grade HOPG. The measured wave profiles for both HOPG grades are very similar and both grades show a ∼22 GPa transformation stress. In contrast, the PG wave profiles are quite different and show a ∼46 GPa transformation stress. The continuum results (stress-density states) presented here cannot distinguish between the different high-pressure phases [hexagonal diamond (HD) or cubic diamond] reported in recent x-ray studies. Because ZYB-grade HOPG was recently shown to transform to HD and due to the similar peak states for both HOPG grades, it seems likely that ZYH-grade also transforms into HD. The very different shock responses of PG and HOPG suggest different transformation mechanisms for PG and HOPG, but the high-pressure PG phase remains unclear in the present work.
Unique approach optimizes electroaerodynamic propulsion
Authors: Kish Stacy W.
Published: June 2019

By decoupling ion production and acceleration, researchers bring electroaerodynamic propulsion one step closer to reality.
Smooth solutions of the eikonal equation and the behaviour of local minima of the distance function
Authors: Tsar’kov I. G.
Published: June 2019

We study smooth solutions of the eikonal equation. To do this, we investigate the problem of geometric-topological properties of the singularities of the distance function and the regular set. We establish a connection between the caustic and domains where the number of local minima of the distance function is constant. We pose a number of problems about reflecting surfaces bringing light to a single point (a focus) and introduce the notions of generalized ellipsoids and paraboloids.
Integrable geodesic flows on orientable two-dimensional surfaces and topological billiards
Authors: (Fokicheva) V. V. Vedyushkina , Fomenko A. T.
Published: June 2019

The authors have recently introduced the class of topological billiards. Topological billiards are glued from elementary planar billiard sheets (bounded by arcs of confocal quadrics) along intervals of their boundaries. It turns out that the integrability of the elementary billiards implies that of the topological billiards. We show that all classical linearly and quadratically integrable geodesic flows on tori and spheres are Liouville equivalent to appropriate topological billiards. Moreover, the linear and quadratic integrals of the geodesic flows reduce to a single canonical linear integral and a single canonical quadratic integral on the billiard. These results are obtained within the framework of the Fomenko–Zieschang theory of the classification of integrable systems.
Emeritus Professor Reinhard Ferdinand Mathias Van Steveninck (1928–2017) and Dr Margaret Elva Van Steveninck (1931–2017) – plant physiologists and electron microscope X-ray microprobe specialists
Authors: Price Terence V.
Published: June 2019

This obituary highlights the careers and contributions of two eminent plant physiologists. Emeritus Professor Reinhard Van Steveninck (1928–2017) was educated at Wageningen and London University. He joined the Department of Scientific and Industrial Research (DSIR), New Zealand, and achieved early recognition for his publications on abscission and mechanisms of salt uptake of plants. He was appointed Professor of Agriculture (Plant/Soil Science) at La Trobe University in 1976. He expanded his research into salinity tolerance of lupins and the ultrastructural localisation of ions using X-ray microprobe analysis. He was a good teacher and nurtured and trained many researchers in this area. He was a recognised expert in using a combination of ultrastructural techniques to study the movement of ions within plant cells and across tissues. His publications include book chapters on plant physiology, as well as a major review on the ‘washing’ or ‘ageing’ phenomenon in plant tissues. He was an active member and President of the Australian Society of Plant Physiologists. Margaret Van Steveninck (1931–2017) worked as a Research Assistant at Adelaide University and subsequently as a Demonstrator and Senior Demonstrator in Botany at Queensland and La Trobe University. Her plant physiology research with her husband resulted in numerous joint publications including a chapter on microanalysis in ‘Electron microscopy of plant cells’.
Mate choice explains high genetic diversity in a small founding population of the New Zealand sea lion (Phocarctos hookeri)
Authors: Foote Imogen , Godfrey Stephanie S. , Robertson Bruce C.
Published: June 2019

