bluuebunny/crossref_metadata_2025 huggingface dataset:
Steady-state entanglement and heat current of two coupled qubits in two baths without rotating wave approximation*
Authors: Wang Mei-Jiao , Xia Yun-Jie
Published: June 2019

We study the steady-state entanglement and heat current of two coupled qubits, in which two qubits are connected with two independent heat baths (IHBs) or two common heat baths (CHBs). We construct the master equation in the eigenstate representation of two coupled qubits to describe the dynamics of the total system and derive the solutions in the steady-state with stronger coupling regime between two qubits than qubit–baths. We do not make the rotating wave approximation (RWA) for the qubit–qubit interaction, and so we are able to investigate the behaviors of the system in both the strong coupling regime and the weak coupling regime, respectively. In an equilibrium bath, we find that the entanglement decreases with the bath temperature and energy detuning increasing under the strong coupling regime. In the weak coupling regime, the entanglement increases with coupling strength increasing and decreases with the bath temperature and energy detuning increasing. In a nonequilibrium bath, the entanglement without RWA is useful for entanglement at lower temperatures. We also study the heat currents of the two coupled qubits and their variations with the energy detuning, coupling strength and low temperature. In the strong (weak) coupling regime, the heat current increases (decreases) with coupling strength increasing when the temperature of one bath is lower (higher) than the other, and the energy detuning leads to a positive (negative) effect when the temperature is low (high). In the weak coupling regime, the variation trend of heat current is opposite to that of coupling strength for the IHB case and the CHB case.
Group consensus of multi-agent systems subjected to cyber-attacks*
Authors: Gao Hai-Yun , Hu Ai-Hua , Shen Wan-Qiang , Jiang Zheng-Xian
Published: June 2019

In this paper, we investigate the group consensus for leaderless multi-agent systems. The group consensus protocol based on the position information from neighboring agents is designed. The network may be subjected to frequent cyber-attacks, which is close to an actual case. The cyber-attacks are assumed to be recoverable. By utilizing algebraic graph theory, linear matrix inequality (LMI) and Lyapunov stability theory, the multi-agent systems can achieve group consensus under the proposed control protocol. The sufficient conditions of the group consensus for the multi-agent networks subjected to cyber-attacks are given. Furthermore, the results are extended to the consensus issue of multiple subgroups with cyber-attacks. Numerical simulations are performed to demonstrate the effectiveness of the theoretical results.
Quantal studies of sodium

3
p
←
3
s

photoabsorption spectra perturbed by ground lithium atoms
Authors: Lamoudi N , Talbi F , Bouazza MT , Bouledroua M , Alioua K
Published: June 2019

The pressure broadening in the far wings, where the sodium Na (

3
p
←
3
s

) resonance line is perturbed by ground lithium Li (2s) atoms, has been theoretically analyzed. The NaLi potential–energy curves and the transition dipole moments are constructed by using a reliable ab initio data points to carry out the reduced-absorption coefficients

k

r

(
ν
,
T
)

. This quantum-mechanical investigation have demonstrated that the NaLi profile spectra show a satellite future in the red wing at wavelength λ =685 nm in the temperature range 4000 K–1.8×104 K. The computation could also exhibit a second satellite, in the blue wing, near the wavelength λ =574 nm beyond 6000 K and a third peak located at λ =490 nm which begins to appear at 1.8×104 K.
Monolithic all-fiber mid-infrared supercontinuum source based on a step-index two-mode As2S3 fiber*
Authors: Yao Jinmei , Zhang Bin , Hou Jing
Published: June 2019

We demonstrate efficient supercontinuum generation extending into mid-infrared spectral range by pumping a two-mode As2S3 fiber in the normal dispersion regime. The As2S3 fiber is fusion spliced to the pigtail of a near-infrared supercontinuum pump source with ultra-low splicing loss of 0.125 dB, which enables a monolithic all-fiber mid-infrared supercontinuum source. By two-mode excitation and mixed-mode cascaded stimulated Raman scattering, a supercontinuum spanning from

1.8
μ
m

to

4.2
μ
m

is obtained. Over 70% of the supercontinuum power is converted to wavelengths beyond

2.4
μ

m. This is the first experimental report with respect to the multimode mid-infrared supercontinuum generation in a step-index two-mode chalcogenide fiber.
Quantum density functional theory studies of structural, elastic, and opto-electronic properties of ZMoO3 (Z = Ba and Sr) under pressure
Authors: Tariq Saad , Mubarak AA , Saad Saher , Imran Jamil M , M Sohail Gilani S
Published: June 2019

In continuation of our recent report on molybdates [Appl. Phys. A
124, 44 (2018)], the structural, electronic, elastic, and optical properties of ZMoO3 (Z = Ba and Sr) molybdates are investigated under pressure (10 GPa–50 GPa) comprehensively by deploying the density functional theory. Our investigations show that the studied compounds exhibit stable cubic phase with metallic attributes. The thermodynamic parameters such as enthalpy of formation, Debye, and melting temperatures of the compounds are observed to increase with pressure. While the Grüninsen parameter and the coefficient of super-plastic deformation decrease as the pressure increases. Mechanical properties elucidate an increase in measured values of hardness, bulk, shear, and youngʼs moduli with pressure. Our results suggest that the studied compounds are useful in high pressure optoelectronic devices. The optical properties of BaMoO3 (BMO) and SrMoO3 (SMO) are computed for the radiation of up to 35 eV. The present compounds show beneficial optical applications in the anti-reflection coating, lenses, and the high avoiding solar heating applications in the variant applied pressure.
Analysis of displacement damage effects on bipolar transistors irradiated by spallation neutrons
Authors: Liu Yan , Chen Wei , He Chaohui , Su Chunlei , Wang Chenhui , Jin Xiaoming , Li Junlin , Xue Yuanyuan
Published: June 2019

