bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fe-N/C Catalyst using Various Nitrogen and Carbon Ratio through Chemical Oxidative Polymerization
Authors: Setyowati VA , Widiyastuti W , Nurkhamidah S , Saidatin N , Lukdyantoro O 
Published: December 2021

Abstract
This study aims to explain the effect of variations in nitrogen and carbon composition of catalysts on electrochemical properties and physical characterization. The usage of non-precious metals supported by nitrogen-carbon is one alternative to reduce the amount of platinum as the innovation of energy materials. Iron is a transition metal that can increase catalytic activity with the addition of a nitrogen source. The polymerization process was carried out by chemical oxidative polymerization for 24 hours in an ice bath using aniline as N source. Optimization of nitrogen coating on the carbon surface is carried out by mixing carbon during polymerization. The mixing of iron precursor and N/C powder was carried out in an ultrasonic bath and continued with pyrolysis at a temperature of 700°C. Regarding Cyclic Voltammetry (CV) test, the Fe-N/C = 2/1 catalyst has the largest area and the highest current density. The presence of Fe2O3 is needed to improve the electrochemical properties compared to Fe3C compounds. The composition analysis showed that the Fe-N/C = 2/1 catalyst had the highest Fe content after pyrolysis. In addition, the Fe-N/C = 2/1 catalyst also had the highest nitrogen content which can form a nitrogen functional group from the pyrolysis process.
Hydrothermal Pretreatment of Rice Straw with Alkaline Addition for Enhancing Biogas Production in Semicontinuous Anaerobic Digester
Authors: Sato A , Widjaja A , Soeprijanto  
Published: December 2021

Abstract
This study presents the results of hydrothermal pretreatment of rice straw on its ability to improve the biogas production process in anaerobic digesters. Hydrothermal treatment on rice straw biomass was carried out with the addition of 0%, 3% and 5% NaOH (w/w rice straw) for one hour at a temperature of 140 °C. This study showed that hydrothermal and alkaline hydrothermal pretreatments were able to increase organic degradation of rice straw as indicated by an increase in the dissolution of lignin and hemicellulose from rice straw. Temperature and NaOH worked synergistically to dissolve lignocellulose in the hydrothermal pretreatment process. In the semicontinuous digester fed with pretreated rice straw, NaOH content in the pretreatment stage was found to give significant effect in enhancing biogas production. Average daily biogas production by the untreated rice straw, hydrothermal pretreated without NaOH addition, hydrothermally treated rice straw with 3% NaOH and 5% NaOH was 23.9, 57.1, 95.8 and 108.8 L/kg rice straw, respectively.
Numerical Investigation Aerodynamic Characteristic Installation I-65° Cylinder Type Upstream Bluffbody as Airflow Passive Control
Authors: Sakti G , Cahyo B G , Wulansari A , Regia A , Dharma I A 
Published: December 2021

Abstract
This report is the basic research that focuses on efforts to reduce the drag force of a cylindrical pipe by placing an interfering cylinder in the area of the incoming flow direction. The aerodynamic behavior of the central cylinder and its disturbances were modeled in 2D are discretized in laminar flow by Finite Volume Methode using Ansys Fluent®. Efforts to reduce the drag force are carried out with the main cylinder diameter D=60 mm and the interfering cylinder type I-65° with diameter d/D = 0.125. The distance between the center points of the two cylinders being s/D=1,4 and Reynold number Re = 5.3 x 10

4
at a speed of U∞=14 m/s. Numerical simulation using variations of turbulent models k-epsilon (2eq),
k-omega (2eq), and transition k-kl-omega (3eq). The results of this research can show better aerodynamic performance. Placing the cylinder I-65° in tandem can reduce the average drag force coefficient by 68% at 700-800 timesteps. In contrast, the average lift coefficient decreased by 13% at the same timestep. The results were obtained with transition k-kl-omega (3eq) turbulence models that have been validated and able to approach the referenced experimental data.
Steady State Thermal Effect on Static Characteristic of Copper Roller Shaft
Authors: Marliana E , Utomo G P , Fuad S , Arifin A A 
Published: December 2021

