bluuebunny/crossref_metadata_2025 huggingface dataset:
Geometric phase in Brillouin flows
Authors: Rax Jean-Marcel , Gueroult Renaud
Published: December 2019

A geometric phase is found to arise from the cyclic adiabatic variation of the crossed magnetic and electric fields which sustain the Brillouin rotation of a plasma column. The expression of the gauge field associated with this geometric phase accumulation is detailed. The physical origin of this phase is shown to be the uncompensated inductive electric field drift that stems from magnetic field cyclic variations. Building on this result, the effect of a weak, periodic and adiabatic modulation of the axial magnetic field on the particle guiding center drift motion is demonstrated to be equivalent to that of a perpendicular electric field, allowing the study of the gauge induced Brillouin flow through a geometrically equivalent linear radial electric field. This finding opens new perspectives to drive plasma rotation and hints at possible applications of this basic effect.
Modeling and simulation of a single-mode multiphase Richtmyer–Meshkov instability with a large Stokes number
Authors: Meng Baoqing , Zeng Junsheng , Tian Baolin , Zhou Rui , Shen Weidong
Published: December 2019

This study focuses on the effects of a large Stokes number (St) on the perturbation growth in linear and nonlinear stages of a Richtmyer–Meshkov instability (RMI) in a gas-particle system, which to the best of our knowledge has not been previously reported. A linear growth model is developed by linear stability analysis and numerically verified by the compressible multiphase particle-in-cell (CMP-PIC) method. Additionally, the RMI growth characteristics in the nonlinear stage are also investigated by CMP-PIC. For the linear growth model, two major differences characterize the effects of a large St. The first one is that an RMI with a large St, which performs significantly different from the RMI with a small St, is induced and driven only by the density difference of the gas-phase and totally independent of particle density. Second, due to the significant momentum coupling effects between gas and particle phases, which govern the gas-particle flow, the growth rate experiences exponential decay, even in the linear RMI stage. The decay behavior performs markedly different from any previous RMI models, especially those of the original single-phase RMI and the gas-particle RMI with a small St. Notably, in the nonlinear stage of the RMI with a large particle volume fraction, the decay effects are much more pronounced and lead to a fall in the growth rate to almost zero, which is not found in any other type of RMI. These findings offer the possibility to develop a new method to control the development of hydrodynamic instability.
Thermal compatibility properties of C6F12O-air gas mixture with metal materials
Authors: Zhang Xiaoxing , Wang Yufei , Li Yi , Li Yalong , Ye Fanchao , Tian Shuangshuang , Chen Dachang , Xiao Song , Tang Ju
Published: December 2019

C6F12O (heptafluoroisopropyl pentafluoroethyl ketone) has been considered as a potential eco-friendly gas insulating medium to replace SF6, the most potent greenhouse gas, used in medium-voltage equipment. In this paper, we explored the compatibility between the C6F12O-air gas mixture and metals such as copper and aluminum to evaluate the long-term behavior of the new gas. Aging tests for the C6F12O-air gas mixture and metal were conducted, and the composition as well as the microstructure was analyzed. It was found that the interaction between C6F12O-air and copper results in the decomposition of C6F12O and corrosion of copper. Several by-products including CO2, C3F6, C4F8O, and C6F12 can be detected. Obvious color modifications and corrosion points exist after interaction. The compatibility between C6F12O-air and aluminum is superior to that between C6F12O-air and copper. Their interaction did not lead to the corrosion of aluminum. As for engineering applications, anticorrosion measures should be taken on copper to avoid the occurrence of negative chemical interactions.
Demonstration of low loss
β
-Ga2O3 optical waveguides in the UV–NIR spectra
Authors: Zhou Jingan , Chen Hong , Fu Houqiang , Fu Kai , Deng Xuguang , Huang Xuanqi , Yang Tsung-Han , Montes Jossue A. , Yang Chen , Qi Xin , Zhang Baoshun , Zhang Xiaodong , Zhao Yuji
Published: December 2019

In this paper, we report the fabrication of low loss beta-phase gallium oxide (β-Ga2O3) optical waveguides and the propagation loss analysis of the waveguides in the ultraviolet (UV) to near infrared (NIR) spectral region. The β-Ga2O3 thin films were grown on sapphire substrates using metal organic chemical vapor deposition and were fabricated into various waveguide structures using nanofabrication processes. A low propagation loss of 3.7 dB/cm was obtained on the β-Ga2O3 waveguide at the wavelength of 810 nm, which is comparable to the state of the art. Combined with theoretical simulations, various loss mechanisms from two-photon absorption, sidewall scattering, top surface scattering, and bulk scattering were discussed for β-Ga2O3 waveguides, and their contributions to the total optical loss were estimated. These results show that β-Ga2O3 is a promising optical material for the fabrication of various integrated photonic devices in the UV–NIR spectra region.
Corrigendum to: Guidelines, training and quality assurance: influence on general practitioner MRI referral quality
Authors: Kara Stephen , Smart Alexandra , Officer Tara , Dassanayake Chan , Clark Phil , Smit Amy , Cavadino Alana
Published: December 2019

