bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water entry simulation analysis of a truncated projectile
Authors: Cao M M , Wu S Y , Shao Z Y 
Published: October 2021

Abstract
In order to explore the influence of the bevel angle of the projectile on the vertical velocity attenuation characteristics and cavitation of the projectile after it enters the water vertically, this paper uses numerical simulation to analyze the bevel angles of 45°, 30°, 25° and 20°. At the same time, the high-speed camera is used to study the vertical penetration of the projectile with a 45° bevel angle to verify the simulation model. The research results show that the vertical velocity decays exponentially, and the trajectory of the truncated projectile is bent after entering the water so that an asymmetric open cavitation occurs. The bevel angle will affect the degree of trajectory curvature, velocity attenuation and the shape of the cavity. The larger the bevel angle, the greater the degree of trajectory curvature; the smaller the bevel angle, the slenderer the cavity and the smaller the asymmetry.
Effect of the kinetic energy conservation error on unsteady/steady isotropic turbulence: a numerical simulation study
Authors: Nakamura Shinnosuke , Suzuki Hiroki , Mochizuki Shinsuke 
Published: October 2021

Abstract
This study presents the effects of the conservation error of turbulent kinetic energy on the isotropic turbulence field. Here, the present research focuses on the effects on the unsteady turbulence field in addition to the steady field. This unsteady turbulence field is given by changing the magnitude of the external forcing term using a linear forcing scheme with a sinusoidal function. The conservation error is caused by using the Crank-Nicolson method, which is an implicit time integration method. This result is examined by comparing those with the results with negligible conservation error using the fourth-order Runge-Kutta scheme. For this unsteady turbulence, the period and amplitude of the external forcing term are changed as computational conditions. In contrast to steady turbulence, unsteady turbulence is shown to be affected by turbulent kinetic energy conservation error. These effects are significant when the period is short and the amplitude is large.
Wind turbine blade failure case analysis and control measures
Authors: Zhang R G , Wang B J , Wang J B , Lei H , Xia S C 
Published: October 2021

Abstract
In this paper, combined with the wind farm blade failure cases, the blade failure reasons are analyzed from the aspects of blade design, material performance, manufacturing quality, transportation and hoisting, online monitoring, wind farm operation, and maintenance. In order to prevent blade operation failure, measures and suggestions based on blade selection, supplier selection, operation and maintenance management are proposed, which provide methods for blade design, manufacturing, and production maintenance.
Germanium arsenide nanosheets applied as two-dimensional field emitters
Authors: Giubileo F , Grillo A , Pelella A , Faella E , Camilli L , Sun J B , Capista D , Passacantando M , Di Bartolomeo A 
Published: October 2021

AbstractThe IV–V groups binary compound germanium arsenide (GeAs) is a semiconductor that can be easily exfoliated in very thin nanosheets and is characterized by a band gap ranging from 0.6 eV (bulk form) up to 2.1 eV (monolayer). We investigate the field emission characteristics of exfoliated multilayer GeAs nanosheets by means of a tip-anode setup, where a nanomanipulated W-tip is positioned in front of the GeAs emitting layer at nanometric distance, all controlled inside a scanning electron microscope. We demonstrate that GeAs multilayers are suitable to develop electron sources, with turn-on field of the order of 102Vµm-1, and field enhancement factor of about 70.
Universitas Riau International Conference on Science and Environment 2021 (URICSE-2021)
Authors: Islami Nur , Linda Roza , Hermita Neni , Novitri  , Syah Dahnil , Wahibah Ninik Nihayatul , Alfuzanni  
Published: October 2021

The Universitas Riau Internationa Conference on Science and Environment 2021 (URICSE-2021) was successfully held 11 September 2021 at the Universitas Riau, Pekanbaru, Indonesia. The events brought together academia, professional and researcher and students with interests on Science and Environment, thus offering them the opportunity to share and discuss their last research and findings, as well as to facilitate and encourage their mutual cooperation. This Proceedings issue compiles oral presentations that were submitted by the authors and rigorously reviewed by a special committee.
List of Organizing Committee, International Scientific Board and Cover Page are available in this pdf.
Effect of Magnesium Hydroxide on Flame Retardant Properties for Adhesive Materials by Solution Mixing Process
Authors: Dasaesamoh Abedeen , Adair Ajaman , Matchawet Suradet 
Published: October 2021

