bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-hump bright and dark solitons for the Schrödinger-Korteweg-de Vries coupled system
Authors: Parra Prado Hugo , Cisneros-Ake Luis A.
Published: May 2019

The Hirota bilinear method is extended to find one- and two-hump exact bright and dark soliton solutions to a coupled system between the linear Schrödinger and Korteweg–de Vries (KdV) equations arising in the energy transfer problem along a cubic anharmonic crystal medium. The bilinear form associated to this system is found by imitating the well known bilinearizing transformations used in the standard nonlinear Schrödinger (NLS) and KdV equations. Proper finite exponential expansions in the transformed variables allow one to exhibit multihump soliton solutions as single entities resulting from the adjustment of appropriate dispersion relations between the wave parameters describing the profiles. It is found that such one- and two-hump solutions correspond to the one- and two-KdV solitons trapped by both the bright and dark-gray NLS solitons. Our two-hump bright and dark solutions represent novel solutions for the type of interactions and nonlinearities considered.
A needle-rectangular loop sterilizer with self-ejected plasma by using positive and negative direct-current voltages
Authors: Li Hua , Du Xiaoxia , Jiang Linxiu , Deng Shejiao , Xie Shouru , Zeng Peng , Zeng Ruosheng , Jiang Yongrong , Chen Zhencheng
Published: May 2019

We designed a portable direct-current (DC) jet sterilizer that discharges self-excited plasma through a needle-rectangular loop sterilizer. The device is sized ∅ 30 mm × 40 mm. The tungsten needle is connected to the high voltage source and to the copper rectangular loop with earthing wire. Under high-voltage DC (±9.6 kV) at atmospheric pressure, the plasma jets killed Escherichia coli and Staphylococcus aureus in the absence of an externally connected carrier gas. Under the same conditions, the E. coli and S. aureus were destroyed after 90 s and 120 s respectively by the positive plasma jet, and after 120 s and 150 s respectively by the negative plasma jet. Thus, the sterilization efficiency of the positive plasma jet exceeds that of the negative plasma jet.
Ultra-narrow electromagnetically induced transparency in the visible and near-infrared regions
Authors: Wang Qiao , Ma Liyun , Cui Wenli , Chen Maodu , Zou Shengli
Published: May 2019

The electromagnetically induced transparency (EIT) phenomenon is of great importance for plenty of applications, such as slow light, nonlinear effect, nanosensing, and metamaterials. The linewidth is a key factor to evaluate the characteristic of EIT, because the drastic change in dispersion in the narrow spectra can make good control of light. However, only a few reports are related to the ultranarrow EIT. In this paper, we propose a nanosystem based on a gold grating and a multilayer structure. An ultranarrow spectral EIT peak with a linewidth range of 0.75–1.5 nm is observed in such a nanosystem in the visible and near-infrared regions. The physical mechanism leading to the phenomenon is different from those in previous works. In the proposed nanosystem, the ultranarrow EIT peak is formed by the destructive interference of the Fabry-Perot resonance and waveguide modes. Analytic results calculated from the model equations are also found to be consistent with numerical simulations for both normal and oblique incidences. Our work provides another efficient way to realize an ultranarrow EIT.
Polycrystalline thin-film transistors fabricated on high-mobility solid-phase-crystallized Ge on glass
Authors: Moto K. , Yamamoto K. , Imajo T. , Suemasu T. , Nakashima H. , Toko K.
Published: May 2019

Low-temperature formation of Ge thin-film transistors (TFTs) on insulators has been widely investigated to improve the performance of Si large-scale integrated circuits and mobile terminals. Here, we studied the relationship between the electrical properties of polycrystalline Ge and its TFT performance using high-mobility Ge formed on glass using our recently developed solid-phase crystallization technique. The field-effect mobility μFE and on/off currents of the accumulation-mode TFTs directly reflected the Hall hole mobility μHall, hole concentration, and film thickness of Ge. By thinning the 100-nm thick Ge layer with a large grain size (3.7 μm), we achieved a high μHall (190 cm2/Vs) in a 55-nm thick film that was almost thin enough to fully deplete the channel. The TFT using this Ge layer exhibited both high μFE (170 cm2/Vs) and on/off current ratios (∼102). This is the highest μFE among low-temperature (<500 °C) polycrystalline Ge TFTs without minimizing the channel region (<1 μm).
Powerful continuous-wave sub-terahertz electron maser operating at the 3rd cyclotron harmonic
Authors: Kalynov Yu. K. , Manuilov V. N. , Fiks A. Sh. , Zavolskiy N. A.
Published: May 2019

Coherent subterahertz radiation is achieved in an electron cyclotron maser (large-orbit gyrotron configuration) operating at a higher cyclotron harmonic in the continuous-wave generation regime. This auto-oscillator is based on the use of a gun with a magnetic field cusp and a section for adiabatic magnetic compression with a factor of 1000, forming a 30 keV/0.7 A axis-encircling electron beam in a magnetic field of 5 T. A stable single-mode generation is achieved in the case of operation at the third and second cyclotron harmonics at frequencies of 0.394 THz and 0.267 THz with radiation powers of 0.37 kW and 0.9 kW, respectively.
Energy levels and charge state control of the carbon antisite-vacancy defect in 4H-SiC
Authors: Son Nguyen Tien , Stenberg Pontus , Jokubavicius Valdas , Abe Hiroshi , Ohshima Takeshi , Ul Hassan Jawad , Ivanov Ivan G.
Published: May 2019