Displacement damage induced by neutron irradiation in China Spallation Neutron Source (CSNS) is studied on bipolar transistors with lateral PNP, substrate PNP, and vertical NPN configurations, respectively. Comparison of the effects on different type transistors is conducted based on displacement damage factor, and the differences are analyzed through minority carrier lifetime calculation and structure analysis. The influence of CSNS neutrons irradiation on the lateral PNP transistors is analyzed by the gate-controlled method, including the oxide charge accumulation, surface recombine velocity, and minority carrier lifetime. The results indicate that the total ionizing dose in CSNS neutron radiation environment is negligible in this study. The displacement damage factors based on 1-MeV equivalent neutron flux of different transistors are consistent between Xi’an pulse reactor (XAPR) and CSNS.
Enhancing superconductivity of ultrathin YBa2Cu3O7-δ films by capping non-superconducting oxides*
Authors: Bo Hai , Ren Tianshuang , Chen Zheng , Zhang Meng , Xie Yanwu
Published: June 2019

In this study, we have explored the ways to fabricate and optimize high-quality ultrathin YBa2Cu3O7-δ
(YBCO) films grown on single-crystal (001) SrTiO3 substrates. Nearly atomic-flat YBCO films are obtained by pulsed laser deposition. Our result shows that the termination of SrTiO3 has only a negligible effect on the properties of YBCO. In contrast, we found that capping a non-superconducting oxide layer can generally enhance the superconductivity of YBCO. PrBa2Cu3O7, La2CuO4, LaMnO3, SrTiO3, and LaAlO3 have been examined as capping layers, and the minimum thickness of superconducting YBCO with capping is ∼2 unit cells–3 unit cells. This result might be useful in constructing good-performance YBCO-based field effect devices.
Topological superconductivity in a Bi2Te3/NbSe2 heterostructure: A review*
Authors: Zheng Hao , Jia Jin-Feng
Published: June 2019

Topological superconductors carry globally protected gapless boundary excitations, which are robust under local perturbations, and thus exhibit both fundamental and applicational importance. An unconventional pairing with p-wave symmetry, such as a nontrivial topology in the superconductor’s wavefunction, is required to generate a non-zero Berry phase. Until now, the Bi2Te3/2H–NbSe2 heterostructure has proven to be a practical way to realize a topological superconductor in real materials. This complex system, where odd numbers of spin-momentum locked Dirac cone surface states on the topological insulator Bi2Te3 become superconducting, induced by the proximate effect from the underlying s-wave superconductor 2H–NbSe2, realizes an effective two-dimensional (2D) spinless

p

x

+
i

p

y

topological superconductor. In this review article, we summarize the recent experimental progress of the successful synthesis of Bi2Te3/2H–NbSe2 heterostructures using molecular beam epitaxy, determining the thickness limit of the heterostructure, detecting the long thought Majorana quasiparticle inside a magnetic vortex core state by means of scanning tunneling microscopy and demonstration of the unique spatial and spin properties of a Majorana zero mode.
Hard carbons derived from pine nut shells as anode materials for Na-ion batteries*
Authors: Guo Hao , Sun Kai , Lu Yaxiang , Wang Hongliang , Ma Xiaobai , Li Zhengyao , Hu Yong-Sheng , Chen Dongfeng
Published: June 2019

Hard carbons as promising anode materials for Na-ion batteries (NIBs) have captured extensive attention because of their low operation voltage, easy synthesis process, and competitive specific capacity. However, there are still several disadvantages, such as high cost and low initial coulombic efficiency, which limit their large-scale commercial applications. Herein, pine nut shells (PNSs), a low-cost biomass waste, are used as precursors to prepare hard carbon materials. Via a series of washing and heat treatment procedures, a pine nut shell hard carbon (PNSHC)-1400 sample has been obtained and delivers a reversible capacity of around 300 mAh/g, a high initial coulombic efficiency of 84%, and good cycling performance. These excellent Na storage properties indicate that PNSHC is one of the most promising candidates of hard carbon anodes for NIBs.
Design and fabrication of 10-kV silicon–carbide p-channel IGBTs with hexagonal cells and step space modulated junction termination extension*
Authors: Wen Zheng-Xin , Zhang Feng , Shen Zhan-Wei , Chen Jun , He Ya-Wei , Yan Guo-Guo , Liu Xing-Fang , Zhao Wan-Shun , Wang Lei , Sun Guo-Sheng , Zeng Yi-Ping
Published: June 2019