AbstractThe static analysis of a copper roller shaft is performed. The copper roller shaft consists of bushing, pen roll and roller. All of those components g4bconsist of different materials. Thermal steady state and statical analysis is performed in order to investigate the thermal effect of high temperature copper slab on the roller shaft. The copper slab temperature is 1200OC. Based on this work obtained that the maximum total deformation is 0.0050523 m, maximum equivalent stress is 41600 MPa, maximum life cycle is 1011, total heat flux maximum is 879910 W/m2and the maximum damage occur in the pen roll component.
Functionalization of Multiwall Carbon Nano-Tube Supported Zinc Oxide Solid Acid Catalyst Using Sulfonate Compound for Transesterification of Schleichera Oleosa L Oil
Authors: Asri N P , Saraswati R , Yogasuara R R , Puspitasari D A , Mirzayanti Y W , Udyani K , Suprapto  
Published: December 2021

Abstract
Biodiesel is an alternative energy obtained through the trasesterification of vegetable oil in the presence of a catalyst. The catalyst plays a very important role in the success of the transesterification process. One way to increase the activity of the catalyst is through chemical modification called functionalization, which generally using SO3 group as a sulfonating agent is known as the sulfonation process. However, the disadvantage of this process is that it uses strong acids which are corrosive, require high temperatures and are not environmentally friendly. This study aims to increase the activity of zinc oxide catalyst supported by multi-wall carbon nano tube (Z/MWCNTs) sulfonated using (NH4)2SO4 as sulfonating agent. The synthesis route includes co-precipitation, sulfonation and precipitation time. The effect of concentration of ammonium sulfate, co-precipitation time, and sulfonating time on yield of biodiesels of kesambi (Schleichera oleosa L) oil (OSOBD) was investigated. The result showed that the activity functionalized Z/MWCNTS catalyst (Z/s-MWCCNTs) could enhance significantly. The results of the catalyst activity test on transesterification of OSO into biodiesel showed that Z/s-MWCNTs gave a high yield of 91% for the functionalized catalyst using ammonium sulfate with a concentration of 35%, co-precipitation time 12 hours and sulfonation time 4 hours. The functionalization of MWCNTS with the sulfonation process using ammonium sulfate has the potential to increase catalyst activity and can increase the efficiency of the transesterification process for non-edible oils, especially kesambi oil.
Designing Open Channel Dimension for Imkasu Area West Papua
Authors: Sari A S , Cahyono Y D G , Johnson N N A , Simorangkir D , Redanto F A , Putri R H K , Utamakno L 
Published: December 2021

Abstract
Gag Nikel Ltd belongs to a Contract of Work located in Gag Island, West Waigeo Islands District, Raja Ampat Regency, West Papua Province. The open pit mining system employed at this company will enter the mining location and therefore, requires a design of open channel for diversing water coming from rainfall, run off, and ground. The rainfall intensity calculated by Mononobe formula obtained 5,994 mm / hour, whereas the catchment area got 0.59 km 2. The total discharge of run off calculated by Rational Formula gained 1867,956 m 3 / hour. Meanwhile, the design of open channel calculated by Manning Formula yielded wet section (A) = 0.668 m 2, base width (b) = 0.714 m, and depth (h) = 0.714 m, surface width (B) = 1.542 m. Box control having the volume 1 m3, length = 1 m, width = 1 m, and height 1 m must be made every 1 kilometer of open channel length. Around the area of open channel, the used tire must be given to reduce the erosion rate flowing into settling pond. All of these are necessary because the open channel is located near the natural channel and we must also consider several regulations such as Presidential Decree and IPPKH adjusted to the technical study that has been designed.
Quantitative Model of Optimization on Non-Oil Based Fuel Alternative Energy
Authors: Sutejo B , Oktavera R 
Published: December 2021

Abstract
Research of “Quantitative Model of Optimization On Non-Oil Based Fuel Alternative Energy” is using goal programing method approach which will generate comprehensive mathematic models to determine policy on alternative energy field beside oil based fuel. The result of the research is sensitivity analytic model and optimization model of nonoil based fuel alternative energy. Developed model is goal programing to optimise alternative energy beside oil based fuel. Model implementation conducted on alternative energy are coal, nature gas and hydro. And the calculation result using Expert Choice Version 9.0 is obtained that coal as alternative energy has relative priority value of 36,8% at overall consistency index 0,04 or 4%. Optimization implemented model conducted at alternative oil based energy plan using calculation of Quantitative System 3.0 program conclude that coal = 9.809274, gas = 0.8409028, hydro = 0. Minimal objective = 18.69225
Rheological properties of sewage sludge ash ceramic masses
Authors: Shakhov S A , Yu Nikolaev N 
Published: December 2021