The carbon antisite-vacancy pair (CSiVC) in silicon carbide (SiC) has recently emerged as a promising defect for applications in quantum communication. In the positive charge state, CSiVC+ can be engineered to produce ultrabright single photon sources in the red spectral region, while in the neutral charge state, it has been predicted to emit light at telecom wavelengths and to have spin properties suitable for a quantum bit. In this electron paramagnetic resonance study using ultrapure compensated isotope-enriched 4H-28SiC, we determine the (+|0) level of CSiVC and show that the positive and neutral charge states of the defect can be optically controlled.
Measurement of non-isothermal transport coefficients in a near-eutectic succinonitrile/(d)camphor mixture
Authors: Schraml M. , Sommer F. , Pur B. , Köhler W. , Zimmermann G. , Witusiewicz V. T. , Sturz L.
Published: May 2019

We have determined nonisothermal diffusive transport coefficients of a succinonitrile-(d)camphor mixture with a composition of c = 0.239 wt.-frac. (d)camphor at a temperature of 318.2 K, which is close to the eutectic point. The employed experimental techniques are optical beam deflection in a Soret cell and photon correlation spectroscopy. The diffusion coefficient is D = (1.43 ± 0.04) × 10−10 m2 s−1, the thermodiffusion coefficient is DT = (2.00 ± 0.06) × 10−12 m2 s−1 K−1, and the Soret coefficient is ST = (1.40 ± 0.02) × 10−2 K−1. Camphor migrates toward the lower and succinonitrile migrates toward the higher temperatures. While the diffusion coefficient is in good agreement with the literature, the Soret coefficient has been determined for the first time. Our analysis shows that a significant concentration shift can be established in the liquid mixture in the presence of a temperature gradient. The mixture has a negative separation ratio, which leads to convective instabilities if heated from above.
Magnetically and optically tunable terahertz radiation from Ta/NiFe/Pt spintronic nanolayers generated by femtosecond laser pulses
Authors: Adam Roman , Chen Genyu , Bürgler Daniel E. , Shou Tianyu , Komissarov Ivan , Heidtfeld Sarah , Hardtdegen Hilde , Mikulics Martin , Schneider Claus M. , Sobolewski Roman
Published: May 2019

We generate terahertz (THz) transients by illuminating a few-nanometer-thick Ta/NiFe/Pt nanolayers with a train of linearly polarized 100-fs-wide laser pulses. The transients are ∼1-ps-wide free-space propagating bursts of electromagnetic radiations with amplitudes that are magnetically and optically tunable. Their spectral frequency content extends up to 5 THz, and the 3-dB cutoff is at 0.85 THz. The observed transient electromagnetic signals originate from the NiFe/Pt bilayer, and their amplitude dependence on the external magnetic field, applied in the sample plane, very closely follows the static magnetization versus magnetic field dependence of the NiFe film. For the same laser power, excitation with highly energetic, blue light generates THz transients with amplitudes approximately three times larger than the ones resulting from excitation by infrared light. In both cases, the transients exhibit the same spectral characteristics and are linearly polarized in the perpendicular direction to the sample magnetization. The polarization direction can be tuned by rotation of the magnetic field around the laser light propagation axis. The characteristics of our THz spintronic emitter signals confirm that THz transient generation is due to the inverse spin Hall effect in the Pt layer and demonstrate that ferromagnet/metal nanolayers excited by femtosecond laser pulses can serve as efficient sources of magnetically and optically tunable, polarized transient THz radiation.
Magic numbers, quantum delocalization, and orientational disordering in anionic hydrogen and deuterium clusters
Authors: Kohno Bridgett H. , Mallory Joel D. , Mandelshtam Vladimir A.
Published: May 2019

The Diffusion Monte Carlo (DMC) method was applied to anionic hydrogen clusters H−(H2)n (n = 1–16, 32) and their deuterated analogs using a polarizable all-atom potential energy surface (PES) developed by Calvo and Yurtsever. For the hydrogen clusters, the binding energy ΔEn appears to be a smooth function of the cluster size n, thus contradicting the previous claim that n = 12 is a “magic number” cluster. The structures of the low energy minima of the PES for these clusters belong to the icosahedral motif with the H2 molecules aligned toward the central H− ion. However, their ground state wavefunctions are highly delocalized and resemble neither the structures of the global nor local minima. Moreover, the strong nuclear quantum effects result in a nearly complete orientational disordering of the H2 molecules. For the deuterium clusters, the ground state wavefunctions are localized and the D2 molecules are aligned toward the central D− ion. However, their structures are still characterized as disordered and, as such, do not display size sensitivity. In addition, DMC simulations were performed on the mixed H−(H2)n(D2)p clusters with (n, p) = (6, 6) and (16, 16). Again, in contradiction to the previous claim, we found that the “more quantum” H2 molecules prefer to reside farther from the central H− ion than the D2 molecules.
Extending the Einstein crystal method to molecular constraints with an outlook on drug discovery
Authors: Frank Jodi Ackerman
Published: May 2019

New paper extends the Einstein crystal method to calculate solubilities of molecular systems subject to constraints, a common scenario in practical molecular simulations.
What can echolocation recordings reveal about the foraging ecology of Saccolaimus saccolaimus (Emballonuridae) in north-western Australia?
Authors: McKenzie N. L. , Bullen R. D.
Published: May 2019