ABSTRACT
INTRODUCTIONMagnetic resonance imaging (MRI) is an accurate diagnostic test used mainly in secondary care. Uncertainty exists regarding the ability of general practitioners (GPs) to use direct access high-tech imaging pathways appropriately when managing musculoskeletal injury.
AIMTo evaluate the use of primary care-centric guidelines, training and quality assurance on the appropriateness of GP MRI referrals for patients with selected musculoskeletal injuries.
METHODSThis is an 18-month primary care retrospective study. GPs participated in clinical musculoskeletal training, enabling patient referral for MRI on four body sites. Two reviewers categorised referral appropriateness independently, and reviewer inter-rater agreement between categorisations was measured. MRI results and patient management pathways were described. Associations of scan status and patient management were examined using logistic regression.
RESULTSIn total, 273 GPs from 72 practices attended training sessions to receive MRI referral accreditation. Of these, 150 (55%) GPs requested 550 MRI scans, with 527 (96%) eligible for analysis, resulting in 86% considered appropriate; 79% consistent with guidelines and 7% clinically useful but for conditions outside of guidelines. Inter-rater agreement was 75%. Cohen's weighted kappa statistic was 0.38 (95% CI: 0.28–0.48). MRI referrals consistent with guidelines were more likely to show pathology requiring specialist intervention (reviewer 1: odds ratio=2.64, 95% CI 1.51–4.62; reviewer 2: odds ratio=4.44, 95% CI 2.47–7.99), compared to scan requests graded not consistent.
DISCUSSIONStudy findings indicate GPs use decision support guidance well, and this has resulted in appropriate MRI referrals and higher specialist intervention rates for selected conditions.
Targeting changes in soil porosity through modification of compost size and application rate
Authors: Wallace Dirk , Almond Peter , Carrick Sam , Thomas Steve
Published: December 2019

The global demand to increase food production from underperforming, water and nutrient limited soils is increasing, which has resulted in an increased dependency on water for irrigation. As fresh water is a finite resource, the increase in irrigation use has resulted in competition between water used for municipal purposes and that used for food and fibre production for an increasing global population. An opportunity exists to improve the efficiency of both urban and agricultural systems by taking green waste compost generated in urban centres and incorporating it into agricultural soils with poor water retention, thereby increasing the ability of these soils to efficiently retain irrigation water for plant use and also to capture a greater volume of water from rainfall. Addition of amendments to soil changes the pore space. The magnitude and cause for this change depends on amendment type, application rate, soil type and climatic conditions. The aim of this research was to determine if the incorporation of municipal compost (MC) can increase the quantity (total volume) and concentration (total volume per unit volume) of soil pores that hold readily available water (defined as macro-mesopores of 30–3 μm diameter) and plant available water (defined as mesopores of 30–0.3 μm diameter). We hypothesised that increases in total porosity would be positively correlated with MC application rate and increases in water holding porosity (macro-mesoporosity and mesoporosity) would be positively correlated with decreasing MC particle size due to the creation of inter-particle pore spaces < 30 μm in diameter. The MC was screened to three different maximum particle sizes – MC4 (<4 mm), MC2 (<2 mm) and MC0.25 (<0.25 mm) – and incorporated into repacked soil cores at five different rates: 0, 5, 25, 50 and 80% wt/wt. Incorporation of MC0.25 increased the concentration and quantity of macro-mesopores and mesopores at significantly lower application rates than MC4 and MC2. The finding that modification of MC particle size can produce targeted changes in inter-particle porosity suggests that this practice has potential to remediate hydraulic limitations of soils.
Rebracketing (Gliederungsverschiebung) and the Early Merge Principle
Authors: Weiß Helmut
Published: December 2019

The concept ofGliederungsverschiebung(rebracketing) was introduced by the Neogrammarians and it is probably the first explanation of syntactic change proper. Originally, it was conceived of to explain the emergence of the complementizerdass“that”, which was held to go back to a demonstrative pronoun that refers cataphorically to a following main clause and which was eventually reanalyzed as introducing the second clause. This paper presents several examples of rebracketing (mainly from various stages of German) and argues that rebracketing is only possible if the clause whose boundary is shifted is embedded under and selected by a lexical head that is eventually reanalyzed as a complementizer. This condition on rebracketing follows from the fact that otherwise, the respective clause would be a phase and no longer accessible for operations from outside (thus excluding rebracketing). Additionally, the paper argues that rebracketing is economy-driven in that it minimizes the structure and it is motivated by the Principle of Early Merge that applies whenever no further movement follows.
Quantum Interpretation of Light Normalization at the Coupling Region Single Mode Fiber Coupling
Authors: Irawan Dedi , Saktioto
Published: December 2019

This paper describes light normalization phenomenon as a quantum interpretation at the coupling region optical fiber coupler. Two single mode fibers (SMF) were succefully fabricated together based on fusion method at heating temperature of 1350°C and stopped automatically when the pre-set coupling ratio of 50% and 50% obtained. During fusion process, 1 mW laser diode was inserted to the one of the two input ports, and it was gradually transferred to the second fiber as function of the coupling coefficient. The properties of light intensity in term of electromagnetic wave also was determined based on quantum mechanics theory by utilizing Bassel and Hankel’s functions. The results show that the composite fiber has higher normalization propagation constant than other fiber for wavelength below 1320 nm. It found that to get lossless fiber coupler the wavelength operation should be below than 1320 nm so that few powers at cores transferred and propagated at the cladding.
The Effects of Different Activation Agents on the Physical and Electrochemical Properties of Carbon Electrodes Produced from Banana Stem Fiber
Authors: Taer E , Yusra D A , Apriwandi  , Awitdrus  , Taslim R , Agustino
Published: December 2019