Abstract
The objective of this research was to investigate the effect of magnesium hydroxide on the flame retardant properties of adhesive materials. The amount of magnesium hydroxide was varied from 2.5 to 10 phr. The adhesive preparation was performed by means of an aqueous filler dispersion technique. The dispersion of magnesium hydroxide in adhesive was observed by SEM images. The mechanical property of the adhesive joint was conducted by shear stress according to the ASTM D1002 standard. The flame retardant property of adhesives was measured in the horizontal burning testing method. The results revealed that the magnesium hydroxide formed agglomeration. For mechanical test, incorporation of magnesium hydroxide caused a cohesive failure in the substrate. The amount of magnesium hydroxide at 7.5 phr. possessed a maximum adhesive shear stress of 1,140 N. This was due to the magnesium hydroxide acting as reinforcing filler. The flame retardant properties of magnesium hydroxide increased with increasing magnesium hydroxide content. However, only adhesive with 10 phr was lower than 75 mm/min. The results can finally be concluded that the incorporated of magnesium hydroxide at 10.0 phr. remarkable improved the flame retardant properties of adhesive materials.
Understanding the Evolutionary Track of Tau Sco
Authors: Putra Singgih Prana , Butar-Butar Arwin Juli Rakhmadi , Putraga Hariyadi , Hidayat Muhammad 
Published: October 2021

Abstract
The τ Scorpii (τ Sco) star, was known as Al-Niyat in medieval Islamic period, is a B0V single star with mass of 15 solar mass (M⊙). It means that τ Sco is a massive star that has properties like B-type star such as has 31,440 K temperature effective and so on. The evolution simulation using MESA simulation software was conducted from pre-main sequence phase to red supergiant phase for τ Sco. We obtain that the age of τ Sco currently is 5.22 million years and it’s in main sequence phase. The τ Sco will reach the red supergiant phase at the age of 11.6 million years after formation.
Effect of Temperature on Lignin Isolation by Using Organosolv Method from Oil Palm Empty Fruit Bunch
Authors: Pramana A , Zalfiatri Y , Sari E O 
Published: October 2021

Abstract
Lignin is the second most abundant biopolymer on the earth as promising raw material for various valuable products. In terms of biorefinery, the organosolv method promotes elevate satisfy isolation due to its ease of purification and environmental friendliness. This study aimed to determine the effect of temperature on lignin isolation from palm oil empty fruit bunch (EFB) obtained through the organosolv method. The isolation was using acetic acid, formic acid, and water (30:60:10( v/v/v)) as the solvent and 0,1% of HCl as a catalyst at various temperatures (60°C, 85°C, 100°C, and 121°C). The heating temperature had significant effect on the yield, purity and pH of lignin. The lignin yield roses when the temperature increase from 60°C to 85°C but starts to decrease at 100°C. The highest yield of 15.87% was obtained at 85°C. However, the purity is inversely proportional to the yield. The higher the yield, the lower the purity correspond to condensation reaction at temperature above 85°C. The highest purity of 94.49% was obtained at the lowest yield at temperature 121°C. The heating temperature also affected pH. The pH is increase with increasing temperature. Functional groups analysis using FT-IR indicated that lignin isolates obtained at a temperature of 60°C, 85°C, 100°C, and 121°C had similar functional groups, consist of ether linkage, aromatic rings, C-H methyl linkage, guaiacyl rings, and syringyl rings indicated that the lignin of oil palm empty fruit bunch classified as SGH-type lignin.
Fabrication of Carbon Electrodes from Sago Midrib Biomass with Chemical Variation for Supercapacitor Cell Application
Authors: Farma Rakhmawati , Maurani Syarifah Famela , Apriyani Irma , Awitdrus  , Yanuar  , Rini Ari Sulistyo 
Published: October 2021