Echolocation sequences reveal aspects of the foraging ecology of Saccolaimus saccolaimus (Emballonuridae). In combination, pulse peak-frequency and fineness-of-tuning values derived from free-flying search-mode echolocation sequences emitted by S. saccolaimus in north-western Australia imply that it generally forages in uncluttered airspaces using an air superiority foraging strategy. Wing-beat frequency values, derived from pulse repetition rates in these sequences, reveal that it has a maximum aerobic level-flight speed of 8.1 m s–1 (used for foraging). These predictions are consistent with deductions based on airframe design parameters taken from museum specimens, and with available field observations. The echolocation recordings provided a quick, passive, cost-effective characterisation of foraging niche, useful for conservation planning.
A global model of island species–area relationships
Authors: Matthews Thomas J. , Rigal François , Triantis Kostas A. , Whittaker Robert J.
Published: May 2019

Significance

The island species–area relationship (ISAR) is a fundamental diversity pattern, best described by the power model. Biogeographic theory assumes predictable variation in power model parameters in relation principally to system isolation, but these assumptions are only weakly supported by previous work, which has been limited in considering the two parameters separately and oversimplistically. By developing and testing a hierarchical (structural equation) model of factors influencing ISAR form, we show that island species diversity patterns are shaped by intra-archipelago processes more strongly than by isolation from mainland source pools. These findings point to a need to quantify the role of differing scales of isolation in influencing propagule exchange among insular systems to develop improved predictive diversity models.
Preformed chromatin topology assists transcriptional robustness ofShhduring limb development
Authors: Paliou Christina , Guckelberger Philine , Schöpflin Robert , Heinrich Verena , Esposito Andrea , Chiariello Andrea M. , Bianco Simona , Annunziatella Carlo , Helmuth Johannes , Haas Stefan , Jerković Ivana , Brieske Norbert , Wittler Lars , Timmermann Bernd , Nicodemi Mario , Vingron Martin , Mundlos Stefan , Andrey Guillaume
Published: May 2019

Long-range gene regulation involves physical proximity between enhancers and promoters to generate precise patterns of gene expression in space and time. However, in some cases, proximity coincides with gene activation, whereas, in others, preformed topologies already exist before activation. In this study, we investigate the preformed configuration underlying the regulation of theShhgene by its unique limb enhancer, theZRS, in vivo during mouse development. Abrogating the constitutive transcription covering theZRSregion led to a shift within theShh–ZRScontacts and a moderate reduction inShhtranscription. Deletion of the CTCF binding sites around theZRSresulted in the loss of theShh–ZRSpreformed interaction and a 50% decrease inShhexpression but no phenotype, suggesting an additional, CTCF-independent mechanism of promoter–enhancer communication. This residual activity, however, was diminished by combining the loss of CTCF binding with a hypomorphicZRSallele, resulting in severeShhloss of function and digit agenesis. Our results indicate that the preformed chromatin structure of theShhlocus is sustained by multiple components and acts to reinforce enhancer–promoter communication for robust transcription.
Nut analysis.
Authors: Widodo P. , Nur F. , Nafisah E. , Forster B. P. , Hasibuan H. A.
Published: May 2019

Nut analysis provides data on: percentage of shell in the fruit (S/F); shell to kernel (S/K); percentage of kernel in the fruit (K/F); kernel weight (KW); nut weight (NW); kernel to nut (K/N); and percentage of kernel in the bunch (K/B). Nuts should be oven dried at 60-105°C for seven to nine hours, followed by cracking the nut shell to release the kernel.
Conservation agriculture systems.
Authors: Mitchell J. P. , Reicosky D. C. , Kueneman E. A. , Fisher J. , Beck D.
Published: May 2019

Despite positive trajectories in global production during the last century, projected food demand and limits on our ability to further expand cropland now dictate an increase in food production by roughly 70% during the first half of the twenty-first century. Conventional systems of agriculture with their general emphasis on intensive soil disturbance, limited biodiversity, monoculture cropping and practices that mine the resource base are extractive and have resulted in slow yet demonstrably severe environmental degradation that ultimately jeopardizes food security for future generations. Because future gains in production are unlikely to be achieved by further increases in genetic yield potential, as have been achieved in the past, applications of new production system paradigms are going to be indispensable. Our existing ones are no longer able to compensate for, nor reverse, the environmental problems they have caused. We summarize the history of how agricultural systems have come to be what they are today and identify ways in which these systems will need to be improved to meet future food security challenges. We describe the development of food production system options that have been proposed in recent decades and show that the core principles and concepts of what are widely regarded as conservation agriculture (CA) systems provide an important unifying framework. Our chapter provides evidence for why these systems, when flexibly applied and in ways that mimic natural ecosystems, provide a best-bet approach for moving forward. We highlight a series of examples of CA systems being applied around the world and conclude by issuing a call to action aimed at developing and more widely adopting food production systems that look long-term, mimic natural systems and transcend jargon.
Construction of Complete Orthogonal Genuine Multipartite Entanglement State*
Authors: Wu Feng-Lin , Liu Si-Yuan , Yang Wen-Li , Fan Heng
Published: May 2019