This study focuses on the effects of chemical activation materials on the physical and electrochemical properties of carbon electrodes made from banana stem fiber. The carbon electrodes were activated with different activators such as KOH, NaOH and ZnCl2 at a constant concentration of 0.5 M. Also, the electrodes were carbonized at a temperature of 550°C followed by a physical activation process using CO2 at 900°C for 2.5 hour, after which the density, surface morphology, element contents, degree of crystallinity and surface area of carbon electrodes were analyzed. In general, the activator used determines both the physical and electrochemical properties of the electrodes. Also, activating materials have the capacity to improve the physical properties of the samples as well as increase its specific capacitance. According to this research, AC-ZnCl2 shows better physical and electrochemical properties having a specific capacitance as high as 130 F g−1.
Optimation of Capacitor Bank Placement in Electric Network Using Genetic Algorithm
Authors: Arlenny  , Zondra Elvira , Zulfahri
Published: December 2019

Minimizing losses in electric network should be considered the placing a shunt capacitor, the voltage level on each bus, the size and number of shunt capacitors to be used, and the supply of maximum and minimum of generator power. This paper is conducted the determination of location and size of shunt capacitor to be allocated in electric power transmission networks. The simulation using Genetic Algorithms (GA) method was applied to solve the problem of reactive power compensation optimation. To find out amount of compensation for voltage drop and power losses that occur in the system, a load flow analysis was performed using the Newton-Raphson method. The result of capacitor placement and capacitor capacity were shown the highest voltage conditions on bus 4 of 1.050 Mvar and the lowest on bus 24 of 9.69 Mvar. The optimization system was revealed the total losses system of 12.793 MW with a total generation cost of 15447.44 $/h for the capacitor reduction size of 18.8 Mvar. Therefore, the system can save 6.2 Mvar’s capacitors.
Smart Monitoring Temperature and Humidity of the Room Server Using Raspberry Pi and Whatsapp Notifications
Authors: Kurniawan Dwi Ely , Iqbal Mohd , Friadi John , Borman Rohmat Indra , Rinaldi Rio
Published: December 2019

The server room is a room that stores data, there is company information (Data Center). Hot server room conditions can cause performance on the device and network to decrease. Therefore an admin must keep the server space stable so that the server and network performance is maintained. The temperature monitoring system can be used to monitor temperature and humidity in the server room. In addition, it provides a response to reduce the temperature if there is a temperature increase in the server room. This study uses the Internet of Thing (IoT), which is a device used by the Raspberry Pi and Wemos DHT Shield wireless sensor as a device that is able to read the temperature and humidity conditions of the room. Temperature and humidity log data is stored in the MySQL database, then displayed in a chart diagram in real time. IoT response based on predetermined temperature standards by giving notifications to users via Whatsapp Application on mobile devices.
Analysis of performance comparison between Software-Based iSCSI SAN and Hardware-Based iSCSI SAN
Authors: Kurniawan Dwi Ely , Ahmad Imam , Ridho Muhammat Rasid , Hidayat Fendi , Anggra Js Ahmad
Published: December 2019

Nowadays computer data grows rapidly and make a lot of institutions and companies looking for storage solutions that are safe, reliable and trustworthy. One of the solutions is to implement a Storage Area Network (SAN). In this study, the authors chose the iSCSI protocol as an object for analyzing the performance of the SAN server based on software and hardware. The RAID type used are RAID 5 and RAID 10, while the parameters used are Input Output per Second (IOPS), throughput and average latency with workloads 4 KB, 8 KB, and 256 KB. The tests performed on the network running Link Aggregation (LAG) or network without LAG. From the test results, it is seen that a SAN network running LAG have increased throughput by 89.57 MBps. The best IOPS performance was achieved by Software-Based iSCSI SAN with a value of 26729.48 IOPS. The best throughput performance is achieved by Hardware-Based iSCSI SAN with a value of 118.55MBps. The best latency performance achieved by Software-Based iSCSI SAN with a value of 2.01ms.
Coating Hydroxyapatite on 316L Stainless Steel Using Electroforesis Deposition Method
Authors: Fadli Ahmad , Komalasari  , Indriyani Ines
Published: December 2019

Stainless steel 316L is a metal which used as bone plate, however this metal has low biocompatibility in a human body. For increasing their biocompatibility, the stainless steel 316L need to be coated with hydroxyapatite (HA). The purpose of this research is to study the effect of applied voltage and deposition time on the properties of HA coated 316L stainless steel. Stainless steel 316L was cut into 20×20×1 mm3dimension then HA solution was prepared in ethanol solution used magnetic stirrer for 2 hours and 200 rpm. The HA powder was deposited by electrophoretic deposition (EPD) using carbon as anode and stainless steel 316L as cathode. Powder was coated on stainless steel substrate at 40, 50 and 60 volt and deposition time 10, 20, and 30 minutes. Thickness of HA layer on substrate increased, as the time deposition increased with resultof 35 μm, 50 μm and 60 μm at deposition 50 volt and deposition time of 10, 20 and 30 minutes. Thickness HA coatings can decrease the corrosion of stainless steel, in deposition time 10, 20, and 30 minutes is 0.91, 0.704, and 0.56 mpy. at applied voltage 50 volt and deposition time 30 minutes was obtained suitable for bone plate.
The Development of MOOC Media to Increase Recall Memory Skill on Physics at Vocational High School
Authors: Busri Eldwita , Zulirfan  , Fakhruddin
Published: December 2019

