bluuebunny/crossref_metadata_2025 huggingface dataset:
On improving the accuracy of self-calibrated stereo digital image correlation system
Authors: Iniyan Thiruselvam N , Subramanian S J
Published: August 2020

Stereo digital image correlation (stereo DIC), a full-field deformation measurement technique, is increasingly being used to resolve strains at µm-length scale by using microscope-like imaging systems. Self calibration of these imaging systems is more cost-effective and convenient than the conventional target-based calibration. Though the use of self-calibrated stereo DIC systems has already been reported, less attention has been paid to improving the accuracy of these systems. In the present work, we improve the accuracy of a self-calibrated stereo DIC system, which is composed of two full-frame DSLR cameras coupled to macro lenses and is used for testing ASTM E8M sub-sized flat dog-bone specimens. First, we collect the images of two of the speckled test specimens that subtend an angle of 12° between them using an f/25 aperture. Our image-collection strategy leads to a convergent imaging configuration with viewpoints that range from −45° to 45° across two perpendicular directions. Next, we process the collected images in a commercial photogrammetric calibration software by using more than nine image points for computing each object point. We validate our findings on a rigid-body motion test and a uniaxial tensile experiment, and we observe an excellent agreement between the stereo-DIC measurements and the ground truth. Using our findings, the reprojection error of self calibration is improved from 0.3 pixel to 0.1 pixel. The error in the stereo-DIC strain measurements is always less than 3.4% with the improvements made to self calibration, whereas it is as large as 7.6% without them.
Copper nanoparticle decorated non-woven polypropylene fabrics with durable superhydrophobicity and conductivity
Authors: Zhu Shimeng , Kang Zhixin , Wang Fen , Long Yan
Published: August 2020

In this study, a facile method was prepared to fabricate highly flexible, conductive and superhydrophobic polymer fabrics. Copper nanoparticles (CuNPs) were decorated on polypropylene fabrics using a simple spraying method and superhydrophobicity was obtained after vacuum drying for 4 h without any surface modifier. Accumulation of CuNPs constituted coral-like rough micro-nano structures, forming a stable Cassie model and endowing the surface with dense charge transport pathways, thus resulting in excellent superhydrophobicity (water contact angle ∼159°, sliding angle ∼2.3°) and conductivity (sheet resistance ∼0.92 Ω sq−1). The fabrics displayed superior waterproof and self-cleaning properties, as well as great sustainability in the water. Additionally, the superhydrophobicity and conductivity can be almost maintained after heat treatment, wear testing, water droplet impinging, weak alkali/acid treatment and repeated bending-kneading tests. These superhydrophobic and conductive fabrics that are free from moisture and pollution can be a reliable candidate to solve the water-penetration issue in the rapid development of flexible electronics.
Conversion of volatile organic compounds in a twin surface dielectric barrier discharge
Authors: Schücke Lars , Gembus Jan-Luca , Peters Niklas , Kogelheide Friederike , Nguyen-Smith Ryan T , Gibson Andrew R , Schulze Julian , Muhler Martin , Awakowicz Peter
Published: August 2020

A voltage and power controlled surface dielectric barrier discharge for the removal of volatile organic compounds (VOCs) from gas streams is studied by means of current–voltage measurements, flame ionization detectors, and gas chromatography–mass spectrometry (GC–MS). The discharge is generated in a defined synthetic air gas stream at atmospheric pressure by application of a damped sinusoidal voltage waveform resulting from a resonant circuit. Multiple organic compounds, namely n-butane, butanol, isobutanol, ethyl acetate, diethyl ether, and butoxyethanol, are tested at concentrations of 50, 100, 200, and 400 ppm (parts per million), as well as peak-to-peak voltages of 8 to 13 kVpp and pulse repetition frequencies of 250 to 4000 Hz. The dissipated power within the system is calculated utilizing the measured voltage and current waveforms. The conversion and absolute degradation of the VOCs are determined by flame ionization detectors. An increasing concentration of VOCs is found to increase the dissipated power marginally, suggesting a higher conductivity and higher electron densities in the plasma. Of the applied VOCs, n-butane is found to be the most resistant to the plasma treatment, while higher concentrations consistently result in a lower conversion and a higher absolute degradation across all tested compounds. Corresponding amounts of converted molecules per expended joule are given as a comparable parameter by weighting the absolute degradation with the dissipated power. Finally, specific reaction products are determined by online GC–MS, further confirming carbon dioxide (CO2) as a major reaction product, alongside a variety of less prevalent side products, depending on the structure of the original compound. The findings of this study are intended to promote the development of energy efficient processes for the purification of gas streams in both, industry and consumer market. Potential applications of the presented technique could be found in car paint shops, chemical plants, hospital ventilation systems, or air purifiers for living space.
Corrigendum: Quantum teleportation of thermofields (2019 Phys. Scr. 94 095102)
Authors: Prudêncio Thiago , Filho T M Rocha , Santana A E
Published: August 2020

There was a misprint in the title of the paper: Quantum teleporation of thermofields (2019 Phys. Scr.
94, 095 102). It should be read Quantum teleportation of thermofields. The word teleportation is correct all along the manuscript, but it is misprinted in the title even after the proofread of the paper, by the absence of a t. This lack of attention can be attributed exclusively to the main author of the paper.
Cosmic acceleration caused by the extra-dimensional evolution in a generalized Randall-Sundrum model *
Authors: Kang Guang-Zhen , Zhang De-Sheng , Shi Chao , Du Long , Shan Dan , Zong Hong-Shi
Published: August 2020