10-kV 4H–SiC p-channel insulated gate bipolar transistors (IGBTs) are designed, fabricated, and characterized in this paper. The IGBTs have an active area of 2.25 mm2 with a die size of 3 mm × 3 mm. A step space modulated junction termination extension (SSM-JTE) structure is introduced and fabricated to improve the blocking performance of the IGBTs. The SiC p-channel IGBTs with SSM-JTE termination exhibit a leakage current of only 50 nA at −10 kV. To improve the on-state characteristics of SiC IGBTs, the hexagonal cell (H-cell) structure is designed and compared with the conventional interdigital cell (I-cell) structure. At an on-state current of 50 A/cm2, the voltage drops of I-cell IGBT and H-cell IGBT are 10.1 V and 8.3 V respectively. Meanwhile, on the assumption that the package power density is 300 W/cm2, the maximum permissible current densities of the I-cell IGBT and H-cell IGBT are determined to be 34.2 A/cm2 and 38.9 A/cm2 with forward voltage drops of 8.8 V and 7.8 V, respectively. The differential specific on-resistance of I-cell structure and H-cell structure IGBT are

72.36

m
Ω
·

cm

2

and

56.92

m
Ω
·

cm

2

, respectively. These results demonstrate that H-cell structure silicon carbide IGBT with SSM-JTE is a promising candidate for high power applications.
Optical properties of two-dimensional square lattices with smooth and randomly rough surfaces that include dispersive left-handed materials
Authors: Puente-Díaz L E , Castillo-Gallardo V , Pérez-Aguilar H , Mendoza-Suárez A
Published: June 2019

The study of photonic crystals (PCs) is very importance for the development of new optical technologies. An interest in the investigation of PCs is the search of totally optical control of information in a circuit, with the idea of developing new technological applications that have great advantages over conventional electronic devices in the miniaturization of circuits. In the present work, we show a numerical study of the electromagnetic response of two-dimensional square lattices such as finite photonic structures formed by cylinders embedded in air and air holes in a finite plate composed of metamaterial. We applied a numerical technique known as Integral Equation Method (IEM) to calculate the optical response by calculating reflectance and transmittance as a function of the angle of incidence of finite systems proposed. The calculations were performed by varying the filling fractions and introducing a random roughness on the surfaces of the cylindrical inclusions that form our proposed systems, for the transverse magnetic field (TM) polarization. The results obtained show that the random roughness on the surfaces of the cylindrical inclusions affects their reflective and transmissive properties of two-dimensional square lattices. This is an important result to consider in manufacturing of finite two-dimensional square lattices, despite the existence of a well-developed technology for the manufacture of surfaces. These structures can be used, for example, for the development of filters, mirrors and lenses.
Excitation of surface plasmon polaritons in photonic crystal waveguides that involve dispersive metamaterial
Authors: Medina-Magallón J E , Pérez-Aguilar H , Zhevandrov-Bolshakova P , Mendoza-Suárez A
Published: June 2019

Plasmonics is an area of research that deals mainly with the study of the properties of surface plasmon (SPs) that are collective oscillations of the electron gas in a metal. That is, when the light waves couple with the electronic oscillations, they form a new quasi-particle called the surface plasmon polariton (SPP) that propagates through the surface of the nanometer-sized structure. In this work, we present a numerical study of a photonic crystal waveguide (PCW) composed by an array of cylindrical inclusions with smooth surfaces of dispersive metamaterial. The numerical technique we have used to perform the calculations is known as the “Integral Equation Method”. First, the numerical results are presented of a PCW of infinite length formed by an array of inclusions of dispersive metamaterial (LHM), showing that there is the presence of an SP mode at the frequency ωr
= 0.7519. Subsequently, some numerical results of the optical response are presented when the PCW is of finite length, showing the presence of the same surface mode around of ωr
= 0.7510. This excitation of the surface plasmon polariton in the proposed waveguide can be another alternative for the development of innumerable applications in several fields of science and technology ranging from biomedicine to telecommunications.
Hydrogen adsorption in Metal-Organic Frameworks Cu-BTC and Fe-BTC:A comparative theoretical study.
Authors: Castañeda A , Jurado M , Matz O. , Calatayud M , Rojas E , Maubert A
Published: June 2019

In order to obtain a hydrogen storage system that is cost-effective, safe and energy-viable, in this work we studied the adsorption process of different sites and configurations of the hydrogen molecule in both MOF HKUST-1 and FeBTC structure. For the computational study was used the Ab initio simulation package from Vienna (VASP) with the GGA PBE functional in an SBU of 672 atoms. The exposed metal sites were found to be the best interaction site for the hydrogen molecule. In this work showed adsorption energy of -0.114 eV and -0.93 eV for HKUST-1 and FeBTC, respectively. This work also evidences the modifications of the atomic positions when the hydrogen molecule interacts with the MOF and the network energy.
Viscoelastic moduli of ferrofluid
Authors: Peredo-Ortíz R , Hernández-Contreras M
Published: June 2019

A statistical mechanics model is proposed for the storage and dissipative modulus of diffusion microrheology valid at the regime of linear flow without external magnetic or electric perturbations. A comparison of these moduli with similar viscoelastic properties obtained from Langevin dynamics simulations yields qualitative agreement at low-frequency responses.
Automatic Tablet Machine
Authors: Aragón-Gonzáles G , Barragán-Santiago I , Cano-Blanco M , León-Galicia A , Morales-Gómez J R
Published: June 2019