The learning media is one of facilities in order to achieve the purpose of physics subject. The aim of this study is to develop online learning media web-based which known as MOOC (Masive Open Online Coursuse). This Physics MOOC consists of students and teacher page (admin), on the students page consists of three main menu; module, quiz and score, while the teacher page consists of 5 main menu; class, students data, module, quiz and students score. Physics MOOC provides online learning that can be accessed whenever and wherever, using either android or PC so that it facilitates students and teacher do learning process without face to face. The result of this study is determined by the implementation of physics online learning web-based without face to face between teacher and students.
Analysis of Attenuation Compensation Using Erbium Doped Fiber Amplifiers on Wavelength Division Multiplexing Networks as Optical Amplifiers in Communication Systems
Authors: Saktioto  , Fitriadhani S , Syahputra R F , Okfalisa  , Syamsudhuha
Published: December 2019

Communication technology is currently very rapidly growing that causes the need for data flow speed increase significantly. These needs could be met through the technology of a fiber optic. The addition of use wavelength division multiplexing (WDM) networks can increase the bandwidth value because this network system can enter several wavelengths in a block diagram that is a multiplexer. This paper will discuss concerning a WDM that uses optical amplifier EDFA to strengthen a transmitted signal with input signal is sent two channel in one axis a fiber optic. Approach was used in the study simulations with three types of variation. The results of the simulation showed the variations of this type of circuit, the circuit is a form of consumption preline most excellent attenuation coefficient has 0.593 dBm/km, the variation of the value of the bandwidth on the value of 200 GHz is the value that best has a attenuation coefficient dBm 0.026/km and variations of long fiber optics at a distance 1 km that is the distance transmission of maximum.
Numerical Analysis of Stress Causing Fracture Failure in the Gear Transmission System Applied on an Agricultural Machinery Equipment
Authors: Husaini  , Dawud D M
Published: December 2019

In general, failures often occur in gear transmission systems, even this case also occurs in an agricultural machinery equipment for example in a hand tractor. This study aimed to determine the cause of the spur gear fracture through numerical studies. The fracture surface was observed using a scanning electron microscope (SEM) in order to identify crack initiation. The results of the chemical composition test indicated that the material used was according to the AISI 8620 standard. It is necessary to create a finite element analysis (FEA) modeling. The stress, strain and stress intensity factor was next analysed near the crack tip using the FEA. The results of the FEA pointed out that the value of the maximum stress intensity factor KI
occurs in the center of the tooth which experiences an initial crack due to friction. The KI
value obtained from the FEA indicates that the value is higher than the fracture toughness KIC. Finally, crack propagation occurs in the teeth of the spur gear that causes the tractor to stop working.
Identification of Pure and Adulterated Honey Using Two Spectroscopic Methods
Authors: Shiddiq Minarni , Zulkarnain  , Asyana Vepy , Aliyah Himmatul
Published: December 2019

Honey is a natural sweet substance which is often mixed with other liquids for health purposes or as a sugar substitute in variety of food. Due to high commercial profit, many fraudulent acts have been around to add other substances to pure honeys. This study used two spectroscopic methods which are the laser induced fluorescence (LIF) and Fourier Transform Infrared (FTIR) spectroscopy to differentiate pure and corn syrup adulterated honeys based on sugar content. LIF used a 405 nm diode laser as the excitation laser. Samples of 27 were prepared for this study. They composed of 15 pure honey and 2 non honeys, and 10 adulterated honeys which we coded from A to Q.. Non honey samples were pure date syrup and corn syrup which coded as K and L. The sugar contents were measured manually using a brix refractometer which resulted the honey sugar contents range of 69.5 % to 78 %. The peak wavelengths observed range from There is R2 = 0.80 correlation between peak wavelength of fluorescence colours to sugar contents. The results showed that the peak wavelengths range from 490.9 nm to 641.3 nm. LIF was able to differentiate between the pure honeys than the adulterated or mixed ingredient honeys except for sample C. The differences of FTIR spectrums were shown by honey samples which was not given corn syrup adulteration, where the difference begins to be seen clearly at the wave number range 1150 cm−1 to 650 cm−1.
Analysis of matK, rbcL and trnL-trnF Intergenic Spacer Sequences on Durik-Durik (Syzygium sp)
Authors: Roslim Dewi Indriyani
Published: December 2019

Syzygium sp. with the local name of durik-durik, that grows in Riau Province, Indonesia, is one of many adapted plants to flooding stress in floodplain ecosystems, and plays a role for survival of the ecosystems. This study reports analysis of three DNA barcodes, i.e. matK, rbcL and trnL-trnF intergenic spacer on this plant. The fresh leaves of this plant were picked up from floodplain ecosystem in Pelalawan, Riau Province for DNA extraction requiring. In this study had been obtained DNA sequences of matK, rbcL and trnL-trnF intergenic spacer with the size of 686 bp, 641 bp and 828 bp, respectively. The BLASTn analysis based on those sequences showed that none of the accessions of the Syzygium genus were 100% similar to Syzygium sp. The phylogenetic tree showed that Syzygium sp. formed one group with the same species of Syzygium and separated from other genera in Myrtaceae family. These results confirmed that durik-durik was a member Syzygium. Those sequences had been deposited in GenBank and could be used for molecular identification of this plant.
Identification of a Potential IAA-Producing Fungus Isolated From Alpinia Sp. Rhizome in Hutan Sibayak, North Sumatera
Authors: Hartanto Adrian , Lutfia Anisa , Munir Erman , Yurnaliza
Published: December 2019