We investigate an (n+1)-dimensional generalized Randall-Sundrum model with an anisotropic metric which has three different scale factors. One obtains a positive effective cosmological constant

(in Planck units), which only needs a solution

without fine tuning. Both the visible and hidden brane tensions are positive, which renders the two branes stable. Then, we find that the Hubble parameter is close to a constant in a large region near its minimum, thus causing the acceleration of the universe. Meanwhile, the scale of extra dimensions is smaller than the observed scale but greater than the Planck length. This may suggest that the observed present acceleration of the universe is caused by the extra-dimensional evolution.
Cross-sections for

, and

reactions on molybdenum isotopes in the neutron energy range of 13 to 15 MeV *
Authors: Luo Junhua , Jiang Li
Published: August 2020

Given the insufficient cross-sectional data regarding the 14-MeV-neutron experiment of molybdenum, the vital fusion reactor structural material, and the significant heterogeneities among the reported values, this study examined the (n,2n), (n,α), (n,p), (n,d), and (n,t) reaction cross sections in molybdenum isotopes based on the neutrons produced via a T(d,n)4He reaction carried out in the Pd-300 Neutron Generator at the China Academy of Engineering Physics (CAEP). A high-resolution gamma-ray spectrometer, which was equipped with a coaxial high-purity germanium detector, was used to measure the product nuclear gamma activities. In addition, 27Al(n,α)24Na and 93Nb(n,2n)92mNb reactions were utilized as the neutron fluence standards. The experimental 92Mo(n,2n)91Mo, 94Mo(n,2n)93mMo, 100Mo(n,2n)99Mo, 98Mo(n,α)95Zr, 100Mo(n,α)97Zr, 92Mo(n,p)92mNb, 96Mo(n,p)96Nb, 97Mo(n,p)97Nb, 98Mo(n,p)98mNb, 92Mo(n,d)91mNb, and 92Mo(n,t)90Nb reaction cross sections were acquired within the 13–15 MeV neutron energy range. Thereafter, we compared and analyzed these obtained cross sections based on the existing IAEA-EXFOR database-derived experimental data, together with evaluation results corresponding to ENDF/B-VIII.0, JEFF-3.3, BROND-3.1, and CENDL-3.1 and the theoretical outcomes acquired through TALYS-1.95 and EMPIRE-3.2.3 (nuclear-reaction modeling tools).
Yield ratio of hypertriton to light nuclei in heavy-ion collisions from

= 4.9 GeV to 2.76 TeV *
Authors: Shao Tian-Hao , Chen Jin-Hui , Ko Che Ming , Sun Kai-Jia , Xu Zhang-Bu
Published: August 2020

We argue that the difference in the yield ratio

measured in Au+Au collisions at

= 200 GeV and in Pb-Pb collisions at

= 2.76 TeV is mainly owing to the different treatment of the weak decay contribution to the proton yield in the Au+Au collisions at

= 200 GeV. We then use the coalescence model to extract from measured

the information about the

and nucleon density fluctuations at the kinetic freeze-out of heavy-ion collisions. We also show, using available experimental data, that the yield ratio

is a more promising observable than

for probing the local baryon-strangeness correlation in the produced medium.
The effect of Fe3O4concentration to photocatalytic activity of Fe3O4@TiO2-PVP core-shell nanocomposite
Authors: Sunaryono S , Fitriana D R , Novita L R , Hidayat M F , Hartatiek H , Mufti N , Taufiq A
Published: August 2020

A study on the preparation of Congo red textile dyes using nanocatalysts, Fe3O4@TiO2material, and Polyvinyl Pyrrolidone (PVP) has been successfully carried out. The preparation of these dyes is intended as a controller of the shape and size of particles and as a superior adhesive in solution. Fe3O4@TiO2core-shell (FTP) nanocomposite was carried out by coprecipitation method. The Fe3O4nanoparticles were designed as cores that were synthesized from Cilacap iron sand, while TiO2nanoparticles were selected as a shell through the synthesis of Titanium (III) chloride. Fe3O4@TiO2core-shell nanocomposite is characterized using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR), and UV-Visible Spectroscopic (UV-Vis). Through XRD data analysis, the crystalline nano-phase composite of Fe3O4@TiO2core-shell did not experience significant changes with the addition of Fe3O4concentration. The contribution of the addition of Fe3O4concentration can be observed in changes in sample grain size. The higher the concentration of Fe3O4is, the smaller the grain size of the samples produced, ranging between 6-9 nm and can increase the percentage of degradation of Congo red dyes. In addition, optimum degradation in UV-Vis characterization occurred in FTP 0.5 samples that reached 78.20% at minute 100. The photodegradation effect that occurs in Congo red dyes is caused by photocatalytic mechanisms.
Influence of electrolyte concentration on static and dynamic Lead-Acid battery
Authors: Ghufron M , Istiroyah  , Perwita C A , Masruroh  , Khairati N , Ramadhan F R , Setiawan Y E , Pranata K B
Published: August 2020