With the development of quantum information processing, multipartite entanglement measures are needed in many cases. However, there are still no complete orthogonal genuine multipartite entanglement (GME) bases available as Bell states to bipartite systems. To achieve this goal, we find a method to construct complete orthogonal GME states, and we exclude many equivalent states by leveraging the group theory. We also provide the case of a 3-order 3-dimensional Hilbert space as an example and study the application of general results in the dense coding scheme as an application. Moreover, we discuss some open questions and believe that this work will enlighten extensive studies in this field.
Negative Parity States in 39Cl Configured by Crossing Major Shell Orbits*
Authors: Tao Long-Chun , Ichikawa Y. , Yuan Cen-Xi , Ishibashi Y. , Takamine A. , Gladkov A. , Fujita T. , Asahi K. , Egami T. , Funayama C. , Imamura K. , Lou Jian-Ling , Kawaguchi T. , Nishizaka T. , Sato T. , Tominaga D. , Yang Xiao-Fei , Yamazaki H. , Ye Yan-Lin , Ueno H.
Published: May 2019

Traditional “magic numbers” were once regarded as immutable throughout the nuclear chart. However, unexpected changes were found for unstable nuclei around N = 20. With both proton and neutron numbers around the magic number of 20, the neutron-rich 39Cl isotope provides a good test case for the study of the quantum-state evolution across the major shell. In the present work, the negative parity states in 39Cl are investigated through the β decay spectroscopy of 39S. Newly observed γ transitions together with a new state are assigned into the level scheme of 39Cl. The spin parity of 5/2− for the lowest negative parity state in 39Cl is reconfirmed using the combined γ transition information. These systematic observations of the negative parity states in 39Cl allow a comprehensive comparison with the theoretical descriptions. The lowest 5/2− state in 39Cl remains exotic in terms of comparisons with existing theoretical calculations and with the neighboring isotopes having similar single-particle configurations. Further experimental and theoretical investigations are suggested.
Carrier Envelope Phase Description for an Isolated Attosecond Pulse by Momentum Vortices*
Authors: Li Meng , Zhang Gui-zhong , Ding Xin , Yao Jian-quan
Published: May 2019

As a crucial parameter for a few-cycle laser pulse, the carrier envelope phase (CEP) substantially determines the laser waveform. We propose a method to directly describe the CEP of an isolated attosecond pulse (IAP) by the vortex-shaped momentum pattern, which is generated from the tunneling ionization of a hydrogen atom by a pair of time-delayed, oppositely and circularly polarized IAP-IR pulses. Superior to the angular streaking method that characterizes the CEP in terms of only one streak, our method describes the CEP of an IAP by the features of multiple streaks in the vortex pattern. The proposed method may open the possibility of capturing sub-cycle extreme ultraviolet dynamics.
First-Principles Investigation on the Fully Compensated Ferrimagnetic Behavior in Ti2NbSb and TiZrNbSb*
Authors: Feng Lin , Zhang Xue-Ying
Published: May 2019

The electronic structures of Ti2NbSb with Hg2CuTi structure and TiZrNbSb with LiMgPdSn structure are investigated using first-principles calculations. The results indicate that Ti2NbSb is a fully compensated ferrimagnetic spin-gapless semiconductor with an energy gap of 0.13 eV, and TiZrNbSb is a half-metallic fully compensated ferrimagnet with a half-metallic gap of 0.17 eV. For Ti2NbSb, the total energy of the Hg2CuTi structure is 0.62 eV/f.u. higher than that of the L21 structure, which is the ground state, and for TiZrNbSb, the total energy of the structure considered in this work is only 0.15 eV/f.u. larger than that of the ground state. Thus both of them may be good candidates for spintronic applications.
Improvement of Performance of HfS2 Transistors Using a Self-Assembled Monolayer as Gate Dielectric*
Authors: Zhang Wen-Lun
Published: May 2019

This work details a study based on HfS2 transistors utilizing an n-octadecylphosphonic acid-based self-assembled monolayer (SAM) as the gate dielectric. The fabrication of the SAM-based two-dimensional (2D) material transistor is simple and can be used to improve the quality of the interface of air-sensitive 2D materials. In comparison to HfS2 transistors utilizing a conventional Al2O3 gate insulator by atomic layer deposition, HfS2 transistors utilizing an SAM as the gate dielectric can reduce the operation region from 4V to 2V, enhance the field-effect mobility from 0.03 cm2/Vs to 0.75 cm2/Vs, improve the sub-threshold swing from 404 mV/dec to 156 mV/dec, and optimize the hysteresis to 0.03 V, thus demonstrating improved quality of the semiconductor/insulator interface.
Classical Ground State Spin Ordering of the Antiferromagnetic J1–J2 Model*
Authors: Zhu Ren-Gui
Published: May 2019

The classical frustrated antiferromagnetic J1–J2 model is considered in a description of the classical spin wave for a vector spin system. Its ground state (GS) spin ordering is analyzed by minimizing its energy. Our analytical derivations show that all the spins in the GS phase must lie in planes that are parallel to each other. When applying the derived formulations to concrete lattices such as the square and simple cubic lattices, we find that in the large J2 region, a large continuous GS degeneracy concluded by a qualitative analysis is lifted, and collinear striped ordering is selected as the GS phase.
Nonlinear Optical Rectification, Second and Third Harmonic Generations in Square-Step and Graded-Step Quantum Wells under Intense Laser Field
Authors: Ozturk O. , Ozturk E. , Elagoz S.
Published: May 2019