Abstract
Industrial wastes are widely involved in the building ceramic production. Sewage sludge ashes are promising secondary sources for building ceramics production. However, sewage sludge ash application for building ceramic materials production is limited by unsatisfactory molding properties. According to modern concepts, coagulation structure formation processes can be controlled by adjusting ceramic mass compositions by highly dispersed modifying additives. In this study, the drinking water treatment sludge filtrate generated in pumping and filtering stations was used as a highly dispersed additive. The purpose of study was to assess the drinking water treatment sludge filtrate effect on rheological properties of ash-clay molding mixtures.
Using the photo sedimentation analysis, X-ray phase analysis, calorimeter method and parallel-shifting plate plastometry the drinking water treatment sludge filtrate additive effect on rheological properties of ash-clay mixtures was established.
It was found that ash-clay mixture modification with the drinking water treatment sludge filtrate promotes a slow elastic deformations percentage increase from 3-17% to 7-34%. Apparently, this is due to the drinking water treatment sludge filtrate highly dispersed particles adsorption on coarse ash and clay particles that promotes the growth of their hydrophilic properties. Ash-clay mixtures molding properties improvement makes it possible to increase the ceramic blanks density.
Method for assessing the effect of self-healing of asphalt concrete with encapsulated modifier
Authors: Inozemtcev S S , Do T T , Korolev E V 
Published: December 2021

Abstract
A unified methodology for assessing the ability of a material to heal itself does not exist at present. It is due to the absence of criteria characterizing the ability of a material to independently respond to conditions in a controlled manner and to take measures to eliminate an adverse effect on the properties or structure of the material. Usually, the self-healing ability is assessed using the coefficient of relative change of a measured indicator (for example, strength), which does not allow for two parameters: residual strength, which depends on the number of not broken bonds after the test, and the binder’s own potential for recovery. The paper proposes a method for calculating the healing efficiency, taking into account the relative difference in the loss of strength, material with the use of an encapsulated modifier and without it. The proposed recovery factor reflects the effect of the encapsulated modifier on the change in the strength of the composite under study; therefore, to assess the efficiency of a self-healing material, it is also necessary to take into account the properties in the initial period of time and their stability under operating conditions. The problem of choosing the optimal indicator of material properties for assessing the recovery effect and improving the calculation method taking into account the duration of the recovery period is not solved and requires additional large-scale studies.
Applicability of X-ray computed tomography for concrete cellular structure analysis
Authors: Lebedev M S , Kozhukhova M I , Voitovich E V 
Published: December 2021

Abstract
Nowadays, the researchers of materials sciences area, use direct and indirect methods such as microscopy, porosimetry, etc. for studying structural characteristics of materials. X-ray computed tomography is among one of the modern and widely used research analytical methods that provides 3D images of solid materials without any preliminary preparation, such as crashing of sample, and violation of its structural integrity. To demonstrate the potential possibilities of X-ray computed tomography, in this research matrices with cellular structure using portland cement-based cellular concrete was studied as an example. The study showed that the pore structure of cellular concrete is dominated by capillary pores with a diameter of up to 200 um. The majority of pores did not exceed 1.6 mm in diameter, that formed during the foaming process. The calculated average size of the volumetric distribution of air voids was 0.95 mm. About 80% of large pores of a cellular concrete specimen with an average size of about 1 mm determines high porosity of the composite which is consistent with its average density values. The study of interpore structure partition using X-ray computed tomography allows for evaluation the difference in thickness from 10 um to 0.6 mm in the zones of “confluence” of large pores. The porosity of cement matrix, including individual pores with sizes from -30 to 250 um, was about 16.5%. The cement matrix is dominated by the products of cement hydration with capillary and “gel” pores. There are few nonreacted cement particles that are evenly distributed throughout the volume of the composite. To obtain more complete information about the structure of cellular concrete or any other composite, it is necessary to perform complex studies applying not only X-ray computer tomography technique, also scanning electron microscopy for evaluation of chemical analysis to identify mineral phases present and correlate them with absorption intensity of X-ray radiation on tomographic images.
Development of structural-heat-insulating lightweight concrete composition using production of aerated concrete waste as a porous aggregate
Authors: Leontev S V , Kharitonov V A 
Published: December 2021