Abstract
Activated carbon with high porosity and controlled pores structure are widely applied as supercapacitor electrodes biomass derived from sago midrib (PS). Activated carbon based on sago midrib without chemical agent and using chemical agent ZnCl2 and NaOH by a concentration 0,5 M has been fabricated with a purpose to produce distribution of mesopores and micropores. Samples were carbonized at temperature 600°C using N2 gas followed by a physical activation process using CO2 gas at temperature of 700°C. The highest mass loss percentage of carbon electrode PS-ZnCl2 was 51,6% Microstructure analysis shows that amorphous structure for the activated carbon electrodes is shown by the presence of the peaks of 2θ around 240 and 440 with the highest Lc presented by ZnCl2. SEM characterization showed the domination of mesopores and a few of micropores presented by ZnCl2. EDX characterization showed the highest atomic carbon percentage is 90,27%. Specific capacitance was determined by cyclic voltammetry method and found the highest in PS-ZnCl2 was 138 F/g. The result from the physical and chemical properties, ZnCl2 is the best chemical agent from biomass-derived sago midrib for the best performance of supercapacitor cells.
Influencing Parameters for degradation of Methylene Blue using the catalyst bentonite supported manganosite MnO synthesized via facile, one-pot Sol-Gel Route
Authors: Erda Zulvi , Nurhayati  , Amirudin Erwin , Anggraini Riska , Siregar Siti Saidah , Awaluddin Amir 
Published: October 2021

Abstract
Textile industries consume considerable amounts of water in dyeing process, thus generating the enormous quantities of wastewater. The wastewater is a highly harmful to environment if discharged untreated or partially treated since it contains wide range of hazardous compounds and is also very difficult to treat. The structure of dye residues in wastewater is mostly complex polymeric structures, which is highly resistant to bio-degradation. The Fenton-based advanced oxidation process (AOP) was widely studied to treat recalcitrant organic contaminant and based on the production of OH following H2O2 activation by a catalyst. Manganese oxides are reported to be an active catalyst for degradation of a dye via Fenton process. Herein, bentonite supported MnO (MnO/bentonite) was synthesized via one-pot sol-gel synthesis and its catalytic activity was evaluated for the degradation of methylene blue (MB) using Fenton process. The X-ray diffraction results revealed the formation of the rock–salt MnO manganosite as crystalline phase of manganese oxide. The MnO/bentonite composite displayed higher performance for the degradation of MB than pure MnO. The maximum degradation of MB by MnO/bentonite composite was achieved by evaluating the process variables and compared to MnO (manganosite) as a control. In the optimum condition, the MnO/bentonite composite was able to degrade 92.97 % MB using 15 ml H2O2, 50 mg of catalyst and 25 ml MB (75 ppm) in 100 mL solution of initial MB concentration. Both catalyst concentration and H2O2 concentration seem to play a significant role for the degradation of MB using the composite MnO/bentonite.
The Utilization Silica from Oil Fly Ash as a Raw material for Paper Filler
Authors: Satriawan Alsep , Muhdarina  , Awaluddin Amir 
Published: October 2021

Abstract
Palm Oil Fly Ash (POFA) has been considered as a potential source of silica for paper filler. The objective of this work is to prepare a filler from the Palm Oil Fly Ash (POFA) to reduce disposal and waste problem. The extraction of silica from POFA can be carried out using solution of 5 M NaOH with ratio 1:5 (w/w, with respect to POFA), stirring speed of 600 rpm for 4 hours, resulting the 0.8770 M silica in Na2SiO3. The product is then reacted with Ca(OH)2 to produce paper filler (CaSiO3). The filler was characterized with Fourier Transform Infrared (FTIR), Scanning Electron Microscope-Energy Disperse X-Ray (SEM-EDX), X-ray Diffractometer (XRD) and Particle Size Analyzer (PSA). FTIR spectrum showed the formation of OH, C = O, Si-O-Ca and Si-O-Si functional groups, whereas the SEM-EDX analysis revealed the porous surface with the aggregation of needle-like morphology and contained five elements such as O (45,14%), Mg (0,85%), Si (15,65%), Ca (36,77%) and Al (1,59%). Meanwhile, XRD spectroscopy showed the presence of calcium silicate, calcite, vaterite, calcium hydroxide and quartz. Data from PSA analysis indicated that the filler has narrow particle size distribution compared with commercial fillers (GCC & PCC) and has small average particle size compared with PCC. The filler and the commercial counterparts were then applied as a paper simulation (hand sheet). Analysis of hand sheet showed that the presence of the synthetic filler in the hand sheet can improve brightness, opacity and bulk values, but slightly reduced in tensile and tearing index compared to that of PCC & GCC.
Development of Digital Simple Pendulum Learning Media
Authors: Azizahwati Azizahwati , Rahmad M. , Zamri Rifki 
Published: October 2021