Founder populations are susceptible to reduced genetic diversity, which can hinder successful population establishment. A new genetic lineage of the New Zealand sea lion (Phocarctos hookeri) has recently colonised the historical range of the New Zealand mainland (Otago Peninsula). Despite a small founding population, previous research indicated that nuclear genetic diversity in the Otago Peninsula population is similar to that of the larger source population (Sandy Bay, Auckland Islands). Our research aimed to identify whether mechanisms of female mate choice could help to explain the unexpectedly high level of genetic diversity in the founder population. We used genetic data at 12 microsatellite loci for mother–pup pairs from both populations, and the software COLONY to identify putative paternal genotypes inferred from allele sharing between known mother–pup pairs. We found that mating pairs were, on average, more related at the Otago Peninsula location. However, Sandy Bay females were mating with males more related to themselves than expected by chance, while the Otago Peninsula females were not. These findings suggest that female choice in this otariid species appears important, although may be constrained in some situations. Our findings also help to explain how the recently founded population is able to maintain a viable, growing population.
Discovery of endoplasmic reticulum calcium stabilizers to rescue ER-stressed podocytes in nephrotic syndrome
Authors: Park Sun-Ji , Kim Yeawon , Yang Shyh-Ming , Henderson Mark J. , Yang Wei , Lindahl Maria , Urano Fumihiko , Chen Ying Maggie
Published: June 2019

Significance

Podocyte injury is the hallmark of nephrotic syndrome (NS), a leading cause of chronic kidney disease affecting approximately 500 million people. We demonstrate that the podocyte endoplasmic reticulum (ER) calcium release channel, type 2 ryanodine receptor (RyR2), undergoes phosphorylation during ER stress. The accelerated podocyte ER calcium efflux due to leaky RyR2 activates cytosolic protease calpain 2, leading to podocyte injury. Most importantly, we have identified a chemical compound, K201, and a biotherapeutic protein, MANF, that can fix leaky RyR2 and inhibit podocyte injury. In addition, K201 can attenuate proteinuria in a podocyte ER stress-induced NS mouse model. The new class of drugs, podocyte ER calcium channel stabilizers, is an emerging therapeutic strategy to treat NS caused by ER dysfunction.
An interoceptive illusion of effort induced by false heart-rate feedback
Authors: Iodice Pierpaolo , Porciello Giuseppina , Bufalari Ilaria , Barca Laura , Pezzulo Giovanni
Published: June 2019

Significance

To ensure our survival, the brain continuously estimates important homeostatic and physiological variables, such as our hunger, thirst, and effort levels. This estimate relies on multiple signals, most prominently on interoceptive signals coming from inside the body (e.g., cardiac and respiratory signals). Here we tested the hypothesis that providing false feedback about these signals produces an interoceptive illusion, that is a misperception of one’s own physiological state. We show that giving participants false (faster) acoustic feedback about their heartbeats during an effortful cycling task induced the illusion of making more effort. Rather, participants did not report lower effort when slower acoustic feedback was provided, suggesting that the brain considers the potential costs of underestimating effort and fatigue levels.
Dissecting fat-tailed fluctuations in the cytoskeleton with active micropost arrays
Authors: Shi Yu , Porter Christopher L. , Crocker John C. , Reich Daniel H.
Published: June 2019

Significance

The cytoskeleton is a remarkable example of an active biomaterial and is at the heart of critically important problems in biology and medicine related to animal cells’ mechanical sensing and function. A satisfying physical understanding of the actomyosin cortex’s complex biophysics and mechanical properties has, however, proven elusive. We measure cytoskeletal motion, forces, and rheology using substrates containing arrays of flexible microscopic posts with high precision and statistical power. Surprisingly, the cytoskeletal networks display highly intermittent fluctuations whose energy content is dominated by rare large events, similar to what is seen in earthquakes or physical systems with avalanches. Our findings suggest that future cytoskeletal models must contain elements that self-organize onto a mechanically marginal state prone to avalanches.
Arabinogalactan protein–rare earth element complexes activate plant endocytosis
Authors: Wang Lihong , Cheng Mengzhu , Yang Qing , Li Jigang , Wang Xiang , Zhou Qing , Nagawa Shingo , Xia Binxin , Xu Tongda , Huang Rongfeng , He Jingfang , Li Changjiang , Fu Ying , Liu Ying , Bao Jianchun , Wei Haiyan , Li Hui , Tan Li , Gu Zhenhong , Xia Ao , Huang Xiaohua , Yang Zhenbiao , Deng Xing Wang
Published: June 2019