A Mexican manufacturing plant, whose main product is deodorant tablets for domestic and commercial use, requested the design, construction, and start up of an automatic machine to make 3 600 deodorant tablets per hour of Paradichlorobenzene (PDB). The tablets should have a density no less than 1 400 [kg/m3] with a weight variation of 5% maximum. To design the machine, it was necessary, as a first step, to make an experimental study to determine the power needed to reach the required density and to determine the process characterization to obtain the general characteristics of the machine. Movements and compaction forces were performed by means of electro-pneumatic and electro-hydraulic technologies. The specification of the logic controller of the machine was realized by means of Grafcet to allow efficiency and accuracy. The result of the work generated a versatile, efficient machine with a robust control system.
Heat Transfer Intern Coefficient Determination in the Process of Solar Still
Authors: Chávez S , Terres H , Lizardi A , López R , Lara A
Published: June 2019

In this work, a study of internal heat transfer coefficients is performed in a solar still of a slope is presented, when it operated with brine. The estimate is based on the experimental observation of the solar still for 4 different initial volumes (2, 4, 6 y 8 L), under the climatic conditions of the city of Mexico. The internal coefficients to evaluate are: convection, evaporation and radiation through the use of the thermal model proposed by Kumar and Tiwari. As a result it was found that the internal coefficient more representative in the process of solar distillation is the evaporation (h

E,w-g
), reaching a maximum of 30 W/m2 K, the coefficients of convection (h

c,w-g
), and radiation (h

R,w-g
),attained values of 2.5 W/m2 K and 4 W/m2 K respectively. It was also noted that as the initial volume of brine increases, the internal heat transfer coefficients decrease.
The outflow of granular material from orifices of thin vertical sidewalls
Authors: Serrano D A , Hernández-Juárez J , López-Villa A , Medina A , Vargas C A , Pliego M
Published: June 2019

In this work we report experiments carried out to describe the features of the mass flow rate of dry cohesionless granular material that flows, only due to gravity, out from circular orifices at the sidewall of silos with thin wall thickness, w. This study shows that the classical Hagen’s correlation for the mass flow rate is essentially correct for this case. Finally, we show graphically, in a three-dimensional plot, the evolution of the flow rate for continuous variations of the parameters D and w
Angular dependence of the optical reflectance in two-dimensional Si-ZnO photonic crystals
Authors: Murillo J G , Carrillo-Vázquez V. M. , Gallardo Víctor Castillo , Téllez Villaseñor Miguel Ángel , Aguilar Héctor Pérez , Medina-Vázquez José Antonio , González Ramírez Evelyn Yamel , Herrera G. , Duarte-Moller A.
Published: June 2019

In this work, we present an experimental study of the angular dependence of the optical reflectance in two 2-dimensional photonic structures, built on a silicon substrate coated with a ZnO thin film. Photonic structures studied describe a regular square lattice with a lattice constant a = 1.05 μm and circular air holes with a radius r = 0.63a. Additionally, one of these photonic structures contains a pattern of nine quasi-circular micro-cavities embedded in a regular square lattice photonic crystal, describing a secondary square lattice. A comparison of the optical reflectance of the two photonic structures as a function of the incidence angle for transverse magnetic polarization mode in the visible (Vis) and near-infrared (NIR) ranges of the electromagnetic spectrum was accomplished. Results obtained revealed a strong angular dependence of the reflective optical properties of the two 2-dimensional photonic structures on the illumination incidence angle. The photonic structure with the array of resonant optical cavities presented a very unusual behavior regarding the reflectance of the substrate, this because its reflectance described specific modulations dependent on the incidence angle of illumination.
Fractional convolution and nonlinear operations applied to the image encryption
Authors: Vilardy Juan M. , Torres Cesar O. , Jimenez Carlos
Published: June 2019

We use the fractional convolution, nonlinear operations and random phase masks (RPMs) in order to encrypt images. The definition used in this paper of the fractional convolution is based on the fractional Fourier transform (FrFT). The amplitude and phase truncation are nonlinear operations that allow to select a specific information of a complex-valued image. The encryption and decryption systems are based on the double random phase encoding (DRPE). At the beginning of the encryption process, the image to encrypt is encoded in phase. The rest of the encryption and decryption process use two RPMs, the fractional convolution and the amplitude and phase truncation operations in a sequential way in order to get the encrypted and decrypted image. The amplitude and phase truncation and the phase encoding are nonlinear operations that improving the security of the encrypted image, because the obtained key space of the proposed encryption process is very larger. The fractional order of the FrFT introduces a new key for the security system and the encrypted image of the proposed encryption system is a real-valued image. The encryption-decryption system has five security keys. All these five keys with their correct values are necessary in the decryption process with the purpose of obtaining the original image that was encrypted in the encryption process.
Electrical recognition of solvent liquids and particles in suspension with needle-plane electrodes
Authors: Mata-Hernández G , Guadarrama-Santana A
Published: June 2019

We report a measurement methodology to identify solvent liquids and the presence of suspended nanoparticles with needle-plane capacitive electrodes. Preliminary results were obtained with a low noise measurement system detecting differential electric signals of two needle-plane devices, sensing and compensating respectively. A solvent drop of 3 μl volume is placed between electrodes of the sensing device where electric field perturbations are due to the liquid evaporation process and registered as temporal electric signals. Low noise differential measurement system reduces parasitic capacitances present in the sensing device to a minimun value in order to obtain just the temporal capacitance of the liquid evaporation process, presenting a base noise around 0.15 [fF / √Hz]. The results show that different liquid samples can be recognized electrically with just 3 μl volume drop, analysing its temporal signal shape, amplitude and evaporation time.
Measurement of hydrostatic pressure using a hollow bottle microresonator
Authors: Avila D. A. , Horta S. D. , Torres C. O.
Published: June 2019