AbstractThis study aims to produce a digital simple pendulum prototype. ADDIE model has been used in this study. This research was carried out up to the develop stage. The developed digital simple pendulum consists of mechanical and electronic devices. The processor used is the Arduino Uno microcontroller. The resulting prototype is declared to be functional if it meets the period and frequency equations on the pendulum. The results obtained show that: (1) the frequency and period are affected by the length of the string, (2) the period and frequency are not affected by the mass of the object. The prototype that has been produced can be an alternative learning media that leads to STEM.
Community-Based Mangrove Forest Management as Ecosystem Services Provider for Reducing CO2 Emissions with Carbon Credit System in Bengkalis District, Riau, Indonesia
Authors: Nawari  , Syahza Almasdi , Siregar Yusni Ikhwan 
Published: October 2021

Abstract
The rapid economic development in Bengkalis District has reported disrupted environmental balance. Such as mangrove forest damage, due to the intensification of wetland conversion, which is based on the emergence of industrialization. Implementing community-based mangrove forest management (CBMFM) with a carbon credit system is potential way to reduce the degradation. This management model also inline to support the achievement of sustainable development goals (SDGs). This study objective is aims to formulate a CBMFM strategy for CO2 emission reduction which registered as carbon offset project. The research design was descriptive qualitative, focusing to identify current and best management aspect of mangrove ecosystem which meet carbon project standard. The information used was secondary data that collected from relevant literatures. The formulation of sustainable CBMFM strategy was established based on the gap analysis between existing management versus expected sustainable ones. The analysis results showed that the current management was yet optimal, due to the lack of sustainable management dimensional practices, include: human, natural, and financial resources. The strategy to reduce current management gap as follows: (1) Increasing the capacity of human resources for managers and institutions; (2) Application of collaborative management; (3) Accountable budgeting; (4) Preparation of an integrated management plan; and (5) Technology management. The research result recommended as one of a reference for policymakers, in order to formulate sustainable mangrove forest management.
Flexural Capacity of Concrete Beam Reinforced with GFRP Bars
Authors: Ridwan  , Putri Dhea Triviananda 
Published: October 2021

Abstract
This paper proposes an analytical study to predict the flexural capacity of structure elements reinforced with glass fibre reinforced polymer (GFRP) bars. A nonlinear stress-strain curve of concrete is employed to consider the contribution of concrete under compression. The analytical calculation is validated against a published experiment, and the results are also compared to the ACI 440.1R-15 code. The results showed that the rupture modes predicted in the analytical study were comparable to those of the experiment, and the average ratio of flexural capacity calculated using Todeschini’s nonlinear curve to the experiment ranged from 0.78 to 0.86. Furthermore, flexural capacity obtained using nonlinear stress-strain curve of Todeschini for specimens with reinforcement ratios higher than the balanced reinforcement ratio performed better than that obtained using the ACI code.
Condition and Stability of Plantations in the Zonal Ecotone of the Forest and Steppe of the Southern Urals
Authors: Simonenkova Victoria A. , Simonenkov Vladislav S. , Kulagin Alexey Yu. 
Published: October 2021