Medicinal plant from members of Zingiberaceae have been used as traditional remedies by marginal communities. To date, information and potential of these endophytes, especially endophytic fungi is still limited to certain taxa and properties. The present study investigates one of plant growth promoting properties possessed by endophytic fungi, which is the ability to produce extracellular Indole-3-acetic acid (IAA). Rhizome of Alpinia sp. sampled from Hutan Sibayak, North Sumatera was used as source of isolation of endophytic fungi. The endophytic fungal isolates were grown in Czapek-dox broth supplemented with 0.1% (w/v) L-tryptophan for 7 days to induce secretion of extracellular IAA. IAA concentration was measured colorimetrically using Salkowsky’s solution by comparing absorbance (A530) of standard pure IAA with culture filtrates from each isolates. The study obtained 5 endophytic fungal isolates from Alpinia sp. rhizome differentiated morphologically. The highest IAA content in culture filtrate (42.91±1.41 μg.mL−1) was produced by isolate Al04SU followed with Al02SU, Al05SU and Al01SU with IAA concentration of 26.25, 19.55 and 17.26 μg.mL−1, respectively. Molecular identification of isolate Al04 based on ITS-DNA similarity showed that isolate was closely related to Aspergillus flavus and confirmed through phylogenetic tree construction. The presence of IAA-producing endophytic fungi from Alpinia indicates that medicinal plant may harbor bioprospective strains which could be used in crop improvement with further and deeper investigation.
The Secondary Metabolite Diversity Analysis of Three Mangifera Foetida L. Varieties Based on Liquid Chromatography-Mass Spectrometry (LC-MS)
Authors: Fitmawati  , Khairunnisa  , Resida Esi , Emrizal  , Mustika Roza Rodesia
Published: December 2019

Mangifera foetidaL. (Macang) is the type of mangoes that contains the highest levels of mangiferin which has activity of antioxidant, analgesic, anti-drip, anti-inflammatory, antitumor, immunomodulatory and anti-HIV. The potential of Macang as a drug needs to be assessed through phytochemical studies to obtain information on the diversity of Macang secondary metabolite content that is potential to be developed. The purpose of this study was to reveal the diversity of total secondary metabolite compounds contained in Macang with three varieties (Limus, Batu and Manis) using LC-MS analysis. Sampling was carried out use survey method at Remban and Lesung Batu, Kecamatan Rawas Ulu, Kabupaten Musi Rawas Utara, South Sumatra Province. The chromatogram was analyzed using the MassLynx program to obtain the compounds contained in the sample. Names determination of compounds based on Chemspider database and compound classes based on PubChem. The number of metabolite compounds that become characteristic of three Macang varieties in this study was 667 compounds. Limus has a specific compound of 191 compounds, Batu of 162 compounds, and Manis has a specific compound of 202 compounds. The metabolites found in this study are expected to be useful in phytopharmaca and support Macang conservation efforts that rarely found.
Effect of 6-Benzylaminopurine and Honey for in Vitro Shoot Initiation of Mangosteen Seed Explant From Riau, Indonesia
Authors: Isda Mayta Novaliza , Amin Nur Aisyah , Fatonah Siti
Published: December 2019

Mangosteen (Garcinia mangostana L.) is a tropical plant that has export value because it has a rich of antioxidant xanthone that can be used for medicine as an anti-cancer agent. Mangosteen (Garcinia mangostana L.) from Riau, Indonesia has many superiorities such as grow in the marshes and tolerant to acid soil (peat soil). One of the alternative methods to produce large number and uniform mangosteen seedlings in a short period can be done using in vitro culture technique. The purpose of this research was to determine the optimal concentration of BAP and honey in shoot initiation of mangosteen explant from seed that had been divided into four parts and also to determine the best combination for initiation mangosteen shoots using in vitro method. This research used a Completely Randomized Design (CRD) with the concentration of BAP (3; 7 mg/l) and honey (3; 6; 9 ml/l) or in combination on MS medium with five replications. The result showed that the highest number of shoots (14.60) formed on MS medium supplement with 7 mg/l BAP + 3 ml/l honey. The combination between 3 mg/l BAP + 3 ml/l honey produced the tallest shoots (5.10 cm) and the highest number of leaves (3.20 leaves) on MS medium supplement with 3 mg/l BAP + 9 ml/l honey. In this study, we have successfully presented the effect of 6-benzyl amino purine and honey for in vitro shoots initiation from mangosteen seed explant (Garcinia mangostana L.) which taken from Riau Indonesia.
Synthesis and Characterization of New Ruthenium-Tungsten Bimetallic Complex Equipped With Anchoring Ligand
Authors: Wardani PK , Anggraini D , Awaluddin A , Kassim MB , Arifin K
Published: December 2019

A new ruthenium-tungsten bimetallic complex equipped carboxylic as anchoring ligand and thiocyanate as bridging ligand has successfully synthesized. Ruthenium complex and tungsten hexacarbonyl are used as starting materials. The synthesis process involves two-step reactions in one-pot with ultraviolet light and monitored by FTIR spectroscopy. The final product fully characterized by UV-Vis, FTIR, 1HNMR, 13CNMR, and LCMS spectroscopies analysis confirms that the product is a bimetallic complex with molecular formula Ru(C12H8N2O4)2-(NCS)2-W(CO)4. Cyclic voltammetry of the complex exhibit one reversible redox couple, two quasi-reversible redox couples and one irreversible redox peak. The complex absorbs light energy in a wider solar spectrum compared to related ruthenium complex. The complex is supposed to be a good dye-sensitizer to improve TiO2 photoelectrode performance in artificial photosynthesis applications.
Cos as Co-Catalyst for Enhancing the Tio2 Photoelectrochemical Water Splitting
Authors: Agustina M , Linggawati A , Arifin K
Published: December 2019