Electrolyte concentration is one of the important parameters on Lead-Acid Battery (LAB) outcome. Lead-acid battery has been made with static and dynamic electrolyte treatment where 4 variations of electrolyte concentration (20%, 30%, 40% and 50%) and 1A current applied in the system during charging-discharging test to analyze the relationship of the electrolyte concentration to the battery characteristic and compare static and dynamic lead-acid battery performance. The experiment result that for dynamic lead acid battery, the capacity increases along with the higher concentration from 20% to 40% but decrease at 50% compare to 40% for 3 first cycle charge-discharge test when the static lead-acid battery unwork at concentration 20% and show the increases capacity along with increases concentration. In capacity and efficiency point of view, dynamic lead-acid show better performance compare to static lead-acid battery.
The study of sweep frequency response analysis for inspecting the performance of transformer
Authors: Habibi M A , Zain A A , Sudarto F A P , Kusumawardana A , Wibawanto S , Gumilar L , Wicaksono H
Published: August 2020

Transformer had been widely used for supplying electric power to many motors, such as electric pump, fans, or conveyors. The motor voltage may vary that is depending on its power and speed between one to another motor. The load needs the transformer which generate the proper voltage. Unfortunately, the working performance of transformer is slowly decreasing because of its daily operation. The repetition of the transformer technical assessment by observing the transformer performance is needed. This study provides the periodical inspection of high-power transformer in maintenance and outage condition in the one of utility sites in Indonesia. The checking activity maintenance the eligible performance of the user device. The measurement of Sweep Frequency Response Analysis (SFRA) in the 5th unit had been inspected once in every six years. The measured result was obtained in 2007 and 2013. SFRA test diagnoses the characteristics of transformer winding and core by injecting low voltage at a certain frequency. If SFRA diagnoses the winding fault, then the transformer should be replaced or should get a major maintenance. The result of SFRA measurement provides the transformer winding and core still in a good condition because the shrinkage does not exceed 20% of its standard percentage. Therefore, the 500 kV power transformer, located in PT. YTL East Java, does not have to get serious maintenance.
Radio Frequency-based Smart Control for Lighting in Public Service
Authors: Rifai M , Arfianto A Z , Muzazanah A T
Published: August 2020

In the context of energy efficiency, the control function of electrical equipment is an essential part of saving electricity consumption. That proven by several previous studies about the control of electrical equipment that has been successful for efficiency. In this study, electrical equipment will be controlled in public service buildings, using radio frequency (RF) and the internet. The realisation of this research is to make a radio frequency prototype and an internet-based light control device. For the buildings whose location is difficult to reach by the internet, light control uses radiofrequency. While for buildings that are affordable by internet access, using the internet to control the light. In this study, the microcontroller used is ESP 8266 MCU Node and TCM 3105 FSK IC Modem for connection to the internet. Device performance in running controls measured by the delay. Delay is the time difference between the command input time and the time the device has run the command. The average delay is at an average distance of 1513 ms at a distance of 1 m, 2844 ms at a distance of 10 m, 4674 ms at a distance of 100 m, 4060 ms at a distance of 150 m and 3151 ms at a distance of 300 m. The delay value decreases because, at distances of 100, 150, and 300 connections are lost. Under these conditions, the delay value is considered empty (0) so that the average decreases. The farther the distance, the higher the percentage of unconnected, this can be seen at distances of 100, 150, and 300 m.
Morphology and structure of bacterial cellulose film after ionic liquid treatment
Authors: Suryanto H , Sutrisno T A , Yanuhar U , Wulandari R
Published: August 2020

Chemical treatment like ionic liquid is known as a green solvent had developed to improve the compatibility of bacterial cellulose in many composite applications. This study aimed to know the influence of treatment using the ionic liquid on the morphology and structure of bacterial cellulose film (BCF). The methods used a BCF made of pineapples peels waste. Pellicle, as fermentation product as long as 14 days, washed by distilled water then immersed to an ionic liquid solution such as 1-Butyl-3-methylimidazolium chloride (BmimCl) for 2 h with concentrations of 0%, 2.5%, 5.0%, and 7.5%. Treated BC pellicle was dried in an oven for 6 h for obtaining bacterial cellulose film (BCF) then observed by XRD and SEM. The result showed that the treatment using BmimCl change the surface morphology and structure of of BCF. BmimCl solution with a concentration of 5.0% and 7.5% show cause some holes in the surface of bacterial cellulose film. BmimCl solution treatment changed the structure of BCF, indicated by the increasing the peak intensity of diffractogram at a diffraction angle of 14.4° and 22.7°. Crystalline content after treatment by BmimCl with concentrations of 0%, 2.5%, 5.0%, and 7.5% were 73.85%, 73.50%, 71.33%, and 72.81%, respectively.
Effect of local sand ratio toward compressive strength and dielectric properties of concrete
Authors: Mufti N , Yohana K , Fuad A , Taufiq A , Sunaryono S
Published: August 2020