Abstract
Annually enterprises in the field of manufacturing of products from aerated concrete generate from 5000 to 10000 m3 of solid production waste. One of the perspective and under-investigated direction is the practical application of solid waste using a porous aggregate in structural-heat-insulating lightweight concrete in the production of construction materials. The aim of this study was to evaluate the possibility of using crushed aerated concrete as a large aggregate in lightweight concrete for structural and thermal insulation purposes and to establish optimal conditions for obtaining products with the best characteristics. There were defined the qualitative indicators of crushed aerated concrete, analyzed factors influencing on the preservation of the properties of concrete in time, selected the composition of concrete aggregates from crushed concrete, studied the structure and properties of the obtained samples in the research. It has been found that to obtain effective constructive insulating lightweight concrete using waste production of aerated concrete as an aggregate is possible due to the fractionated pre-treatment of the aggregate with water dispersion of deep-penetration acrylic copolymers, insertion excess sealing water to concrete mixture, including optimization of the rheological properties of the concrete mix due to insertion of polycarboxylate hyperplasticizer.
Microstructure evolution and phase transformation of ZrB2-45MoSi2-10Al coating at high temperature
Authors: Kovaleva M G , Yu Novikov V , Vagina O N , Sirota V V 
Published: December 2021

Abstract
The ZrB2-45MoSi2-10Al coating was prepared by a Robotic complex for detonation spraying of coatings equipped with a multi-chamber detonation accelerator on surface of carbon/carbon composites without adhesion sublayer. The coating has a lamella-type structure typical for gas-thermal coatings, well connected with C/C composite substrate without sublayer, and composed of m-ZrO2, t-ZrO2, t-MoSi2, some h-ZrB2, and c-Al phases. Heat treatment of the samples at 1500 °C for 1, 3 and 6 h was carried out in air. The effect of heat treatment on the microstructure and phase composition of the ZrB2-45MoSi2-10Al coating was investigated by X-ray diffraction and scanning electron microscopy. The c-ZrO2 and h-(α-Al2O3) were formed after oxidation at 1500 °C for 6 h. The uniform distribution of ZrO2 ceramic particles and the formation of a-Al2O3 enhanced the thermal stability of the coating. The coating after heat treatment (1, 3 and 6 h) exhibited structure without cracks and low porosity. The dense microstructure of the coating contributed to its good oxidation-resistant property at high temperature.
Influence of electron radiation on the physical and mechanical properties of a nonwoven fabric made using Spunlace technology
Authors: Yu Galimzyanova R , Lisanevich M S , Khakimullin Yu N 
Published: December 2021

Abstract
The effect of electron radiation on the physical and mechanical properties of Sontara nonwoven fabric produced using spunlace technology has been studied. The initial raw material for the manufacture of materials using this technology, as a rule, are viscose, polyester, polypropylene and cellulose fibers. Such nonwovens are highly breathable and are therefore used in disposable surgical gowns and suits. Since radiation can be used to sterilize disposable surgical gowns, it is important to assess the resistance to ionizing radiation. It was found that the Sontara brand material is resistant to the effects of ionizing radiation - the physical and mechanical characteristics of the material (breaking load and relative elongation) in the longitudinal and transverse directions of the web do not significantly change when irradiated with absorbed doses up to 60 kGy. It should also be noted that a cloth with a basis weight of 68 g/m2 has a significant smell of strength after radiation sterilization.
Evolution of the phase composition of ZrB2-35MoSi2-15Al composite coating at annealing
Authors: Goncharov I , Kovaleva M , Yapryntsev M , Sirota V 
Published: December 2021