In this paper, we report the experimental results of the design and manufacture of a device in the form of a hollow bottle manufactured from a polymer for the measurement of hydrostatic pressure of microfluids in microcavities. The fabricated device bases its operation on the optical resonances of a capillary optical microresonator that couples the light coming from the evanescent field of an optical fiber taper with a central diameter in the range of 3-5 μm, exciting the resonant optical modes WGMs inside the cavity. The microcavity was manufactured using a heating-pressurization technique by a system built to measure which allowed reaching a minimum wall thickness in the central region of the order of 19.78 μm with a sensitivity of the order of 0.5567 nm/bar.
Database for the interpretation of phonocardiograms
Authors: Granados S J , Tavera R F , Hernández L RT , Cid R A , Velázquez A JM , López GG , González R AM
Published: June 2019

Using LabVIEW software, we built a set of images corresponding to cardiac sounds associated to diagnosed cardiac diseases. This constitutes an image database which facilitates phonocardiograms interpretation, also we made the correlation with diseases and the possible causes.
Climate change and air pollution: the connection between traffic intervention policies and public acceptance in a local context
Authors: Weiand Laura , Schmitz Seán , Becker Sophia , Niehoff Norman , Schwartzbach Frank , von Schneidemesser Erika
Published: June 2019

Urban mobility is the main source of air pollution in Europe and accounts for 25% of greenhouse gas emissions. In order to address this, a range of interventions and policies are being implemented across major European cities and studies in sustainable urban transport have proliferated. One such mitigation strategy involves redesigning urban form through ‘hard’ traffic policies, with a view of decreasing emission levels and therefore mitigating the effects of air pollution and climate change. However, efforts to assess public response to such interventions and the effectiveness of policy instruments in promoting sustainable travel in cities remain sparse. The city of Potsdam, Germany implemented a trial traffic measure aimed at reducing motorized traffic and promoting the use of bicycles and public transport systems. This study analysed data from 3553 survey participants who responded to a survey conducted prior to the implementation of the traffic measure. We aimed to identify mobility behaviours and underlying attitudes within the context of a ‘hard’ policy instrument, in order to obtain insight into the opportunities to more effectively define policy priorities that improve air quality and upscale climate mitigation. An exploratory cluster analysis identified four groups, characterised by mobility habits, their attitudes towards the measure, and general level of environmental concern. By identifying and understanding the differing attitudes and perceptions across population groups we are able to highlight group-specific barriers and opportunities, as well as potential transition pathways to encourage more sustainable transportation use. This study exemplifies how context can help to further shape mobility group typologies, identify policy-related priorities useful for decision-makers and assess the feasibility of policy instruments to facilitate a transformation towards more sustainable cities.
Noise reduction in near infrared-based glucose concentration measurement sensor
Authors: Prawiroredjo K , Julian E S , Tjahjadi G
Published: June 2019

This paper describes the method of measuring glucose concentrations in solution using near infrared light (NIR) and photodiode sensor. A sensitive and accurate non invasive blood glucose level sensor is our main concern in designing this device. The sensor consists of a transimpedance amplifier, a notch filter and a low pass filter to reduce high frequency noise and 50 Hertz noise from the power line induction. Light Emitting Diode (LED) with 1450 nm wavelength is used as a light source and a photodiode is used as a sensor to sense this wavelength. The NIR light received by the photodiode after passing glucose solution is converted to voltage signal and filtered to determine the output voltage. The measurement results show that the filters reduced the AC voltage or noise signal under 100 mV and the DC voltage tended to decrease as glucose concentration increase until 700 mg/dL.
A New Geological Map of Formation Distribution on Southern Part of South China Sea:; Natuna Island, Indonesia
Authors: Kausarian H , Lei S , Lai G T , Cui Y , Suryadi A
Published: June 2019

Natuna Island is located at the outer part of the Indonesian territory and also as the end part of South China Sea at the south. Natuna consists of the islands that are surrounded by coral reefs and composed by sedimentary rock and sediment surface (alluvium). Natuna is a part of the Sunda group (Sundaland) which evolved through tectonic events (on the east) and volcanic activity, the formation of this island occurred in late Triassic time. Survey (field observation) applied for geological mapping by sample analyzing and tracking using handheld GPS. This research uses Natuna geological map from geological research and development center of Indonesia in 1994 with the scale of 1: 250,000 and interpretation of satellite imagery from the year 2015 with scale 1: 50,000 as reference material. The new spreading of formation distribution is seen in the Raharjapura Formation which has the lithology of alternating sandstone and repeating limestone spread across the north to the southwest and dominates the arrangement of formations in this island. Another new spreading occurs in the Eastern for Pengadah Formation, this formation has conglomerate lithology, sandstone aligned with Raharjapura’s formation. Hydrocarbon outcrop also found in the northeastern region of Natuna, this is a common thing because the Natuna islands are famous for its natural wealth of oil and gas. The final result is an updated geological map showing significant changes to the distribution of rock formations and alluvium and also propose the idea for developing this island as the vital area for Indonesian territory border.
Molecular Reidentification of Endophytic Fungus LBKURCC40 Isolated from Dahlia’s Tuber (Dahlia Variabilis) Using the Sequence of ITS rDNA
Authors: Suraya Nabella , Piska Finna , Pratiwi Nova Wahyu , Ardhi Aulia , Saryono
Published: June 2019