In this work, we report the effect of local sand ratio on compressive strength and dielectric properties of concrete. Concretes were made by mixing Portland cement mixed with local sand in various compositions of 1:2, 1:3.1:4.1:5, 1:6, and 1:7. These mixtures were printed in the form of 5×5×5 cm3 and have maintained (soaked) for 27 days. Specimens were characterized on the 28th day. Compressive strength was tested using the compression test and dielectric test with a series LCR meter. The compressive strength test results show that the more significant sand addition in the mixture decreases the compressive strength. Dielectric test results reveal that the higher addition of sand in the mixture reduces the dielectric constant. These results indicate that the dielectric constant measurement can be used as an alternative method for the investigation of concrete quality.
Investigation of optical properties of hybrid ZnO/Graphene-based photodetectors
Authors: Sholeha N , Lestari K D , Zulianti I , Ittikhad A A , Sofa N A , Mufti N , Kurniawan R
Published: August 2020

The problem of ozone depletion lies behind the importance of developing a photodetector device, which is used as a preliminary detection step against the risk of solar radiation. At present, hybrid photodetectors are a major concern because they have detection and operational advantages over conventional photodetectors. In this study, we investigated the optical properties and photoresponse of hybrid ZnO/graphene (HZG) systems, of which ZnO nanorod (ZnO NR) was used in the system. Investigations were carried out using spectroscopic ellipsometry (SE) and solar simulators. The results of SE fittings with the effective medium approximation (EMA) method confirmed that the length of ZnO NR was 27.81, 42.67, and 220.46 nm respectively. We note that increasing the size of ZnO NR promotes light absorption to increase significantly. Furthermore, the relationship between light absorption and HZG photoresponse was discussed using a comprehensive analysis.
Optimal power flow using particle swarm optimization for IEEE 30 bus
Authors: Widarsono K , Murdianto F D , Nur M , Mustofa A
Published: August 2020

Particle Swarm Optimization (PSO) is one of the algorithm intends to get minimum or maximum value of a function, based on the behavior of a bird flocks. In this research, PSO has implemented to overcome the problem of power flow in the plant. The search for solutions is carried out by a population of several individuals. Population is the representation of a generator in electric power distribution system. The plant used in this study is IEEE 30 bus. There are 6 plants which must be optimized. PSO generate one power value in each generator as a reference value. This value will be shifted by increasing or reducing it, until the optimal generation value is found for all plants. The result of the experiment proved that PSO is able to solve power flow optimization problems on IEEE 30 bus, indicated by the individual rate in each population, the rate of fitness and the rate of generation can reach its convergence. This convergence rate is strongly influenced by the value of Velocity on the PSO. With PSO method, the IEEE 30 bus system can generate optimal power of 193 MW.
Development of Autopilot Unmanned Smartboat Vehicle (AUSV) Based on Fishing Zone Prediction Map
Authors: Rahmat M B , Arfianto A Z , Santoso T B , Santoso T , Gunantara N
Published: August 2020

The potential of marine fish is one of the hopes for fishermen. Fishing boats have not been equipped with fish detection devices such as fish finders. To get to the location of fishing, fishermen do not know accurately the distance and direction of the ship. A fisherman only relies on experience and information from other fishermen to find out the location of the fish distribution. The ship’s fuel losses are caused by fishermen having to go around to map fishing points. Accurate data for autopilot technology is needed to move the fishing boat to the point of distribution of fish, serves to help fishermen to increase fishing yields and reduce ship fuel losses. The 70 ×16 ×15 cm3 ship prototype with autopilot technology measures the distance between fishing boats and the target location of the nearest fish distribution. This prototype is equipped with a GPS and a compass sensor that shows the direction and difference of angles to the direction of the target. This prototype has a rudder that is driven by a servo motor based on the angle difference to the setpoint. Based on the results of research and testing, this prototype can run an average distance of 15.5 m. The results of angle accuracy testing, the prototype has an angle difference. The compass angle and bearing angle are an average difference of 35.33°.
Making the post-2020 global biodiversity framework a successful tool for building biodiverse, inclusive, resilient and safe food systems for all
Authors: Gassner Anja , Dobie Philip , Harrison Rhett , Vidal Adriana , Somarriba Eduardo , Pythoud Francois , Kumar Chetan , Laumonier Yves , Chhatre Ashwini
Published: August 2020

COVID-19 has exposed the vulnerability of our economies to shocks, and it has laid bare deep inequalities in our society that threaten to derail the Sustainable Development Goals. Governments around the world are looking for recovery options that deliver new jobs and businesses. Few sectors link job creation so closely to sustainable green production as the food sector. It is the largest source of employment in many countries in the global South. At the same time cities depend upon imported food that is produced in far-away countries and shipped around the world. The trillions of dollars to be invested in recovery from COVID-19 offers an unprecedented opportunity for a clean, green and just transition to a more biodiversity-friendly agricultural and food system. Key among the political opportunities to shift the post-pandemic world towards sustainability and resilience are the ongoing deliberations of the Post-2020 Global Biodiversity Framework. The Post-2020 Framework will be the precedent for national governments to bridge economic action with the key need for a green, resilient recovery. The United Nations Convention on Biological Diversity (CBD) has traditionally seen agriculture as one of the biggest threats to biodiversity and has been actively promoting the protection of natural ecosystems by concentrating its efforts on preventing further expansion of agriculture. But it has not explicitly recognized the importance of mixed, diverse agricultural landscapes for their contribution to the conservation of wild biodiversity. The CBD has an opportunity to bring its influence to bear on international policy favouring investments in local production and marketing capacity to replace imported food and beverages. This will contribute to both COVID-19 recovery through creation of rural jobs and income and empowering governments and consumers to support diverse, mixed agricultural systems that conserve and enhance biodiversity as well as reduce greenhouse gas emissions.
Limnology in the tropics: Next steps?
Authors: Santoso A B , Toruan R L
Published: August 2020