For square-step quantum wells (SSQWs) and graded-step quantum wells (GSQWs), the nonlinear optical rectification (NOR), second harmonic generation (SHG) and third harmonic generation (THG) coefficients under an intense laser field (ILF) are analyzed. The found results indicate that ILF can ensure a vital influence on the shape and height of the confined potential profile of both SSQWs and GSQWs, and alterations of the dipole moment matrix elements and the energy levels are adhered on the profile of the confined potential. According to the results, the potential profile and height of the GSQWs are affected more significantly by ILF intensity compared to SSQWs. These results indicate that NOR, SHG and THG coefficients of SSQWs and GSQWs may be calibrated in a preferred energy range and the magnitude of the resonance peak (RP) by tuning the ILF parameter. It is feasible to classify blue or red shifts in RP locations of NOR, SHG and THG coefficients by varying the ILF parameter. Our results can be useful in investigating new ways of manipulating the opto-electronic properties of semiconductor QW devices.
Adaptive reconstruction for electrical impedance tomography with a piecewise constant conductivity
Authors: Jin Bangti , Xu Yifeng
Published: May 2019

In this work we propose and analyze a numerical method for electrical impedance tomography to recover a piecewise constant conductivity from boundary voltage measurements. It is based on standard Tikhonov regularization with a Modica–Mortola penalty functional and adaptive mesh refinement using suitable a posteriori error estimators of residual type that involve the state, adjoint and variational inequality in the necessary optimality condition and a separate marking strategy. We prove the convergence of the adaptive algorithm in the following sense: the sequence of discrete solutions contains a subsequence convergent to a solution of the continuous necessary optimality system. Several numerical examples are presented to illustrate the convergence behavior of the algorithm.
Multicriteria land index for determining primary commodity in agricultural landuse planning
Authors: Widiatmaka  , Mulya Setyardi Pratika , Panuju Dyah Retno , Ambarwulan Wiwin , Hamzah Umar
Published: May 2019

Regional development usually start with identifying regional potencys. Defining a local potencies such as primary agricultural commodities is a basic capital in developing regional economic. The concept of determination is pointed by Barlowe (1986), which include bio-physically suitable, economically feasible and institutionally acceptable. The approach (analysis) used in this research is Geographic Information System (GIS), commodity base analysis (LQ), differential shift (SSA), gross margin (GM), distance to market location, process hierarchy analysis (AHP), and multicriteria land index. This research is located in transmigration area of Rawa Pitu Sub District, Tulang Bawang Regency, Indonesia. This research aims to identify basic commodities for each village. The results shows that several land parameters which include land suitability and accessibility, comodity parameters which include LQ and SSA as well as economic parameters which include GM can be used to determine primary commodity in a region. They composed what we call as multicriteria land index. There were some basic commodities identified using such index, which include paddy, maize, rubber, and oil-palm. Paddy is a primary comodities in certain villages. Whereas maize and oil palm is a primary comodities in another villages. Rubber is not a primary comodities in any village.
Drought monitoring using LISAT (LAPAN-IPB Satellite) and Landsat 8 Satellite Imagery in Pakisjaya District, West Java
Authors: Amalo Luisa Febrina , Nur Irza Arnita , Rochimawati Nur Riana
Published: May 2019

Drought is a natural hazard indicated by the decreasing of rainfall and water storage in the region and impacting agricultural sector. Recently, satellites data are widely used for calculating the drought indices. Since 2010, Bogor Agricultural University (IPB) and the National Institute of Aeronautics and Space of Indonesia (LAPAN) had launched satellite, called “LISAT” LAPAN-IPB Satellite. The objectives of the research are (1) to compare NDVI values from two different satellites –LISAT and Landsat (2) to analyzed the relationship between climate variability using spatial rainfall data with NDVI values over Pakisjaya District in specific time of study, (3) to validate NDVI derived from LISAT data with field observation. The study area will focus in Pakisjaya District, Karawang, West Java, one of Java agricultural production center. The biggest potentials in Pakisjaya district are agriculture, plantations and fish ponds. Therefore, the identification of drought in Cirebon is expected to be used as an early warning of drought and mitigation measures to reduce the impact of drought on agricultural sustainability. The results showed drought occurrence in 2017 was caused by the shifting of wet season. Wet season that should occurred in January, but from rainfall estimation using CMORPHs, wet season was delayed to April. It is associated with NDVI data derived from LISAT and Landsat 8 results. Highest NDVI was found in April, and the lowest NDVI was found in January. Nevertheless, NDVI value derived from LISAT were low than literature, but generally from the pattern, it can differentiate well different land used observed. Overall, this study can be used as drought mitigation, particularly for the agricultural farmers, so that they can arrange the suitable planting time.
Influence of the Indian Ocean Dipole (IOD) on Convectively Coupled Kelvin and Mixed Rossby-Gravity Waves
Authors: Muhammad Fadhlil R , Lubis Sandro W. , Tiarni Inka , Setiawan Sonni
Published: May 2019