Endophytic fungus LBKURCC40 isolated from dahlia tubers (Dahlia variabilis) was morphologically and molecularly identified. Molecular identification was carried out using ITS4 and ITS5 primers, furthermore, the homology level of LBKURCC40 isolates was checked using BLAST program and the suitability of BLAST results was tested with the TrichOKEY program. The results of showed that LBKURCC40 isolates were identified as Trichoderma asperellum with a homology level of 99%. Phylogenetic analysis was carried out with N-J tree bootstrap test with 10,000 repetitions, and LBKURCC40 isolate was obtained to have the closest kinship to Trichoderma asperellum strain Tr266B.
Utilization of Molasses to Produce Lactic Acid by Using Lactobacillus Delbrueckii and Lactobacillus Plantarum
Authors: Nurkhamidah S , Altway A , Susianto  , Rahmawati Y , Taufany F , Hendrianie N , Ni’mah H , Gunardi I , Zulaikah S , Ningrum E O , Nyamiati R D , Ramadhani A
Published: June 2019

Molasses is the final liquid from the process of crystallization of sucrose in a sugar factory. In general this liquid is only disposed to the surrounding environment or used as a fertilizer mixture. However, this fluid still contains glucose that can be fermented into lactic acid. Lactic acid is a water-soluble compound commonly used in food, pharmaceutical and chemical industries. Through the polymerization process, lactic acid changes into polylactic acid (PLA) which is a biodegradable plastic. In general, PLA is made from corn. If PLA can be synthesized from molasses, it can reduce the use of corn as a raw material for making PLA and reduce waste in the sugar industry. This study aims to determine the optimal conditions of lactic acid fermentation by using sugarcane drops from Tulung Agung as a source of glucose and its purification so that it can obtain high levels of lactic acid. The results showed that fermentation with Lactobacillus plantarum could produce more lactic acid with faster fermentation time than the fermentation using Lactobacillus delbrucckii with a concentration of lactic acid 19.68 g/L.
Characterization of Zeolite A from Coal Fly Ash Via Fusion-Hydrothermal Synthesis Method
Authors: Wulandari W , Paramitha T , Rizkiana J , Sasongko D
Published: June 2019

Zeolite A has been successfully synthesized from coal fly ash by using fusion followed by hydrothermal method. This paper describes the characterization of zeolite A. The effects of hydrothermal time, Si/Al molar ratio, and alkalinity in the converting coal fly ash to zeolite A were also investigated. The coal fly ash was obtained from a local power plant at East Java, Indonesia and contained major oxides such as SiO2 (18.60 wt%), Al2O3 (7.18 wt%), Fe2O3 (40.20 wt%), CaO (25.20 wt%). The fusion hydrothermal method consists of the following steps: pre-treatment, fusion of coal fly ash with sodium hydroxide, aging, and hydrothermal process. The synthesized material was characterized by using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), and specific surface area analytical method. The results show that the products contain zeolite A as the major phase, while the highest specific surface area of zeolite A is 37.121 m2/g. It implies that zeolite A as a higher value added product can be obtained from a solid waste/by-product of power plant, which has wide range applications, including for ion exchange and heavy metal adsorbent from waste water.
Natural Rubber Powder Production from Latex
Authors: Abidin A Z , Winartha N R , Rahardi I , Trirahayu D A
Published: June 2019

Natural rubber-based products are widely used in everyday life. There are three types of upstream processed natural rubber, that are crumb rubber, conventional rubber, and concentrated latex. Latex is easily damaged by clotting and contains 35-40% w/w of water so that the packaging volume is relatively large and inefficient in transportation. Latex also contains ammonia as an anti-clotting agent so the packaging must be special to prevent unpleasant odour. This study aims to create a pilot plant of the spray drying latex from simulation results then test the performance, evaluate the performance test results, as well as making improvements to the production of rubber powder. The steps of this research are data collection for spray dryer design, design verification, construction of spray dryer, spray dryer appliance testing, and characterization of rubber powder produced. The heating system used in the spray dryer is LPG gas-fired furnace. Testing is done by varying the spray dryer drying air temperature of 120°C, 150°C, and 180°C, the water content of the feed latex 70% and 80% w/w, as well as non-stick material such as talc powder and MgO. Rubber powder characterized by water content with digital tools moisture meter and analysed spectra with Fourier Transform Infrared Spectroscopy (FTIR). The results showed the optimum operating conditions for the production of natural rubber powder is drying air temperature of 150°C and the water content of the feed latex 80% w/w. Natural rubber powder produced contains 10 to 13% w/w water but still sticky so that the powder grains stick to each other. The FTIR spectrum analysis of natural rubber powder products show similarity with bonding group of polyisoprene natural rubber compound. Natural rubber powder product can also be used as a substitute for crumb rubber.
Melt Rheological Properties of Polypropylene/Clay Nanocomposites Prepared from Masterbatch: Effect of Nanoclay Loadings and Reprocessing
Authors: Chafidz A. , Ma’mun S. , Fardhyanti D. S. , Kustiningsih I. , Hidayat A.
Published: June 2019