Limnology in the tropics provides a new paradigm for inland water science, which has traditionally focused on temperate regions. Numerous studies have shown that tropical inland waters are fundamentally different from temperate systems. Warm conditions, combined with higher solar radiation and higher precipitation rates, have important consequences for biogeochemical processes in tropical waters. In addition, rapid population and economic growth has resulted in high levels of anthropogenic pressures on these systems. Such pressures have resulted in a reduction in the adequate supply of water of acceptable quality in many tropical countries and provide challenges to limnologists in terms of societal concerns and climate change impacts. Using a bibliometric approach to assessing limnological studies in the tropics, we examined how tropical limnology has barely touched the fundamental complexity that tropical inland waters have. Over 12,000 references were found and indexed by Scopus as being within the category of “limnology”. Only 335 of these were grouped under tropical studies. However, similar to those studied globally, studies from the tropics focused mainly on “lake”, “river”, “phytoplankton”, “carbon”, “oxygen”, “fish” and “nutrient”. While areas of research tended to reflect how limnologists perceive the impacts of climate change and eutrophication on lentic and lotic systems, the ecosystem services provided by inland waters and their resilience to disturbance were found to require further study.
Phytoplankton composition and abundance in the floating treatment wetlands (FTWs) system of Lake Maninjau, Indonesia
Authors: Sulastri  , Henny C , Susanti E
Published: August 2020

Algae blooms have been recorded several times in Lake Maninjau and recently in April 2018. Floating treatment wetlands (FTWs) system was installed in June 2018 in Lake Maninjau as one of the methods to reduce the risk of eutrophication in this lake. The study is to reveal the characteristics of phytoplankton composition and abundance including environmental conditions in the FTWs system in Lake Maninjau. TP concentrations tend to decrease due to nutrient dynamics such as the dilution effect of precipitation which shifting the dominant of phytoplankton composition during observation. There were two different groups separating phytoplankton composition between the inside and outside of the FTWs system. The dominant species of Aphanizomenongracile and Synedra ulnawere related to high conductivity and the TP concentration while Oscillatoriaformosa was related to the high temperature. Phytoplankton abundanceon the inside of FTWsdecreased over time compared to the outside of FTWs, while chlorophyll-a fluctuated with the average value of 6.79 µg.L−1 on the inside of FTWs and 9.54 µg.L−1 on the outside of FTWs. This study suggests that the FTWs could potentially reduce the chlorophyll-a thereby minimizing the risk of eutrophication in a tropical lake.
Aquatic plants as phytoremediator for common carp fish (Cyprinus carpio) culture
Authors: Taufik I , Setijaningsih L , Mulyasari
Published: August 2020

This research was conducted to optimize the performance of aquatic plants in maintaining water quality in common carp breeding. This study consisted of three treatments, namely: A. Lemna minor, B. Azolla pinnata, and C. Control (without plant) with three replications. The size of common carp juvenile used was ± 3 cm with a density of 150 individuals/m2. Feed was given ad satiation. The parameters observed were survival rate, weight, daily growth rate, water quality such as Biochemical Oxygen Demand (BOD), nitrogen and phosphate reduction. The research design used was Completely Randomized Design (CRD) with Analysis of Variance (ANOVA). Whereas the effectiveness of aquatic plants and water quality analyzed descriptively. The results showed that the highest survival rate and productivity of common carp breeding ponds were in treatment B, namely 86% and 463.80g. The growth rates between the three treatments were not significantly different (p> 0.05), each of which was 0.08; 0.08 and 0.09 g day−1. The BOD reduction results in treatments A, B, and C, respectively 54.65, 54.65 and 52.33%. Nitrogen reduction in each treatment was (A) 67.54%; (B) 87.37%: (C) 25.27%. Furthermore, treatment A and B did not differ in the reduction of elemental P, respectively 52.68 and 55.20%, but in C the reduction was still low at 36.75%. Optimum water quality for dissolved oxygen in treatment A, B, and C respectively 7.24; 7.57 and 3.14 mg L−1. The temperature range between treatments was 24.5 - 27.2 with a pH value of 6.00 - 6.87.
The effectiveness of integrated floating treatment wetlands (FTWs) and lake fountain aeration systems (LFAS) in improving the landscape ecology and water quality of a eutrophic lake in Indonesia
Authors: Henny C , Jasalesmana T , Kurniawan R , Melati I , Suryono T , Susanti E , Yoga G P , Rosidah  , Sudiono BT
Published: August 2020