Abstract
In the conditions of the zonal ecotone of the forest and steppe of the Southern Cis-Urals, the current state of forest ecosystems is characterized, the radial growth of Scots pine is considered as an indicator of the sustainability of plantations. Forest phytocenoses of the Southern Cis-Urals have class 2 and 3 of biological resistance, unfavorable in sanitary terms, which leads to the appearance of permanent foci of mass reproduction of insect pests of leaves and needles. These pests are actually indicators of the sustainability of the forest ecosystem. The plantations are especially strongly weakened in the zone of medium, strong and maximum anthropogenic impact on the environment. Differences in the radial growth of Scots pine are observed in the zonal ecotone of the forest and steppe. The dynamics of the radial growth of Scots pine in the Orenburg forestry indicates a decrease in the indicator over the years, which is interconnected with the dry climate of the steppe zone and partly the technogenic influence of industrial enterprises in Orenburg. The dynamics of the radial growth of Scots pine crops in the national park "Buzuluksky bor", on the contrary, increases over the years, which, in our opinion, is associated with more humid growing conditions in recent years. Comparing the average radial growth of Scots pine in the zonal ecotone of the forest and steppe, one can note higher rates in the forest zone of the national park "Buzuluksky bor" and lower rates in the steppe zone. The main method of collecting information on the state of forest cenoses was a field survey on temporary test areas, which were laid according to standard methods.
Assessment of Seismic Vulnerability of Reinforced Concrete Building Frames Based on European Macroseismic Scale (Case Study of Siak Regency Government Building)
Authors: Akbara Emiral , Djauhari Zulfikar , Kurniawandy Alex 
Published: October 2021

Abstract
Earthquake disasters in Indonesia are currently not only experienced in areas that often occur earthquakes, in areas that were once relatively safer also experienced earthquakes. The greater the strength of the earthquake in one area the greater the scope of the area affected by the earthquake. Riau Province, especially the Siak Regency, is one of the areas that are in a relatively safe zone. However, it can still experience an earthquake if the point of the earthquake is near the area itself or because the earthquake point has a very large area achievement due to the magnitude of the strength of the earthquake itself. Lately to evaluate buildings that have been standing, rapid assessment of vulnerability or rapid screening. One of the commonly used rapid vulnerability assessment procedures is that issued by FEMA. However, often the assessment of buildings provided by regulations, such as FEMA is less applicable to parties or communities not of civil engineering background, the procedures are complicated or cannot be underestimated for various disaster cases. So that academics in some countries develop vulnerability assessments that do not involve much mathematical analysis, simple, can be used by parties who are not of technical background, can be used in many countries, and can also be used for disasters other than seismic disasters/earthquakes. One such method of vulnerability assessment is the assessment procedures that are founded by the European Seismic Scale. Test results showed that vulnerability assessments could quickly be carried out by researchers with no civilian background. So that this calculation can be done by even ordinary people. This is very helpful for the assessment of the building against the damage caused by the earthquake.
The Effect of Technical Natural Rubber Mastication with Wet Process Mixing on the Characteristics of Asphalt-Rubber Blend
Authors: Bahruddin  , Wiranata Arya , Malik Alfian 
Published: October 2021

Abstract
The modification of asphalt with natural rubber is believed to enhance asphalt penetration grade (Pen Grade) 60/70. Natural rubber-type technical natural rubber with standard Indonesian rubber (SIR) 20 was chosen as an asphalt additive. However, SIR 20 as an asphalt additive directly has the rubber distribution problem in asphalt, which tends to accumulate in certain parts of the asphalt mixture. Also, the use of SIR 20 requires a very long time in the mixing process to reach homogeneity. This study aims to determine the effect of adding technical natural rubber, Standard Indonesian Rubber (SIR) 20, both with and without mastication, on the characteristics of asphalt-rubber blends. The asphalt-rubber blend was developed by melting the SIR 20 at 200 °C before mixing it with asphalt under the melting point (170 °C). Evaluation of asphalt-rubber performance is measured using tests on penetration, softening point, and Marshall stability. While the asphalt rheological characteristics reviewed are complex modulus (G*), phase angle (δ), rutting factor (G* / Sin δ) before and after short-term aging. The results showed that the mastication process of SIR 20 could accelerate the asphalt-rubber mixture's homogenization process and produce asphalt with increased performance at high temperatures. The results show the addition of 10% MSIR has the best performance with a penetration value of 58.5 dmm, a softening point of 59.1 °C, Marshall stability of 1710 kg, and rutting factor of 5.46 kPa.