Significance

Due to the vital role for eukaryotes, clathrin-mediated endocytosis (CME) has attracted increasing attention, but great challenges still stand. Here, by overcoming the biggest challenge in CME research, we visualized the dynamic of extracellular cargo receptor protein by using stimulated emission depletion microscopy. We identified an unconventional mechanism for extracellular cargoes, here specifically rare earth elements (REEs). We showed that arabinogalactan proteins (AGPs) act as extracellular cargo receptors and move across the plasma membrane to initiate endocytosis. REEs promote the cross-membrane translocation of its extracellular cargo receptor AGPs to activate their endocytosis. Our data thus provide insights into the mechanism for the activation of CME, the biological role of AGPs, and the cellular mechanisms of REE actions in plants.
The hominid ilium is shaped by a synapomorphic growth mechanism that is unique within primates
Authors: Zirkle Dexter , Lovejoy C. Owen
Published: June 2019

Significance

The human ilium is unusually short and broad compared with those of all other primates. Its specialized shape facilitates pelvic control during upright walking. Our ilium also exhibits a unique developmental feature: Its anterior inferior spine forms via a secondary center of ossification. We surveyed iliac development in a wide range of fetal to adult nonhuman primates, and found that such specialized anterior inferior spine formation is unique to humans and our known ancestors. Because this derived iliac structure facilitates upright walking, its presence serves as a direct indicator of the adoption of terrestrial bipedality in the fossil record and as an indicator of the minimum age of that adoption.
Structural basis for adenylation and thioester bond formation in the ubiquitin E1
Authors: Hann Zachary S. , Ji Cheng , Olsen Shaun K. , Lu Xuequan , Lux Michaelyn C. , Tan Derek S. , Lima Christopher D.
Published: June 2019

The ubiquitin (Ub) and Ub-like (Ubl) protein-conjugation cascade is initiated by E1 enzymes that catalyze Ub/Ubl activation through C-terminal adenylation, thioester bond formation with an E1 catalytic cysteine, and thioester bond transfer to Ub/Ubl E2 conjugating enzymes. Each of these reactions is accompanied by conformational changes of the E1 domain that contains the catalytic cysteine (Cys domain). Open conformations of the Cys domain are associated with adenylation and thioester transfer to E2s, while a closed conformation is associated with pyrophosphate release and thioester bond formation. Several structures are available for Ub E1s, but none has been reported in the open state before pyrophosphate release or in the closed state. Here, we describe the structures ofSchizosaccharomyces pombeUb E1 in these two states, captured using semisynthetic Ub probes. In the first, with a Ub-adenylate mimetic (Ub-AMSN) bound, the E1 is in an open conformation before release of pyrophosphate. In the second, with a Ub-vinylsulfonamide (Ub-AVSN) bound covalently to the catalytic cysteine, the E1 is in a closed conformation required for thioester bond formation. These structures provide further insight into Ub E1 adenylation and thioester bond formation. Conformational changes that accompany Cys-domain rotation are conserved for SUMO and Ub E1s, but changes in Ub E1 involve additional surfaces as mutational and biochemical analysis of residues within these surfaces alter Ub E1 activities.
Oral corrective feedback on written errors
Authors: Afshari Sajad , Dabaghi Azizollah , Ketabi Saeed
Published: June 2019

The current study investigated the differential effect of two types of oral feedback – graduated oral corrective feedback (GOCF) in accordance with sociocultural theory (SCT) and supplemented direct oral corrective feedback (SDOCF) in accordance with cognitive-interactionist theory (CIT) – on Iranian pre-intermediate EFL learners’ written errors. The study used a pretest-treatment-immediate posttest-delayed posttest design with three groups. Two types of tests were employed to measure the learners’ explicit and implicit knowledge of English articles. The results of the repeated measures mixed-design ANOVAs and post-hoc analyses demonstrated that while both types of feedback significantly improved both types of knowledge in the immediate posttest, a clear advantage was found for the GOCF in the long term. The findings indicate that oral feedback, especially the GOCF within SCT, could be an effective means of addressing learners’ written errors and improving their implicit knowledge.
Incidental vocabulary learning through viewing television
Authors: Rodgers Michael P. H. , Webb Stuart
Published: June 2019