Titanium dioxide is a semiconductor that widely applied because it is environmentally friendly and has good catalytic activity. However, the wide band gap of TiO2 limits its application in photocatalytic activities. Cobalt sulfide (CoS) is extensively used as a photocatode in photoelectochemistry because it has good electrochemical activity, low cost and non-toxic. The formation of p-n junction between TiO2 and CoS can reduce the band gap of the former, and the load transfer of photoelectrochemical activity can be increased. TiO2/CoS is a promising photocatalyst in enhancing photoelectrochemical performance. In this work, a TiO2/CoS thin film was synthesized through hydrothermal method to study the effect of CoS on TiO2 and improve the photoelectrochemical performance. Characterization were performed using X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and UV reflectance. Results showed that as-synthesized TiO2/CoS was a mixed phase of TiO2 (anatase, rutile) and CoS with agglomerate-shaped small particles. The band gap of TiO2 was reduced after CoS was loaded at 2.75 eV. The density of as-synthesized sample was 1.2572 mA at 1 V compared with Ag/AgCl under light irradiation.
Synthesis and Catalytic Activities of Manganese Oxides Prepared by Precipitation Method: Effects of Mixing Modes of Reactants and Calcination Process
Authors: Kurniati S , Asleni  , Linggawati A , Siregar S S , Awaluddin A
Published: December 2019

The two phases of manganese oxides are prepared by two different mixing modes using the same precipitation method from the solutions of KMnO4 dan maltose, resulting in marked different phase structures and catalytic activities. The oxides synthesized by adding dropwise of the maltose solution into KMnO4 solution (method A) resulted in the formation of layer manganese oxide birnessite, which turns into tunnel structured manganese oxide cryptomelane following the calcination at 600°C for 4 hours. The simultaneous addition of KMnO4 solution and maltose solution (method B) also produced birnessite before calcination, but remain unchanged as birnessite phase after calcination with cryptomelane as minor product. The samples without calcination obtained from method A posseses higher surface area and poor crystallinity compared to that with calcination. The catalytic test using Fenton-like Reaction for methylene blue (MB) degradation indicated the tremendeous difference in their catalytic activities for both samples without and with calcination. The birnessite catalysts (without calcination) prepared using method A show the highest activity and are able to degrade 93% methylene blue within 10 minute, much higher than other samples.
pH-Control of Oxidative Degradation of Methylene Blue Over Octahedral Molecular Sieve Cryptomelane-Type Manganese Oxide (OMS-2) and Fe-OMS-2
Authors: Sandra I , Muhdarina  , Anggraini R , Siregar S S , Awaluddin A
Published: December 2019

The octahedral molecular sieve cryptomelane-type manganese oxide (OMS-2) and Fe-doped OMS-2 (1%, 5%, 10%) were successfully synthesized by the redox reaction between KMnO4 and citric acid using the sol-gel method. The sol products were heated at 120°C and followed by calcination at 600°C. The as-synthesized pristine manganese oxide and Fe-OMS-2 were then characterized by XRD to determine their crystallinity and phase structure. The XRD results indicated that both the pristine and Fe-doped manganese oxides produced tunnel cryptomelane-type manganese oxides. No other peaks due to other phases are detected, indicating that Fe ions are well distributed in the framework of cryptomelane. The oxidative activities, either the pristine and Fe-OMS-2, were evaluated for degradation of methylene blue (MB) at pH ranges 2-6 by the addition of HCl solution. The oxidative tests showed that the oxidative degradation of methylene blue greatly increase with a decrease in solution pH and decrease with an increase in concentration Fe species in Fe-OMS-2 compared to pristine cryptomelane.
The Tremendous Influence of Calcination Process on the Phase Structure and Catalytic Activity of Precipitation-Processed MnO2
Authors: Asleni  , Kurniati S , Linggawati A , Siregar S S , Awaluddin A
Published: December 2019

The layer and tunnel manganese oxides are versatile materials and have been proposed for various applications. These materials are prepared by a wide range of methods such as sol-gel, solid-state, precipitation and etc. Here, both manganese oxides of birnessite (layer) and cryptomelane (tunnel) have been successfully synthesized using the precipitation method by the reaction between KMnO4 and glucose with a mole ratio of 3:1. XRD results indicated that the birnessite-type manganese oxide was obtained when the brownish-black precipitate was heated up to 120°C, whereas cryptomelane-type manganese oxide was generated when the as-synthesized sample was further calcined up to 600°C. The birnessite sample displays poor crystalline material with low intensity and broad peak. The heat-treated birnessite up to 600°C leads to the formation much more crystalline tunnel cryptomelane–type mangane oxide. The catalytic activities of the as-synthesized catalysts were tested for the degradation of methylene blue (MB) dye with H2O2 as an oxidant. The birnessite catalyst shows much higher catalytic activity for the degradation of methylene blue compared to the cryptomelane catalyst. The tremendous improved catalytic activity of birnessite catalyst are correlated with its poor crystallinity and higher surface area of as indicated by the BET surface area and the XRD results.
Surface Acidity of Sulfuric Acid Activated Maredan Clay Catalysts with Boehm Titration Method and Pyridine Adsorption-FTIR
Authors: Vifttaria M , Nurhayati  , Anita S
Published: December 2019