Indian Ocean Dipole (IOD) is a mode of natural climate variability that arises from a zonal-dipole structure in interannual variations of the tropical Indian Ocean. Understanding the influence of IOD on atmospheric circulation is important in order to improve weather forecasts and climate predictions in the Tropics and the extratropics on time scales beyond a few days. This study investigates the role of IOD on convectively coupled equatorial wave (CCEW) activity, including Kelvin and MRG waves and examines the potential links between them. The results show that positive IOD event leads to enhance Kelvin wave and MRG wave activities over the eastern Africa and southern Indian Ocean. On the other hand, it suppresses Kelvin and MRG wave activities over the eastern Indian Ocean and the Maritime continent. It is also shown that IOD’s influence on Kelvin and MRG waves activity is non-dependent to ENSO activity. These results highlight the importance of IOD in generating Kelvin and MRG waves in the tropics.
Unprecedented Quasi-Biennial Oscillation (QBO) disruption in 2015-2016: Implications for tropical waves and ozone
Authors: Kusuma Lintang , Lubis Sandro W. , Setiawan Sonni
Published: May 2019

During the Northern Hemisphere (NH) winter of 2015/16, quasi-biennial oscillation (QBO) exhibited a significant disruption that was unprecedented in the observational record. It was characterized by an upward displacement of the westerly wind anomalies. Since traveling wave activity induces the QBO and in turn affects the ozone distribution, it is worth understanding how this anomalous change affects tropical waves activity (including Kelvin and MRG waves) and ozone. This study used assimilated ozone product from the Modern-Era Retrospective Analysis version 2 (MERRA2). The results showed that Kelvin and MRG wave activities are appreciably strong during this period. The strengthening of Kelvin wave activity is consistent with a persistent westerly background flow, favoring upward propagation of Kelvin waves into the stratosphere. On the other hand, the significant strengthening of MRG wave activity may be associated with enhanced equatorward propagation of extratropical Rossby waves due to strong El-Nino event. Furthermore, the results also indicated that the anomalous change in the QBO leads to increasing temperature and ozone concentration in the tropical lower stratosphere. Based on ozone budget analysis, we showed that the increase in total ozone tendency is largely attributable to the increase in dynamical ozone transport, being consistent with the QBO-induced residual circulation between the mid and low latitude, in the lower stratosphere.
Carbon Dioxide Sequestration Capability of Green Spaces in Bogor City
Authors: Hazarin Azra Q. , Rokhmatuloh  , Ash Shidiq Iqbal Putut
Published: May 2019

Biomass estimation can be used to estimate the stock of carbon dioxide. Bogor City is one of the hinterland of Jakarta, which has a significant increase in population growth rate, especially in 1990-2000 when the number hit 10,25% and the average 3,373 vehicles each month of increase of the which provides a significant emission of carbon dioxide. This research uses three different Vegetation Indices such as NDVI, MSAVI2 and ARVI to estimate the best index to build a biomass models with 73 in-situ measurements and convert it to carbon stock estimation. This research aim at 1) looking for vegetation index which is best to be used for urban green spaces (identification ?) and 2) estimation of carbon stock of urban green spaces in the city of Bogor. 3) carbon dioxide absorption estimation of Bogor city. The result shows MSAVI2 as the best index of 61.8% correlation with rather that NDVI (42.35%) and ARVI (43.7%). Every districts in Bogor can not absorb its carbon dioxide emission with the total of 5,931,131 tons of carbon dioxide unabsorb.
Plant species diversity and cluster analysis in difference logged-over peat swamp forests in Riau, Indonesia
Authors: Basyuni M , Jayusman
Published: May 2019

Peat swamp forest is one of the wetland tropical rainforest ecosystems widespread in Indonesia. This study aimed to analyze plant species diversity of tree stage in difference logged-over peat swamp forests at PT. Diamond Raya Timber, Riau Province. This study site was divided into three different locations, newly logged-over peat forest swamp forest (NLPSF), three years logged-over peat swamp forest (3LPSF) and four years logged-over peat swamp forest (4LPSF). Primary species of tree stage in the study site were grouped into three parts, i.e., firstly, Dipterocarpaceae family mainly consists of meranti bunga (Shorea teysmanniana) and meranti batu (S. uliginosa), secondly, non-Dipterocarpaceae included balam (Palaquium hexandrum), milas (Parastemon urophyllus), macang (Mangifera havilandii), punak (Tetramerista glabra), jambu (Eugenia sp), pisang-pisang (Mezzetia parviflora), and arang-arang (Gynotroches axillaries), and thirdly, particular species of ramin (Gonystylus bancanus). The pattern of species grouping for tree level was more centered in the NLPSF compared to other sites. On the other hand, species diversity in tree level found more diverse in 4LPSF, suggested the various ecological parameters. Cluster analysis showed the occurrence of species relationship in the sites based on diameter and importance values indicated the presence of species similarity and habitat preference.
The dynamic changes of Barito basin peat land ecosystem in South Borneo, Indonesia
Authors: Yunandar  , Effendi Hefni , Widiatmaka  , Setiawan Yudi
Published: May 2019

The dynamic changes of aquatic ecosystem have an important role in order to maintain the sustainability of peat land ecosystem. The aquatic ecosystem is the main supply of freshwater in the Barito basin region, contribute to the water quality for consumption and production, habitat for aquaculture. Therefore, the spatial modelling of inundation changes is a pre-requisite for future peat land management. This study employed GIS and Remote Sensing techniques to monitored land cover/land use changes for observed inundation in Barito basin, South Borneo, Indonesia using multispectral satellite data obtained from Landsat at 1994, 1996, 2013 and 2015 respectively. The Barito peat basin areas, based on object dominance, were classified into five cover classes/dry land use compilation namely swamp bushes, open areas, transportation, galam vegetation (Melaleuca sp) and water bodies. The truth value was 88.48% for Overall Accuracy and 0.8 for Kappa which belonged to the substantial category. Land cover/land use resulting from spatial analysis showed a significant increase in water bodies totally 24% from 14% in 1994. Inundations that were close to the Barito river flow had a typical permanent compared to those that were far from the river. Regarding inundations throughout the season contributed to the management and development of the socio-economic area.
Location Characteristic of Seaweed Cultivation Based On Image Processing and People Perception in Amal Coast, Tarakan Island
Authors: Aulia Arti , Susiloningtyas Dewi , Handayani Tuty
Published: May 2019