Previous research investigating L2 incidental vocabulary learning from video has primarily focused on short videos from genres that may be conducive to vocabulary learning. The research provides evidence that L2 incidental vocabulary learning can occur through video. However, it is uncertain whether viewing episodes of full-length television programs can contribute to incidental learning. This study investigated the effects of viewing 7+ hours of television on incidental vocabulary learning as well as the effects of the frequency and range. One-hundred and eighty-seven Japanese university students viewed ten 42-minute episodes of an American drama. Two vocabulary tests at differing sensitivities were used in a pre- and post-test design measuring receptive knowledge of the form-meaning connection of 60 word-families. The results indicated that (a) viewing television contributed to significant gains in vocabulary knowledge and (b) there was a positive relationship between frequency of occurrence and vocabulary learning. Pedagogical implications are discussed in detail.
Investigation of atomic and electronic properties of 2D-MoS2/3D-GaN mixed-dimensional heterostructures
Authors: Sung Dongchul , Min Kyung-Ah , Hong Suklyun
Published: June 2019

We have performed density functional theory calculations to study the effects caused by the interfacial structure between 2D-MoS2 and 3D-GaN. Two different surface terminations of GaN are considered: Ga-terminated (0001) (Ga-GaN) and N-terminated (

000

1
¯

) (N-GaN) configurations. We confirm that Rashba spin splitting occurs in band structure of MoS2 on GaN. We also find that the surface states of GaN move to the deep position in band structure in the MoS2/Ga-GaN case, while the surface states of GaN are hybridized with MoS2 near the Fermi level for the MoS2/N-GaN case. Furthermore, we investigate the variation in electronic structure of MoS2/GaN heterostructures depending on the number of MoS2 layers. Especially, the top layer MoS2 of the 2L-MoS2/GaN structures shows both n-type and p-type properties depending on the GaN surface termination. As a result, we suggest that the electrical characteristics of the 2D/3D heterostructures could be controlled by the surface terminations of substrate materials.
Selective area intermixing of III–V quantum-dot lasers grown on silicon with two wavelength lasing emissions
Authors: Liao Mengya , Li Wei , Tang Mingchu , Li Ang , Chen Siming , Seeds Alwyn , Liu Huiyun
Published: June 2019

The ability to tailor the bandgap of III–V compound semiconductors spatially, across the wafer is highly desirable for monolithically integrating photonic components with multi-functions. Using rapid thermal annealing with SiO2 and TiO2 capping layers as a selective area intermixing technique, we have demonstrated selective area bandgap tuning of III–V quantum dot (QD) material on a silicon (Si) substrate. Electrically pumped InAs/GaAs QD lasers directly grown on Si with dual-wavelength lasing emissions of 1275 and 1313 nm have been fabricated by this technique. This result indicates that the selective area intermixing technique can potentially be used in optical integrated circuits for Si photonics.
Power-efficient piezoelectric fatigue measurement using long-range wireless sensor networks
Authors: Rodenas-Herráiz David , Xu Xiaomin , Fidler Paul R A , Soga Kenichi
Published: June 2019

In this paper we describe the design of a proof-of-concept wireless embedded sensor system for continuous strain cycle monitoring as a method for fatigue life assessment on civil structures. Monitoring of strain cycles is energy demanding, and therefore not suited to energy-constrained devices, as it requires continuous acquisition of strain data with a high sampling rate, followed by data processing using algorithms for peak-trough detection and cycle counting. To overcome this drawback, at the core of our proposed design is a piezoelectric-based analogue sensor system that can achieve as much as a factor of 9 increase in energy efficiency compared with the conventional approach. The key component is an analogue peak-trough detector that offloads the computation in peak-trough detection from the microcontroller, thus eliminating the need for continuous sampling. The function of the detector is coupled with an energy-efficient interrupt-driven software design for acquisition and strain cycles calculation, which is carried out by using a standard form of the rainflow cycle counting algorithm. For wireless communication and networking, LoRa and LoRaWAN are adopted as core modules. We illustrate the performance of our proposed solution by way of simulation and laboratory experiments. Results show a good agreement in measurement of strain cycles between our proposed system and the conventional approach. Thus, our solution proves to be promising for real fatigue measurement applications.
Quantum shell effects in the hydrodynamic equations of a quantum fluid
Authors: Kuratov S E , Shidlovski D S , Menshov I S , Blinnikov S I
Published: June 2019