The acid or base of the solid surface is a very interesting aspect at the structure of surface and important in the field of ion exchange and heterogeneous catalysts. The use of clay as a heterogeneous catalyst is due to its acidity. In this paper, the acidity of heterogeneous catalysts Maredan clay activated by sulfuric acid was examined by the Boehm titration and adsorption pyridine method. In this study, Maredan clay was activated with several variation concentration of sulfuric acid (0.5, 1, 2 and 3 M) by impregnation method. The mixture was refluxed at 80°C for 3 hours, washed with double deionised water, dried and calcined at 500 °C for 3 hours. The results showed that activation of Maredan clay by sulfuric acid produced the total acid amount of 0.6483 mmol/g catalyst by using Boehm titration method and 1.1137 mmol/g catalyst by using pyridine vapor adsorption method. FTIR analysis of the spectra of pyridine adsorption was seen that the acid site of the Maredan clay catalyst activated by sulfuric acid dominant was Lewis acid site, with wave numbers at 1449.57; 1490.07; 1573.98 and 1616.42 cm−1.
Gram Positive Antibacterial Activity of Ethyl Acetate Extract of Penicillium sp. LBKURCC34’s Growth Media Stimulated by Staphylococcus aureus
Authors: Nurulita Yuana , Yuharmen  , Herdiyanti Citra , Khairullinas  , Nugroho Titania Tjandrawati
Published: December 2019

This study was aimed to evaluate the antimicrobial activity of local isolate of peat swamp soil strain, Penicillium sp. LBKURCC34 on Gram positive pathogen, B. subtilis ATCC11774 and S. epidermidis ATCC12228. The fresh strain of Penicillium sp. LBKURCC34 and Staphylococcus aureus was added into fermentation media and incubated for 14 days. The media extracted with ethyl acetateand evaporated, then the concentrate dissolved in methanol. Antimicrobe test was performed by the disc diffusion method and the resazurin-based turbidometric method toward Gram positive bacterial pathogens (Bacillus subtilis ATCC11774 and Staphylococcus epidermidis ATCC12228). The crude extract could inhibit the growth of these pathogen microorganism. The extract with biotic stimulation has higher activity than the extract without biotic stimulation. It could give 10% higher activity against Bacillus subtilis ATCC11774 compared with positive control, amoxicillin. This fungal strain is potential as antibiotics producer.
Mapping the Distribution and Characterization of Sandstone Reservoir Using Simultaneous Inversion Method in “OA” Field at Northern Bonaparte Basin
Authors: Wiyatno Oki Fimansyah , Rosid M. Syamsu , Purba Humbang
Published: December 2019

The sandstone reservoir in the “OA” Field is situated in the Northern Bonaparte Basin, which is gas-saturated sandstone. Mineral diagenesis is also causing several reservoir zone areas to become tight sand. The inversion method using acoustic impedance (AI) is less sensitive in distinguishing sandstone and clay rock lithology since they have almost the same impedance. Simultaneous Inversion overcomes this problem by simultaneously inversing partial angle data (near, mid, far) to obtain physical parameters besides acoustic impedance which are expected to be more sensitive in distinguishing lithology and predicting the presence of gas fluids such as shear impedance (SI) and density. These three parameters can be derived as Lame (LMR) parameters. Cross plot analysis shows sensitive physical parameters to predict the distribution of lithology and the presence of gas fluid. Density sensitive in distinguishing lithology which is then inverted, obtaining sandstone cutoff values are 2.3-2.5 (g/cc), tight sand with cutoff 2.5-2.625 (g/cc) and clay stones with cutoff 2.625-2.8 (g/cc). The presence of gas fluid is predicted by inversing the parameter Vp/Vs
which has a cutoff of >1.6 and Lambda-rho cutoff of >25 (Gpa)*(g/cc). Analysis of the parameter distribution map shows the distribution of sandstones and the presence of dominant gas fluids in the northern area of the research zone with relatively clean sandstone, compared to relatively more southern regions.
Feasibility Study of Riverbed Filtration Technique at Sungai Kampar Perak by using Numerical Modelling
Authors: Mohamad Faizal T B , Mohd Nordin A , Nor Azizi Y , Zaidi E
Published: December 2019

Population growth will result in the increase of water supply demand. Riverbed filtration or radial collector well technique is one of the options for increasing the water supply. Drainage Package of Visual MODFLOW was used for the riverbed filtration modelling. The modelling aimed to identify the optimum pumping rates withdrawal in order to fulfill Lembaga Air Perak requirement for additional water supply. Installation of radial collector wells in the depth of 10-12 m aquifer thickness at Sungai Kampar Perak would increase the supply of clean water for future water demand. The design of riverbed filtration technique consists of 4 m radius of collector well with depth of 10.54 m and five radials wells with 40 m length across the riverbed. Transient condition of the groundwater flow modelling result showed that the optimum pumping rate can meet the water supply requirements of about 35 MLD (35000 m3/day).
Identification of Saline Water and Fluid Flow in Tanjung Priok and Koja North Jakarta Using Geoelectric Method
Authors: Rosid M S , Kusuma F B , Ayu G P
Published: December 2019