Concerns over the impacts of floating cage aquaculture (FCA) systems on ecosystem health have led to the exploration of alternative green technologies as a way of improving water quality and preventing eutrophication problems in Lake Maninjau, Indonesia. This lake has been suffering from frequent harmful algal blooms (HABs) and hypoxic conditions due to excess nutrient and organic inputs from FCA. These have caused mass fish kills and decreased the local fish population. The main goal of this study was to assess the effectiveness of using integrated floating treatment wetlands (FTWs) and a lake fountain aeration system (LFAS) to improve lake water quality and enhance ecological conservation. The FTWs, which resembled artificial islands (AFIs) and covered an area of 23.75 m2, were planted with Echinodorus palaefolius. An LFAS was installed at the front of the FTWs. The impacts of the FTWs were evaluated from July to December 2018, while those of the LFAS was evaluated from October to November 2018. Lower nutrient and chlorophyll-a concentrations were observed within and around the FTWs and LFAS. Also, the LFAS increased the dissolved oxygen concentrations in the water to more than 100% at night. The results suggested that FTWs and LFAS could be used to prevent eutrophication and lake hypoxia. The plants in the FTWs grew much faster in the parts that were facing the waves, with their higher plant biomass suggesting that more nutrients had been removed from the lake. Also, the FTWs and LFAS, which resembled floating gardens, help to make the lake landscape more attractive and increase its amenity value. The improved water quality and habitat provision provided by these systems has attracted more local fish and other wildlife to the FTWs. The overall improvement in lake water quality and ecosystem health has the potential to ensure better provision of essential lake ecosystem services.
Evaluation of catfish performance in juvenile rearing using environmental probiotic
Authors: Yosmaniar  , Mulyasari
Published: August 2020

This research was conducted to determine the performance of catfish given environmental probiotics during breeding. Catfish used in the study had a length of 1 - 1.5 cm and a weight of 0.065 ± 0.1 grams with a stocking density of 1000 individuals per pond. The study carried out in a stagnant pond. The treatments given were: 1) using probiotic and 2) without probiotic as acontrol. The study was conducted for 60 days. Parameters measured were growth, survival and water quality. Data analysis was carried out descriptively. The results showed that catfish given probiotics had a more uniform size with an average size of 9.54 cm and 5.89 grams. Whereas catfish without being given probiotic vary in size with an average length of about 6.73 cm and weight around 2.35 grams. The weight growth of fish given probiotic was 5.83 grams with the survival rate of 85%. While fish without probiotic have a weight growth of 2.29 grams with a survival rate of 60%. Levels of ammonia in water media with Rifa probiotic better than without Rifa probiotic. Based on these results, it can be concluded that the use of the environmental probiotic showed a better performance on catfish growth than the control (without probiotic).
Experimental aquatic food chain system: Enhancing Daphnia magna as natural feed using eutrophic waters
Authors: Tanjung L R , Chrismadha T , Mardiati Y , Sutrisno  , Mulyana E , Nafisyah E , Muit N
Published: August 2020

An experimental aquatic food chain system was tested to utilize eutrophic water for producing useful natural feed. Water flea (Daphnia magna) was the main focus in this food chain system, in which it was grown on algal biomass bloom in eutrophic water, and harvested following its function as fish feed. The eutrophic waters were originated from a small lake Situ Rawa Kalong and catfish ponds located in Bogor. Daphnia was grown in an aquarium filled with the eutrophic waters from the two localities and reared without artificial feed, with an initial density of 5 individuals/L. The experiment was conducted with three replications for 19 days. Sampling was carried out five times to observe the Daphnia development. The original chlorophyll content in the aquarium of catfish pond and Rawa Kalong water were 257.64 and 211.91 mg/m3, respectively. It was observed that Daphnia consumed algal biomass to support their growth, indicated by the increase of the chlorophyll content in the water was followed by the rise of the Daphnia density to reach a maximum of 245 individuals/L at day 15 for the catfish aquarium, and then overgrazing occurred which resulted in a decrease in the chlorophyll content which was observed from day 12. The density of Daphnia in Rawa Kalong water at day 19 was 152 individuals/L and kept increasing. In the experimentation of Daphnia as natural feed, Daphnia was grown in four concrete ponds and fed with fish pellets. The Daphnia biomass was harvested when it reached a productivity of 1.67 g/m2/day. The feed conversion ratio (FCR) of fish pellets into Daphnia biomass increased with the age of the culture, with the highest value of 0.46 at day 36. Five Bada fish (Rasbora maninjau) per aquarium were then grown for 60 days, fed daily with progressive amount of Daphnia from 1.5 to 4.0 g, and the growth was compared with the control which was fed with an increasing amount of fish pellet. Fish length and weight were observed every 20 days to calculate the growth rate, weight gain, and feed conversion ratio. The results showed that the growth rate of the fish ranged from 0.24–0.98% per day. Fish pellets stimulated a higher growth in the initial phase of growth, but decreased rapidly with the fish age, while Daphnia provided a more stable growth rate. Based on its lower FCR value, Daphnia is more efficient as fish feed. Thus, Daphnia proved to be a suitable natural food source for Rasbora cultivation. Overall, our results indicated that the experimental aquatic food chain system composing of Daphnia as the first level consumer grazing on algal biomass, followed by Rasbora as second-level consumer devouring of Daphnia not only is an efficient and flexible system for reducing the nutrient level in eutrophic waters but also can support a stable growth of cultured fish.
The significance of the ecosystem value and its effect on the fish distribution in Sibau sub-watershed
Authors: Putra RAE , Aripin  , Andono A , Mahmud A
Published: August 2020