In the present work, polypropylene (PP) and nanoclay in the form of masterbatch were melt compounded using a co-rotating twin screw extruder to fabricate polypropylene (PP)/clay nanocomposites. PP/clay nanocomposites samples with four different nanoclay loadings (i.e. 0, 5, 10, and 15 wt%) were prepared. Additionally, to study the effect of reprocessing on the properties of the nanocomposites, the melt compounding process was carried twice/recycle (i.e. 1st cycle and 2nd cycle). The surface morphological of the nanocomposites and their melt rheological behavior were investigated using a Scanning Electron Microscopy (SEM) and an oscillatory rheometer, respectively. The SEM micrographs showed that the nanoclay was well distributed in the polypropylene matrix for both 1st and 2nd cycles. While, the dispersion state of the nanoclay (either intercalated or exfoliated) could not be observed due to the limitation of the apparatus. Additionally, the melt rheological analysis results showed that the complex viscosity, |µ*| of all nanocomposites samples (for both 1st and 2nd cycles) were higher than the neat PP and the |µ*| also increased with the increase of nanoclay loadings. However, the 2nd cycle showed a slightly higher improvement of |µ*| compared to the 1st cycle, and the improvement of |µ*| was more prominent at lower angular frequencies (e.g. 0.1, 1, 10 rad/s) than at higher ones (e.g. 100, 500 rad/s).
Mixing Solvent’s Effect to the Characterization and Performance Cellulose Acetate/Polyethylene Glycol Membrane
Authors: Nurkhamidah S , Rahmawati Y , Taufany F , Fahrizal Y E , Ramadhan I H
Published: June 2019

The need for clean water continues to increase. Therefore, it is necessary to find an alternative for the get of clean water. One way is desalination process using membrane. Cellulose Acetate/Polyethylene Glycol (CA / PEG) membrane is one type of membrane that can be used for desalination process. Several studies on the manufacture of CA / PEG membranes have been performed, but have not yet produced a good performance membrane. Therefore in this research was synthesize CA/PEG/mixing solvent membrane using Acetone – THF/Acetone – DMF as the solvents at ratio 100-0, 90-10, 70-30, 50-50 (%volume) each and PEG as the additive vary PEG 200 and 400. CA/PEG/mixing solvent membrane characteristics are tested. The results showed that the hydrophilicity of mixing solvent method using Acetone-DMF (50:50) increase water content up to 375.86% and Acetone-THF (50:50)’s water content increase up to 177.10% with additive PEG 200, and for PEG 400 as additive showed that the hydrophilicity of mixing solvent method using Acetone-DMF (50:50) increase water content up to 503,86% and Acetone-THF (50:50)’s water content decrease from 173,28 % till 119,23%, as THF content increase.
Optimization of LNG Logistics System to Meet Gas Supply at Gresik LNG Receiving Terminal
Authors: Raharjo M , Sudibandriyo M
Published: June 2019

The construction of Gresik LNG receiving terminal is aimed to fulfil the 109 MMSCFD (0.87 MTPA) gas requirement for combined-cycle power plant (PLTGU) Jawa-3 which is integrated with LNG Gresik Terminal. There are several potential LNG plants in Indonesia and abroad that can be the source of gas for Gresik LNG Terminal. Each of these LNG plants has varying gas price and distance to Gresik. The modelling of the LNG logistics system for Gresik LNG Terminal was built to illustrate the LNG supply chain from the LNG plants to Gresik LNG Terminal and several supply scenarios will be proposed. The built model is linear and optimized by using linear programming. Linear programming involves the determination of objective functions, decision variables and constraints. The optimization of the logistics system aims to obtain the cheapest gas supply cost for Gresik LNG receiving terminal. The result shows that the cheapest gas supply cost is obtained through direct supply scenario with gas source from domestic and abroad with combination of delivery from Bontang equal to 0.34 MTPA (40 %) with 12 shipments, Tangguh equal to 0.26 MTPA (30 %) with 9 shipments, and Bintulu Malaysia equal to 0.26 MTPA (30 %) with 9 shipments.
A Sustainability assessment of biogas plant based on fruit waste in Indonesia: case study of Biogas Plant Gamping, Yogyakarta
Authors: Marendra F , Prasetya A , Cahyono R B , Ariyanto T
Published: June 2019

The production of biogas by anaerobic digestion (AD) from fruit waste and then converting biogas to electricity is an innovative approach in the development of renewable energy. To study the sustainability of the process, it important to analysis the environ-socio-economic benefits of the technology. In this study, the life cycle sustainability assessment (LCSA) were carried out in a fruit waste biogas plant system, which located in the Gemah Ripah Central Fruit Market in Indonesia. The AD system was designed for 4000 kg/day feed and supplies 148.5 kWh/day electricity. The results of assessment of environmental, economic and social aspects are 5.00 (very good), 3.00 (moderate), and 4.00 (good). This study indicates that biogas plant from fruit waste has a significant advantage for environment, economic, and society. Overall, the sustainability of BPG is in the category of very good (grade I) with a value 4.11 from maximum value of 5.
Effect of Biomass Composition and Co-pyrolysis Retention Time on Reduction of Non-neutral CO2 Emission from Combustion of Hybrid Coal in Power Plant
Authors: Handoko S , Wulandari W , Rizkiana J , Ridha M A , Prasetyo H A , Sasongko D
Published: June 2019