Numerical analysis of the hydrostatic equilibrium of a compressed gas bubble was carried out by the DFT method. Based on this analysis, we modified the hydrodynamic equations of a quantum fluid taking into account quantum shell effects. An external force acting on the electronic subsystem is added to the modified hydrodynamic equations. A numerical algorithm for solving of the system of modified hydrodynamic equations is discussed.
Diffusion of light through a disordered ensemble of resonant Mie-particles embedded in a medium with circular dichroism
Authors: Gorodnichev E E , Rogozkin D B
Published: June 2019

We study transmission of unpolarized light (incoherent superposition of right-hand circular and left-hand circular polarized waves) through an optically active medium doped by scattering Mie-particles. The medium is assumed to possess circular dichroism. Within the spatial diffusion approximation, the degree of circular polarization of the transmitted radiation is calculated. It is shown, that in the presence of scatterers a significant increase in the circular polarization compared to the medium with no scatterers can be observed.
Production of carbon nanofibers by plasma jet of helium and hydrocarbons
Authors: Shavelkina M B , Amirov R Kh , Kiselev V I , Katarzhis V A
Published: June 2019

The parameters of a non-catalytic process for synthesizing carbon nanostructures during the conversion of methane / helium and propane-butane / helium jets have been studied. The spectral features of the radiation of mixed systems have been investigated. Analysis of the spectra showed that the main part of carbon dimers is withdrawn from the hot region of the plasma in the outlet plasma stream. Synthesized products were been characterized by scanning electron microscopy, Raman spectroscopy, thermal analysis and X-ray photoelectron spectroscopy. It is shown that carbon nanostructures have a bamboo-like morphology and similar properties when using both methane and propane-butane mixture as a carbon source. It has been established that the morphology of synthesized carbon nanofibers is not affected by the pressure of the medium.
Interaction of corona discharge with surface layer of metal
Authors: Kirko D L , Savjolov A S
Published: June 2019

Properties of the corona discharge containing a conic electrode were researched. The main modes and characteristics of this discharge were researched. There are current oscillations of the discharge within the range of 1 kHz - 150 MHz. Possible oscillation and wave processes are considered to explain these oscillations. Emergence of rotation motion when the discharge affects the dielectrics is being studied. The effect of this discharge on metal surface was explored.
Silicon and germanium nanostructures formed by spark discharge plasma
Authors: Yakunin V G , Presnov D E , Stepikhova M V , Yablonskiy A N , Assilbaeva R B , Grevtseva T Yu , Zhanabaev Z Zh , Savinov V P , Timoshenko V Yu
Published: June 2019

Formation of semiconductor nanostructures on the surface of single crystalline silicon and germanium wafers by spark discharge plasma in air was investigated. The prepared nanostructures were analyzed by means of the scanning and transmission electron microscopy and optical spectroscopy of the photoluminescence and Raman scattering. The formed nanostructures exhibit a fractal-like morphology with interconnected nanocrystals of 2-200 nm sizes that is explained by repeated processes of spark ablation and subsequent condensation. While the size and morphology of the nanostructure depend on power sources of the spark discharge, short interaction times of spark discharge plasma and target determine a relatively low efficiency of the chemical oxidation of germanium and silicon, as well as low ionic temperatures of the plasma.
Development of the equipment of beam channels for applied and biomedical research at the NICA complex
Authors: Baldin A A , Vishnevskiy A V , Laktionov K K , Panacik V A , Tyutyunnikov S I , Yudin D I , Yudin I P
Published: June 2019

The report deals with the construction of the ion beam transport line for applied and biomedical research at the NICA accelerator complex, JINR, Dubna. Calculations of the beam output channels from the Nuclotron and Booster are carried out. The used electronics is described. We also discuss the compilation and realization of the plan of treating a tumor located at a depth up to 30 cm.
Numerical simulation of longitudinal and transversal electron dynamics in classical microtron
Authors: Bashmakov Y A , Dyubkov V S , Lozeev Y Y
Published: June 2019