To date the cause of saline water in Jakarta area is still debated. One opinion says that salty ground water is caused by sea water intrusion. Other opinions stated that the salty water appears from connate water. The objective of this study is determining the causes of saline water in North Jakarta, especially in Tanjung Priok and Koja. The method used to describe the subsurface fluid flow and resistivity spread is geoelectric method. The method consists of SP (self potential) for fluid flow and resistivity for distribution of subsurface saline water. The data is processed using RES2DINV software and interpreted with processed SP to produce a cross-section map. The results of these two methods are also supported by geological data and wells data samples as well as gravity data in the form of FHD (first horizontal derivative). The results of the resistivity indicate the presence of saline water at a depth of 5-10 meters which is a shallow aquifer. The saline water in this study area most likely caused by the sea intrusion as the SP results show that the subsurface groundwater flows from North to South.
The First Study of 3-D Seismic Velocities Tomography Inversion to Delineate Reservoir Steam Zone at “FR” Geothermal Field West Java
Authors: Farhan  , Syamsu Rosid M. , Riziq Maulana M. , Iskandar Chevy
Published: December 2019

Understanding reservoir conditions is one of the important aspects in fluid production monitoring activities in geothermal systems. The objective of this study to delineate the reservoir element especially the steam phase. It is the first study to requires mapping the existence and geometry of steam phase as an initial step to monitor reservoir conditions at “FR” Geothermal Field using the tomography travel time method. This study used seismogram data measured for 95 days and recorded by 11 seismometers. Arrivals time picking results get 213 microearthquake events with a minimum recorded by 3 recording seismometers. Hypocenter relocation is done by two methods in combination. The first use Joint Hypocenter Determination (JHD) and second use Double Difference relocation method. Then the travel time tomography inversion is using simulps12 software. The results of the hypocenter relocation distribution show one cluster around the main production well those are PPX well may be related to weak zones and reveal majority structure with NW-SE orientation. While in terms of hypocenter depth distributed clusters around the trajectory of production wells B and C from elevations +1 to 0 Km. The tomogram results show that the delineate steam zone at an elevation of +1 to 0 Km with strongly low perturbation VP
, low VS
and low VP
/VS
with arround 1.6 to 1.7 value. Integration with MT data show the steam zone has located at reservoir boundary zone with resistivity value of 30 to 60 Ohm meter. Integration with PPX temperature profiling shows the steam zone has convection heat transfers.
Resistivity and Physical characteristic of Meranti’s Peat
Authors: Yusa M , Sutikno S , Lita D , Ari S , Evelyn  , Fadli D , Dian P
Published: December 2019

Peat physical properties (e.g. unit weight, water content, ash and fibre content) are different from mineral soil due to it high water and organic content. Traditional method requires laboratory test which is time consuming and costly. This study attempted to estimate peat physical properties based on its resistivity value. Peat samples were obtained from several locations and various depth using peat sampler in Lukun village at Meranti Distric, Riau Province. The resistivity value measured in the field using 4 pin soil resistance meter along with the determination of moist weight and unit weight. Laboratory tests were conducted on the sample. Statistical analysis was then performed to check whether there is correlation between field resistivity value and peat physical parameters. The result revealed that water content and dry unit weight are correlated to some degree with resistivity value but not for other parameters i.e. wet unnit weight, specific gravity and ash content.
Implementation of Environmental Education Based Local Potential to Increase Environmental Knowledge Student
Authors: Wulandari Sri , Suwondo  , Haryanto Rudy
Published: December 2019

The challenge of complexity environmental problems requires intensive efforts by environmental education. However, students’ environmental knowledge about of the surrounding local potential is low. It is necessary to integrated implementation of environmental education based local potentials to enhance students’ environmental knowledge. This research was conducted on students at Teaching and Education Faculty, Universitas Riau in August-December 2018. Implementation of environmental education based local potentials was carried out in learning with integrating contents of environmental education curriculum is the concept of ecosystems, environmental problems and environmental management based local wisdom, with data and field facts owned by Riau Province. Implementation is carried out in control and experimental classes, selected based on the homogeneity and normality values of the students’ environmental knowledge. Parameters analyzed were the learning feasibility value by observer and student’s environmental knowledge. Results showed that implementation of environmental education based local potential was very good (0.96-1.00). Implementation learning can increased students’ environmental knowledge by 0.60 (moderate), better than control class by 0.21 (low). So that implmentation of environmental education based local potential can be used as an alternative effort to improve students’ environmental knowledge.
Development of Sound Wave Experimentation Tools Which Influenced by Relative Humidity Using Audacity
Authors: Mariyo Hadis , Islami Nur , Azizahwati
Published: December 2019

The development of experimental tools is important for teachers to assist in the learning process of physics. The purpose research is to develop a sound wave experiment tool that is influenced by relative humidity. The experiment tool was made using a closed and open end PVC tube with a length of 142 cm. Relative humidity obtained is boiling water vapor. Water vapor is entered the PVC tube and the relative humidity level is measured in the tube using a hygrometer. The experiment tool is equipped with audacity software to detect and display sound waves which enter PVC tube. The experimental results are viewed through a graph of sound velocity against relative humidity levels in the tube. When the temperature is 29°C the relative humidity value is 86% with a sound speed of 412 ms−1 and measurement error of 2.01%. The conclusion is the speed of sound increases linearly with increasing relative humidity.