Betung Kerihun National Park (TNBK) is the largest conservation area in West Kalimantan which has an area of 816,693.40 ha with high species diversity, both flora and fauna. One of the constituent ecosystems in TNBK region is its watershed. TNBK region has four sub-watershed which acts as a receiving area and divert rain water from tributaries to the main river (Kapuas River), namely Embaloh, Sibau, Mendalam and Kapuas sub-watersheds. The objective of this study is to evaluate the sub-watershed ecosystem value which affect to distribution of the fish. The Sibau sub-watershed, one of the four sub-watersheds in TNBK plays as supporting ecosystems which have a high influence on the distribution of fish species. This zone also has a function as a site for the local people activity and become as a buffer area. Fish monitoring data in 2018 conducted on three rivers i.e. Peang River, Menyakan River and Sibau River which locateson the traditional zones show a high status indiversity. There are 25 species of fish which successfully recorded in the fish distribution monitoring with a total of 242 individuals. The common species were Batu fish (Labocheilos falcifer), Seluang fish (Rasbora voltzii), and Kenyuar fish (Luciosioma setigerum). The biophysical conditions of the river in the Sibau sub-watershed seem suitable for the habitat of many fish species. The determinant factors were water temperature, turbidity, river canopy and pH. The obtained fish can also be categorized as a bioindicators of a waters by considering of those aspects. Most of the fish species are directly or indirectly dependent on the forest or river in providing food such as plant materials (leaves, flowers, fruits) or invertebrates. Sibau sub-watershed has a rich of vegetation, as well the type of alluvial soils that make up the land. The alluvial soils have better fertility rates than other types of soils. In addition, high rainfall (2,863 - 5,517 mm/year) and dense river canopy also have an important influence on fish life in the Sibau sub-watershedwaters.
The hydromorphological characteristics of the Bonan Dolok Watershed as a basis for ikan batak (Tor spp. and Neolissochilus spp.) conservation
Authors: Ridwansyah I , Larashati S
Published: August 2020

Lake Toba Caldera is one of the most extraordinary volcanic features formed during the Quaternary geological time. Currently, Lake Toba is a multi-functional lake, which is not only used as a source of water for the Sigura-gura power plant but also a tourist destination with a high level of visits. Lake Toba catchment area is part of the landscape of the Bukit Barisan Mountain Range extending northwest–southeast with irregular ridges and valleys, which have peaks with altitudes between 2000–3000 m above sea level, dominated by slope class (3–8%). Lake Toba is also a place for Indonesian native fishes having high values such as ikan batak (Tor spp. and Neolissochilus spp.). At present, however, the fishes are difficult to find. Generally, ikan batak prefers to live in a habitat with rocky bottoms, sand substrates, clear water, slow to heavy water flow, and the river environment is mostly in the form of primary forest. Description of physical characteristics of water bodies is needed to maintain an ecological system and to be used as a basis for determining fisheries protection zones. Bonan Dolok River is one of the rivers in Samosir Regency-North Sumatra where ikan batak can be relatively found. The river flows throughout the year and its morphology, which consists of a pool, riffle, and run and flow patterns such as laminar and turbulent are favored by ikan batak. Furthermore, the upstream area which is still covered by natural forest makes this area suitable as a conservation area for ikan batak itself.
Fish distribution in Ranggeh and Batang Air Stream, Tanjung Raya, Agam District, West Sumatra Province
Authors: Dina R , Haryani G S , Nasution S H , Samir O , Lukman
Published: August 2020

Ranggeh and Batang Air Stream are two inlets of the entire channels of Lake Maninjau which are located on the southeast side of the lake with some different. Therefore, this study aims to assess fish distribution along Ranggeh and Batang Air Stream. Sampling was carried out in February, March, April and June 2019 at five stations in the Ranggeh Stream and three stations in the Batang Air Stream representing the upper section, middle section and lower section. The fish samples were caught using a scoop net and trap. Also, several parameters of water quality such as temperature, pH, dissolved oxygen, turbidity, conductivity, current, and discharge were measured in situ. Fish were morphologically identified and measured followed by statistical analysis. A total of 11 fish species were found in Ranggeh Stream, namely Aplocheilus panchax, flower horn, Gobiopterus brachypterus, Homaloptera gymnogaster, Nemacheilus chrysolaimos, Oreochromis niloticus, Osteochilus vittatus, Poecilia reticulata, Puntius binotatus, Rasbora maninjau, and Tor sp. Furthermore, five fish species were found in Batang Air Stream namely Homaloptera gymnogaster, Nemacheilus chrysolaimos, Oreochromis niloticus, Poecilia reticulata, and Rasbora maninjau. The highest number of fish species was found in the lower section of Ranggeh Stream. Homaloptera gymnogaster is a species with a minimal habitat where only found in the upper part of both streams. Water temperature and dissolved oxygen were significantly different between the upper and lower part of Ranggeh Stream. It is recommended to conserve mainly the Ranggeh Stream due to its higher fish richness through restoration act along the stream and protect the upper section as habitat for protected fish species namely Homaloptera gymnogaster.
Fundamental Frequency Anomaly Around Cimeta River, Padalarang, West Java
Authors: Fattah Erlangga Ibrahim , Januarta Gabrio Hikma , Tohari Adrin , Yudistira Tedi , Gultaf Hikhmadhan , Ipmawan Vico Lutfi
Published: August 2020