Numerical simulation of 3D electron dynamics in classical Lebedev institute microtron with energy 6-10 MeV is carried out. Special attention is paid to particles transversal motion investigation. A comparison of physical electric field distribution along cavity axis with that obtained by means numerical calculation is done. The obtained results are discussed.
Data Mining Technique as Majors Support System Management with Classification Approach
Authors: Basri  , Siddiq Muhammad , Tamin Rosmawati , Azis Sulihin
Published: June 2019

Majors systems in an educational institution both at the primary level and higher education are the main thing. The academic potential of students becomes one of the main factors in supporting the success of learning. Even in an admission system, entrance test cannot be separated from the potential academic test. The academic potential test is only used as a standard of acceptance, and very rarely even never used to be information that can classify students into a specialization. Analysis of potential academic data with various variables will be very much so that required Data Mining techniques to mining of the larger data. The purpose of this research is to implement of Data Mining technique with classification approach to analyze academic potency in the major supports system management. The classification technique is applied as the object of research and measured its performance to obtain information according to the needs and objectives of the study. The results showed that the implementation of classification techniques could provide information that indicates the academic potential in major support system management, so this research can be a reference to create a system of potential academic search in general and can be implemented as an applicable tool in major support system management.
Measuring Village Head Performance using Fuzzy TOPSIS Method
Authors: Sahabuddin Chuduriah , Basri  , Muslihudin Muhammad , Latifah Nurul , Irawan Dedi
Published: June 2019

The village head is the leader of the village in Indonesia. The village head is the leader of the village government. The tenure of the village head is six years, and can be extended for another one term is expected to run the government with a good performance in providing services to the community. So if the government officials at the village level show good performance in organizing the government. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method can help decision making in determining the performance index of the village head. This research is conduct by looking for the performance of positive and negative ideal solutions. Applications with the highest V value will occupy the top size in this system. Then the criteria for determining the performance index of the head of the village are timeliness, discipline, responsibility, leadership, presence, value. The results of the decision-making system resulted in 6 alternatives suggested performance indexes of village heads, with the highest score of Sendang Agung Village.
A Website Framework to Support the Distribution of Milkfish in The Fishing Industry
Authors: Qashlim Akhmad , Basri  , Haeruddin  , Nurtanio Ingrid , Ilham Amil Ahmad
Published: June 2019

Delivering milkfish pond products to industries, restaurants or end consumers should be done as soon as possible in real time so that the process of milkfish distribution does not take a long time. The middleman’s involvement in the distribution process will require a lot of time and lots of people so that it dramatically affects marketing and price fluctuations. This research has found a solution to minimize the situation that occurs, a website framework with a supply chain concept approach successfully designed. A website with an integrated system can be accessed with an android mobile device to facilitate the process of uploading images of milkfish and other information about milkfish so that it does not require users to use personal computers (PC/laptop), while computer administrators can control the activities of pond farmers in marketing. The results showed that the website was able to connect between fish farmers and industries or restaurants before the results of the milkfish ponds were harvested and provide information about fish weight, fish prices, the location of lakes and order facilities for purchase transactions. If this happens, the middleman’s involvement in marketing begins to decrease, and this will undoubtedly cut the chain of the dependence of the farmer farmers with intermediaries. This is a way to accelerate the marketing process, and increase the income of fish farmers and reduce dependence on intermediaries.
Distribution and Abundance of Plankton in The Downstream of Jeneberang River
Authors: Lodang Hamka , Kurnia Nani
Published: June 2019