Amal coast in Tarakan Island famous for seaweed production. This research aims to know the location characteristic of seaweed cultivation from people perception, and to know the connection of the people perception with certain factors such as: the family income, the length of stay, and the impact of seaweed cultivation on society and environment. Research location was based on the purposive sampling in Amal Coast which was the main location of seaweed cultivation. Furthermore, searching for additional data from informant who’s recommended by key informant. This method based on snowball sampling. Location characteristic of seaweed cultivation seen based on Landsat 8 image processing. The data were compiled and validated by survey using question-answer method which was based on the research variables. Data analysis in this research was qualitative descriptive method, to provide a description and explanation of research variables. Interactive data model analysis from Miles and Huberman, which started with data collection process, data simplification, data presentation, and conclusion of research. Results from this study showed that people’s perception determine characteristics of location for seaweed cultivation in Amal Coast, East Tarakan. Location that provide more income and more long-term business will be increasingly in demand.
Community Structure of Macrozoobenthos at Blanakan Fish Pond, Subang, West Java
Authors: Choirunnisa  , Takarina N D
Published: May 2019

Macrozoobenthos has an important role as detritivore in water ecosystem. Macrozoobenthos community also act as a biomonitoring instrument. The purpose of this study is to know the composition, density, diversity, evenness, and dominance of macrozoobenthos at Blanakan Fish Pond. This study was done from February to June 2018. Macrozoobenthos samples were collected from 3 stations and each station consist of 3 fish ponds. Sampling on each ponds was done by purposive random sampling on 3 sampling points with twice repetition on each point. Water abiotic factors sampling was done on each points. Macrozoobenthos samples were identified and analyzed using Shannon-Wiener diversity index, Pielou evenness index, Simpson’s dominance index, Sorensen similarity index, and t-test. The results showed that there are six species of macrozoobenthos from 3 classes found, which are Melanoides tuberculata, Brotia costula, Cerithidea cingulata, Nephtys inornata, Cossura sp., and Erpobdella sp. Highest species density at Blanakan Fish Ponds is Brotia costula, amounting to 10907 ind./m3. The diversity and evenness of macrozoobenthos at Blanakan Fish Ponds classified as low and there is a dominant species at Blanakan Fish Ponds. There is no difference between macrozoobenthos diversity on 3 stations.
The potency of Sentinel-2 satellite for monitoring during and after coral bleaching events of 2016 in the some islands of Marine Recreation Park (TWP) of Pieh, West Sumatra
Authors: Wouthuyzen Sam , Abrar M , Corvianawatie C , Salatalohi A , Kusumo S , Yanuar Y , Darmawan  , Samsuardi  , Yennafri  , Arrafat M Y
Published: May 2019

The coral bleaching event (CBE) which trigerred by increase in sea temperatures of 1-2˚C during El-Nino can make corals stressful or potentially dead. Many CBE research are conducted using sea temperature data measured through infrared thermal (TIR) satellite sensor. However, very few study use optical remote sensing data. This study aim to analyze the potential of optical Sentinel-2 (S-2) satellite data for monitoring during (Jun. 2016) and after (Jun. 2018) CBE in small islands of marine protected areas (TWP) of Pieh. A series image analysis procedure was conducted, i.e. simple DOS atmospheric correction; normalizating digital numbers (DN) of Blue, Green and Red bands of subject images during and after CBE to the reference image (before CBE. Dec. 2015) using “pseudo invariant feature (PIF)” approach; subtracting the DN of each bands of images during and after CBE to the reference image, and generating color composite of natural color with a contrast stretch. Result showed that this procedure can detected clearly the CBE. There was an average decreasing bleaching trend of 1.63 ha (15.8%), which indicated that some corals have recovered from thermal stress inside the TWP of Pieh. However, islands outside the TWP of Pieh, showed an increasing trend by an average of 0.50 ha (21.2%). The predation corals by the crown of thorn seastar, Acanthaster planci, whose population exploded after CBE was the main reason why CBE still detected both inside and outside the TWP of Pieh. This study shows the ability and potency of optical remote sensing data of S-2 satellite to monitor CBE, but need a lot of validation from many other sites. This result is very useful for supporting project such as COREMAP CTI.
Development of bathymetry extraction model from SPOT 7 satellite image
Authors: Setiawan K T , Ginting D N BR , Winarso G , Manessa M D M , Anggraini N , Julzarika A , Effendi I , Surahman  , Rosid S , Supardjo A H
Published: May 2019