Lembang Fault segment Cimeta and Cimandiri Fault segment Padalarang assumed to coincide at Padalarang, which lies at Ngamparah and Bojongkoneng district, Bandung, West Java. Padalarang is an area with high traffic and infrastructure conditions, such as freeway overpass named Cimeta bridge, rail bridge and soon-to-be tunnel of fast train Jakarta – Bandung. The presence of these faults becomes a threat to both residents and the infrastructures. We performed an investigation of seismic microzonation using a Horizontal Vertical Spectral Ratio in the area. Microtremor measurement has been done in 37 points widespread from the Cimandiri Fault segment Padalarang to Lembang Fault segment Cimeta. The method could provide information about the fundamental frequency and amplification factor of earthquake propagation to the site from the analysis of spectral ratio microtremor data. Fundamental frequency associated with the thickness of sedimentation meanwhile amplification factor indicates the impedance contrast at the site. The result shows that the fundamental frequency of Ngamprah and Bojongkoneng area around 1-6 Hz indicated deep sedimentation. However, we found an anomaly of the high fundamental frequency of 9 Hz at the Cimeta river. Therefore, we attempted to conduct another measurement around the area at different times and conditions. Three measurements of microtremor around the Cimeta river have shown that the area has high fundamental frequencies around 9-11 Hz. These results may indicate the presence of both bedrock and geological structure of Lembang Fault at the Cimeta river.
Tsunami Preparedness Analysis for the Community of Legundi Island - Lampung
Authors: Achiari H , Gelfi M
Published: August 2020

The eruption of Mount Anak Krakatau caused massive amounts of material avalanches, which caused a tsunami in late 2018. Based on the author’s observational notes, in small Island Legundi that located in Sunda Strait waters, there were many houses, public infrastructure, and government offices that were severely damaged. In this paper, the tsunami preparedness survey was carried out through a questionnaire survey and a personal interview with victims of the 2018 Sunda Strait Tsunami. The questionnaire obtained a variety of necessary information to find out the preparedness of the Legundi Island community to face tsunami, including the demographics of victims, tsunami awareness, and evacuation behaviour. This research concludes that the coastal-community that affected tsunami in Legundi was not prepared well, both disaster and evacuation knowledge.
Comparison of Speeded-Up Robust Feature (SURF) and Oriented FAST and Rotated BRIEF (ORB) Methods in Identifying Museum Objects Using Low Light Intensity Images
Authors: Setiawan A , Yunmar R A , Tantriawan H
Published: August 2020

Museum is a place of education and learning in the field of culture and history for all levels of society. As one of the first and largest museums in Lampung, Museum Lampung presents a variety of collections that are conditional on cultural values and are very useful if they can be identified through digital media. Speeded-Up Robust Feature (SURF) and Oriented FAST and Rotated BRIEF (ORB) methods are two examples of feature extraction methods that are relatively robust for object recognition in images by finding key points. Digital media determined by the value of key points in this study are images that are classified as having low intensity with an intensity value of <2250 Lux. This study compares the two methods using the digital object media of museum objects. The image of the museum object is given treatment in terms of rotation, scaling, and cropping to test the durability of the image matching process. In terms of feature matching time, the best time is achieved by SURF with 0.16 seconds in testing of 1/3 image region. Meanwhile, the highest matching percentage was also obtained by SURF method from rotational distortion at an angle of 90 degrees which is 76.79% instead of to 63.79% of the percentage obtained by ORB.
Analysis of Generating Pico Hydro Power Plants (PLTPH) Case Study: Reservoir E Institut Teknologi Sumatera
Authors: Corio Dean , Kananda Kiki , Suhaimi Khansa Salsabila , Aziz Hilmi
Published: August 2020

The mission of the Institut Teknologi Sumatera (ITERA) is to contribute to the empowerment of the potential that exists in the Sumatra region. In line with this mission, in an effort to support the acceleration of renewable energy growth in Sumatra, labor needs to be prepared that can be used directly by students to prove theory in class, one of which is a hydroelectric power plant, with a small capacity (pico hydro) with the use of ITERA reservoir water. This paper will discuss the design of a pico hydro power plant that matches the conditions of the ITERA reservoir by modeling using Matlab / Simulink. The simulation results with a 5.46 meter head and a 0.4 m3 / s discharge obtained a power of 12.61 kW.
Unsupervised classification of three specialty coffees from Java based on principal component analysis and UV-visible spectroscopy
Authors: Suhandy D , Yulia M
Published: August 2020

In this research, we investigated the feasibility of using UV-visible spectroscopy and chemometrics to classify three specialty coffees from Java Island: Java Preanger, Java Sindoro-Sumbing dan Java Ijen Raung. Total of 300 samples of Preanger, Sindoro-Sumbing and Ijen Raung ground roasted coffees were used as samples. Samples were extracted using hot distilled water and diluted. The spectral data was acquired using a UV-visible spectrometer in the range of 190-1100 nm. Unsupervised classification based on principal component analysis (PCA) was applied for original and modified spectral data. Using the original full spectrum of 190-1100 nm spectral data, the plot score of the first and second principal components (PC1xPC2) totally can explain 90% of data variance. It was difficult to separate the origin of Preanger, Sindoro-Sumbing and Ijen Raung using original full spectrum data. However, using modified spectral data in the range of 250-450 nm, the clear separation between Preanger, Sindoro-Sumbing and Ijen Raung was demonstrated. In conclusion, it was highly potential to use UV-visible spectroscopy and chemometrics to classify the specialty coffees from Java based on its origin.