This study aimed to investigate the distribution and abundance of plankton in the downstream area of Jeneberang River. A total of three observation stations were chosen through purposive sampling method on a watershed in the downstream area, which lies between Gowa Twin Bridge and Barombong Bridge, Takalar Regency, and Makassar City. At each station, a sample was taken from the northern (N) and southern (S) part of the river. The collected sample of Plankton was observed using a binocular light microscope and Sedgwick Rafter Counting Cell (SRCC), and then subjected to the identification by using plankton identification book. The result of data analysis showed that phytoplankton and zooplankton could be found in all observation stations, but the abundance and distribution of each group differed one another. Phytoplankton group with the highest to the lowest abundance is the member of Class Chlorophyceae, Bacillariophyceae, and Dinophyceae. Meanwhile, the commonly found zooplankton is the member of Protozoa, including Paramecium sp., Chilomonas sp. Besides that, the member of Animalia, including annelid larvae and polychaeta larvae were also found with a lower level of abundance.
Selected Dicots That can Easily be Sectioned using Hand - Section Method and can Provide Good Anatomical Appearance: For Beginners
Authors: Kurnia Nani , Azis Andi Asmawati , Adnan  , Tri Lestari G.
Published: June 2019

This research was conducted to find out the type of dicotyledon which its stem can be sectioned with the method of hand section (HS) and can provide clear anatomy appearances. Research activities start with (1) section using the HS method, (2) observation using a microscope, and the last is (3) limited trial. For the first stage, it was determined that 10 cosmopolitan dicotyledonous found around Universitas Negeri Makassar campus. The stems of all the plants were sectioned by the HS method. The result is 5 of 10 species of dicots were categorized as easy to slash by HS method, namely Ixora maxima, Eclipta prostate, Mirabilis jalapa, Catharanthus roseus and Acalypha siamensis. In the second stage, the five plant species were sections and observed with a microscope. Based on observations using the monocular XSP-12 light microscope adjusted by Optilab Professional Edition, it can be seen that there are 4 plant species that provide the good anatomical appearance that is E. prostate, M. jalapa, C. roseus, and A. siamensis. For the last stage, all four types of plants that provide a good cross-section of the stem anatomy were tested to final semester students and new students. Both groups tried on sectioning and observing and gave their opinion on the level of difficulties. The answer shows that the majority of the groups consider that sectioning and observing of the four dicots are easy or very easy. To sum up, dicots E. prostate, M. jalapa, C. roseus, and A. siamensis are easy to section by HS method and to observe by microscope.
Properties of Concrete Blocks Made from Sugar Mill Waste
Authors: Taufieq Nur Anny Suryaningsih , Pertiwi Nurlita , Ahmad Irma Aswani
Published: June 2019

This research is an experimental study of the properties of concrete blocks made from sugar mill waste. The properties that are reviewed are weight, water absorption, and compressive strength. The concrete blocks were made with five treatments for sand substitution with sugar mill waste (SMW) which were controls B0 (0%), B1 (6.25%), B2 (12.5%), B3 (18.75%) and B4 (25%) with a ratio of cement water of 0.4. Each treatment group was 30 samples so that the total sample was 150. The results showed that a high percentage of SMW caused a decrease in the weight of the blocks and increased water absorption. The addition of SMW on the aggregate affects the compressive strength of the blocks. A high percentage of SMW causes a decrease in the compressive strength of concrete blocks. The results of the statistical analysis showed that the addition of 12.5% SMW (B2) had an effect on the weight and absorption of the blocks, while the change in the compressive strength of the concrete block occurred with the addition of 6.25% SMW (B1).
Structure of The Treelets and Shrub Vegetation in Tropical Sub-Mountain Forest of Mount Salak Bogor, West Jawa, Indonesia
Authors: Wiharto Muhammad , Wijaya Muhammad , Kusmana Cecep , Prasetyo Lilik Budi , Partomiharjo Tukirin
Published: June 2019

We study the structure, indicator species and diversity of treelets and shrubs vegetation in tropical sub-mountain forests of Mount Salak Bogor, West Java. There were 4 vegetation groups at Bray-Curtis distance 0.6 - 0.8, namely groups 1, 2, 3, and 4, each consist of 13 plots, 17 plots, 8 plots, and 22 plots. One way Permanova test shows that the vegetation group is different in terms of structure and composition of vegetation. Dicranopteris dichotoma (Thunb.) Bernh., Athyrium sorzogonense (Presl.) Milde., and Cinchona officinalis L., are the species with the highest Important Value Index in all plots. Indicator species are not found in group 2. There are 8 combined vegetation groups that have indicator species. The one-way Kruskal-Wallis test shows the difference in Shannon-Wienner diversity index (H’) (Kruskal-Wallis χ2 = 20.541, df = 3, p-value = 0.0001311 ), Simpson’s index (D) (Kruskal-Wallis χ2 = 23.855, df = 3, p-value = 2.678e-05), Pielou’s evenness index (J’) (Kruskal-Wallis χ2 = 14.315, df = 3, p-value = 0.002506) and Species Richness (S) (Kruskal-Wallis χ2 = 17.868, df = 3, p-value = 0.0004683) among vegetation groups. Post hoc test with Games Howel shows group 2 and 4 have differences in all parameters of diversity. The values of H’, D, and S between group 1 and 4 are different. The difference in S values also appears between group 3 and 4.
Isolation and Characterization of Azotobacter from Neems Rhizosphere
Authors: Hala Yusminah , Ali Alimuddin
Published: June 2019