Indonesia’s lignite coal and sawdust production are 131,05 and 11,82 million tonnes, respectively, which are potential to become raw material of hybrid coal through co-pyrolysis. Hybrid coal utilization will reduce non-neutral CO2 emission, a part of CO2 emission released from combustion of biomass. The aim of this study is to determine the effects on biomass composition and co-pyrolysis retention time on reduction of non-neutral CO2 emission from combustion of hybrid coal in power plant. Co-pyrolysis was conducted in a vertical tubular furnace under an inert condition in atmospheric pressure and temperature 300° C. Biomass composition and co-pyrolysis retention time was varied from 20 to 40 %-mass and from 30 to 90 minutes, respectively. Hybrid coal was characterized with proximate, ultimate and calorific value analysis. The result of analysis was used as an input on simulation to determine reduction of non-neutral CO2 emission on hybrid coal combustion in power plant. An increase in co-pyrolysis retention time (CRT) from 30 to 90 minutes increases the CO2 emission from 13.25 to 13.30 %-vol. While increase in biomass composition from 20 to 40 %-mass reduce CO2 emission from 13.18 to 12.81 %-vol. Non-neutral CO2 emission reduction rises from 24.22 to 26.86 % along with the increased of biomass composition from 20 to 40 %-mass. Average of non-neutral CO2 emission reduction is about 26.30 % in all variation. CO2 emission of hybrid coal as fuel for power plant increased along with the increased of co-pyrolysis retention time (CRT), which was about 780-830 kg CO2/MWh. The highest CO2 emission was achieved from co-pyrolysis product hybrid coal utilization with 30 %-mass of biomass composition.
Fabrication of Interlayer-free P123 Caronised Template Silica Membranes for Water Desalination: Conventional Versus Rapid Thermal Processing (CTP vs RTP) Techniques
Authors: Elma M , Setyawan H , Rahma A , Pratiwi A E , Rampun E L A
Published: June 2019

This work demonstrates the comparison techniques between conventional and rapid thermal processing (CTP Vs RTP). It is to fabricate the interlayer-free P123 carbonised template silica membranes. The aim of this work is to understand the performance of fabricated membranes for water desalination. The silica sols pH 6 were prepared from a two acid-base catalyzed sol gel method by applying tetraethyl orthosilicate (TEOS) as the precursor. Triblock copolymer of Pluronic P123 was used as the templating agent and mixed homogenously with silica sols. The mixtures were calcined in two method called CTP and RTP. CTP is a slow calcination and takes 4 hours with 1 °C min-1 for dwelling time. On the other hand, RTP is rapid technique calcined in air (1 h without dwelling time). CTP confirms higher surface area (50 % higher), porosity (34 % higher) and thinner (60 %) than RTP. RTP technique is supposed to save time, energy and cost during membranes fabrication.
Microfiltration of Oily Waste Water: A Study of Flux Decline and Feed Types
Authors: Sutrisna P D , Candrawan J , Tangguh W W
Published: June 2019

In recent years, membrane separation techniques gain an increasing interest to be applied in many industrial separation processes, such as the separation of produced water in petroleum industry and the treatment of used oil and used cooking oil. Used oil and used cooking oil consist of suspended solids in addition to emulsion. Both ultrafiltration and microfiltration have been used to separate oil from water. The challenges of oil-in-water emulsion separation include the possibility of big oil drops deforming through the slot or pore of membrane thus reduce the oil rejection. In addition, concentration polarisation and fouling phenomena are considered as negative attributes for membrane performances. This research applied flat sheet microfiltration membranes to treat used oil and used cooking oil. The performances of membranes in terms of flux reductions were evaluated and analysed using filtration model. Experimental results showed the decline of permeate flux with time indicating the formation of polarisation layer on the surface of the membrane. In addition, complete blocking and deep bed filtration explained the flux behavior of used oil and used cooking oil filtration, respectively.
Lignocellulosic Properties of Coffee Pulp Waste After Alkaline Hydrogen Peroxide Treatment
Authors: Pudjiastuti L , Iswanto T , Altway A , Ningrum E O , Widjaja T
Published: June 2019

The effect of alkaline hydrogen peroxide (AHP) treatment on reducing lignin content in coffee pulp waste (CPW) was investigated to increase the digestibility and accessibility of cellulose during production of valuable products by enzymatic and biological process. Hydrogen peroxide (H2O2) at various concentrations (2.5, 5, and 7.5% (w/w of substrate)) was mixed into 10% (w/v) of CPW-NaOH solution at 35 °C for 24 h with pH 11.5. The concentration of lignocellulosic content was investigated. The characteristic of crystallinity index, functional groups, and surface morphology of CPW at before and after the treatment have been observed using XRD, FTIR, and SEM analysis, respectively. The results showed that the highest lignin removal was achieved at the addition of 7.5% H2O2which decreased from 16.85% to 8.5%. The concentration of cellulose and hemicellulose in CPW increased from 53% to 64% and 11% to 24%, respectively. The crystallinity index of AHP-treated CPW has increased from 30.83% to 42.08%. A surface morphological destruction on the CPW was getting worse as along with the increase of H2O2concentration. This would be useful to increase the porosity of biomass to give cellulose accessibility by enzyme for further processes.