Abstract
In this article, new composite coatings ZrB2-35MoSi2-15Al were deposited on the surface of a carbon-carbon composite using a multi-chamber detonation accelerator. The evolution of the phase composition of ZrB2-35MoSi2-15Al coatings was analyzed with differential scanning calorimeter (DSC) and X-ray diffractometry (in situ HT-XRD) at temperatures from room temperature (∼ 25°C) to 1400°C (normal atmosphere and pressure). The coating before annealing according to X-ray diffractometry data is tetragonal (t-ZrO2) and monocline (m-ZrO2) zirconium dioxide, monocline silicon oxide (m-SiO2), hexagonal zirconium diboride (h-ZrB2), tetragonal molybdenum disilicide (t-MoSi2), cubic aluminum (c-Al) and cubic yttrium oxide (c-Y2O3). It was found that the coating crystallizes in m-ZrO2 at 460ºC, and then mullite with rhombic crystal lattice appears at 960ºC. When the temperature reaches 1050ºC the m-ZrO2, ZrSiO4, t-ZrO2, m-SiO2 and mullite phases formed in the coating. At 1400 º C, cubic zirconium dioxide appears in the coating. Experimental results can become the basis for the application of ceramic coating ZrB2-35MoSi2-15Al, which can improve the properties of carbon-carbon composites in an oxygen-containing environment at elevated temperatures.
Lime compounds for restoration and decoration of building walls
Authors: Loganina V I , Zaytseva M V , Uhaeva T V 
Published: December 2021

Abstract
Information on the effect of a polysilicate solution obtained by mixing liquid glass with a silicic acid sol on the structure formation of lime compositions is presented. It was revealed that the amount of specific heat released when lime is wetted with a polysilicate solution is greater than when lime is wetted with water. This is due to the additionally released heat due to the chemical interaction of lime with polysilicate solution. It was found that the introduction of a polysilicate solution accelerates the development of plastic strength. For comparison, we used liquid glass and a sol of silicic acid as an additive. The synergistic effect of the influence of the polysilicate solution on the structure formation of lime finishing compositions was established, which manifests itself in the acceleration of the set plastic strength in comparison with silica sol and water glass. It has been established that the introduction of a polysilicate solution into the lime mixture formulation contributes to an increase in the resistance to slipping of the finishing layer. The optimal thickness of the finishing layer was determined, which is 20 mm, at which sliding from the vertical surface is not observed.
Soil bases modified with lime waste and polycarboxylates
Authors: Zakrevskaya L V , Nikolaeva K A , Gandelsman A I , Orekhov P A 
Published: December 2021

Abstract
Increasing the volume of road construction is one of the priority areas of infrastructure development in any country. When building roads, it is preferable to use local materials to reduce the cost of their transportation, therefore, it is advisable to build the roadbed on local soils. It is worth noting that clay water-saturated soils are the most common, which complicates the construction of the road due to some features of this type of soil. The object of the study is a water-saturated clay with the following characteristics: natural humidity from 25.3 % to 28.1% by weight, optimal humidity from 11.8 % to 16.7% by weight, the number of plasticity from 0.118 to 0.153. Clay soils have a number of features: waterlogged soils are difficult to compact and develop, it is quite problematic to dry them, and thixotropy is also characteristic of clay soils. In this regard, it is most advisable to use the method of complex mineral binders to optimize their physical and mechanical properties. In the course of laboratory studies, compositions of soil compositions with the addition of lime waste and superplasticizer P-17 were developed. The dependence of the strength on the consumption of mineral binders and surfactants is established: the maximum compressive strength of the soil being fixed is achieved at a lime content of 25 wt.% and at a P-17 content in the range of 0.10-0.5 wt.%.
Thermal Conductance of Epoxy/Alumina Interfaces
Authors: Yang Wei , Chen Yun , Zhang Yipeng , Fu Yongsheng , Zheng Kun , Wang Kun , Ma Yongmei 
Published: December 2021

Abstract
The interfacial thermal conductance (ITC) between filler and polymer matrix is considered as one of the important factors that limits the thermal conductivity of thermally conductive polymer composites. The effect of two different surface treatments (piranha solution and plasma) on ITC of epoxy/alumina was investigated using Time-domain thermoreflectance method (TDTR). The TDTR results show that compared with non-treated samples, the ITC of samples treated by piranha solution and plasma increased 2.9 times and 3.4 times, respectively. This study provides guidance for improving the thermal conductivity of thermally conductive polymer composites.