Nitrogen-fixing bacteria can be isolated from rhizosphere plants, and one of the N2-fixing bacteria is Azotobacter. One of the plants that can grow well in dry and barren soil conditions is Neem (Azadirachta indica A. Juss)(Mimba). The purpose of this study was to determined any Azotobacter isolated from the rhizosphere of the neem plant. The type of research is an experimental study, tracing the diversity of Azotobacter in the rhizosphere of the neem plant. The study was conducted by taking soil samples from the rhizosphere of neem plants on the Bali Island. Morphological characterization based on colony observation in terms of shape, color, margin, and texture. The isolated cells were determined based on Gram staining and determination of the presence of spores. Isolates were characterized by various biochemical methods namely nitrate, reductase, citrate utilization, methyl red, VP test, catalase (method of slip-cover), and oxidase tests. The soil sample was taken from rhizospheres of 5 plants. The results showed that the N2-fixing bacteria isolated in the five soil samples were Azotobacter paspali and Azotobacter vinelandii (Azomonas) groups. Actinomycetes were found when isolating using specific media Azotobacter on plant 2.
Development of Green Banana Cake (Pisang ijo) Products using Kelor Leaf (Moringa oleifera Lam) as a Food Dye and Flour Substitute
Authors: Nahriana  , Yahya Muhammad , Tawani Ratnawati
Published: June 2019

Pisang ijo is one of the traditional cakes in South Sulawesi which is very popular within the community. Pisang ijo is made from Moringa oleifera leaf flour and extract, wheat flour, plantain, sugar, and salt which is processed using steaming methods. Pisang ijo was served with vanilla sauce. The purpose of the study was to describe the process of making moringa leaf flour and extract, knowing how to process it and find out the results of organoleptic tests of green banana cake by using the substitution of moringa leaf extract (F1) and moringa leaf flour (F2). The research method used was an organoleptic test method using 30 investigators divided into three groups: 10 expert examiners, 10 trained investigators, and 10 untrained investigators. Laboratory tests using spectrophotometric were carried out to determine the nutritional content of moringa leaf flour and extract. The organoleptic test results show that from the aspect of color, the most preferred product by the panelists is the F1 product which produces a lighter green color. The F2 product is less bright. The hedonic test results of aroma, texture, and sense show that the product most preferred by the panelists is the F2 product. Proximate test results indicate a better nutritional content in F2 products, i.e., the protein and vitamin C content are higher, which are 3.38% and 153.2 μg g−1, respectively than the F1 product.
ICT Strategy and Micro-Entrepreneurs Growth: The Indonesian Case
Authors: Anwar Misita , Djawad Yasser A. , Ridwansyah
Published: June 2019

The importance of Information and Communication Technology has been recognized but often undervalued by small businesses. Furthermore, best practices of ICT use in large companies do not always translate to a small business environment. Few studies have been done at the intersection of ICT and Micro and Small Enterprises (MSEs) in a ‘holistic’ manner taking into consideration various aspects of ICT adoption and use. The LIAISE framework provides guidelines for investigating various aspects of ICT adoption and use, including ICT literacy, information, and content, access, infrastructure and support, and evaluation. The framework was originally developed for the non-profit sector and has been applied in the small business context by examining MSEs in developing countries. Using a case study in Indonesia, this paper will use LIAISE as an analytical framework to investigate mobile phone adoption and use by micro-entrepreneurs.