Bathymetry extraction using remote sensing technology still continues up to now. The technology improvement should be parallel with the accuracy product. The high accuracy of bathymetry extraction become a hope for all users. Improvement accuracy of bathymetry information from remote sensing data extraction is done by various processing method. In this study, in-situ sampling data technique is used to object aquatic marine habitat. The purpose of this study was to determine the bathymetric information model of SPOT 7 satellite image extraction and determine the accuracy produced. The model used is band ratio by Stumpf. The SPOT 7 satellite image data acquisition on June 28th 2018 Is used in the shallow waters of Gili Trawangan, Gili Meno, and Gili Air, Lombok Island, West Nusa Tenggara Province. The determination of bathymetry extraction results from the method is 62.64% and the mean error value of 4.32m.
Turbulent mixing of water masses in Selayar Slope - Southern Makassar Strait
Authors: Prihatiningsih I , Jaya I , Atmadipoera A S , Zuraida R
Published: May 2019

During the Java-Makassar-Flores (JMF) Cruise in August 2015 onboard the RV GEOMARIN 3, about 56 hydrographic CTD profiles have been acquired in the JMF confluence region of Makassar Indonesian Throughflow (ITF) and seasonal Java-Flores Current, where three intensive 24-h CTD “yoyo” measurement were carried out in Dewakang sill, Selayar slope and Kangean slope. The aim of this paper is to estimates the turbulent mixing value using Thorpe analysis, particularly in the Selayar slope - southern Makassar Strait. It is found that below surface potential density of 24.25 σθ stratification of water masses is dominated by Makassar ITF with salty (34.6 psu) North Pacific thermocline water (NPSW) and less salty (34.42 psu) North Pacific lower-thermocline water (NPIW). However, above 24.25 σθ upper NPSW is drastically dominated by much fresher water (34.17 psu) from Java Sea, where inter-leavings of salinity profiles are obviously seen between surface density of 22.0 σθ and 23.50 σθ. Estimation of turbulent vertical eddy diffusivity in this upper-thermocline are found strong with the order of 10−3 m2/s. It is suggested that energetic internal tidal waves may contribute significantly to the vertical mixing in this complex topographic region.
Design and analysis of multibeam communication satellite links operated at Ka Band Frequency in Indonesia
Authors: Qonita Aulia Haque , Muhtadin Nurul
Published: May 2019

In this paper, we design the link budget of communication satellite. This communication satellite is designed for Ka-Band Frequency for broadband communication in Non-Geostationary Orbit (NGSO) with altitude of 1200 km. The ability of this communication satellite depends on the strength of the signal and the amount of thermal noise. Ka-Band has wider bandwidth and higher data capacity but the drawback of this frequency is it is susceptible to rain attenuation in which Indonesia is an equatorial area that has high rainfall rate, so that the design of communication satellite in Ka-Band needs more consideration to determine satellite system parameter to keep the signal strength great. Indonesia is a wide archipelago country and satellite link design requires beam that can cover all Indonesia with great signal strength and multibeam antenna technology is one of solutions to overcome it. In this research, design and analysis of communication satellite is done using multibeam antenna. The main challenge of the design is to generate the link budget’s result to meet determined parameter. Iterative calculation in design must be used to find an effective link margin and bit rate of this communication satellite. The main result of this research is multi beam satellite provide better performance than single beam satellite in Ka band frequency. The use of BPSK modulation in multi beam satellite shows better performance than other modulation types.
Simulation of coding layer of telecommand based on the Consultative Committee for Space Data Systems recommendation
Authors: Nugroho M , Choiriyah I
Published: May 2019

Telecommand is a command sent to control a remote system or systems not directly connected to the place from which the telecommand is sent. In the telecommand process, there is a data processing process so that the command data that will be sent can be read / translated and processed accurately by the satellite. The Consultative Committee for Space Data Systems (CCSDS) provides recommendations for the telecommand process. CCSDS uses layering model to describe telecommand process, one of them is coding layer. This paper will talk about the simulation of coding layer of telecommand process based on CCSDS recommendation. The simulation involves randomization process, BCH encoding, and BCH decoding using MATLAB software. The result of this simulation shows encoding and decoding process successfully managed and produced data format which complies with CCSDS recommendation.
Development of a Nonradioactive Platelet Serotonin Uptake and Release Assay by Micro-Liquid Chromatography Tandem Mass Spectrometry Using Minimal Blood Volume
Authors: Chan Siaw Li , Yi Xin , Wysocki Emily , Bridgman Rachael , Gutierrez Jocelyn , Mikrut Krzysztof , Leung Edward Ki-Yun , Yeo Kiang-Teck J , Miller Jonathan L
Published: May 2019

Objectives

Analysis of platelet functional responses to stimuli is presently quite limited with respect to measurement of dense granule secretion. We sought to develop a nonradioactive assay of stimulated serotonin release using liquid chromatography tandem mass spectrometry (LC-MS/MS).

Methods

Citrated whole blood (200 μL) was incubated with deuterated serotonin (d45-HT). Following uptake by platelets, blood was diluted 10-fold and aliquots were incubated with platelet stimuli. Following stimulation, blood was further diluted, centrifuged, and supernatant was assayed for released d45-HT by micro-LC–MS/MS.

Results

This study demonstrated a broad linear range of 50 to 2,000 pg/mL d45-HT, with a total precision of less than 15.0% coefficient of variation at all quality control levels and a limit of quantitation of 50 pg/mL.

Conclusions

Quantification of d45-HT by micro-LC–MS/MS assay offers a highly sensitive, nonradioactive methodology for quantitating platelet serotonin uptake and dense granule secretion, requiring only small volumes of patient blood.