bluuebunny/crossref_metadata_2025 huggingface dataset:
Responding (or not) to other’s talk
Authors: Burch Alfred Rue
Published: November 2019

This study followsIshida’s (2017)call for longitudinal studies that examine how learners in the early stages of their study abroad sojourn develop skills in responding to prior talk. Using multimodal Conversation Analysis (CA), the study compares three interactions across a six-week sojourn between a learner of Japanese and his host father. For longitudinal comparison, the study focuses on sequences in which the learner has initiated a question or comment, and the host father provides a non-minimal response. The study finds a diversification of resources and an expanded repertoire of possible actions for displaying recipiency, changing from primarily minimal response tokens that only weakly display his stance towards the prior talk early on, to the greater use of assessments and non-minimal expansions toward the end of the sojourn. The study provides evidence that short-term study abroad experiences for novice languages learners can afford opportunities for the development of interactional competencies.
Improving the physical properties of clay using Sinabung volcanic and rice husk ash with UCT and CBR
Authors: Hastuty I P , Roesyanto  , Andarai D S
Published: November 2019

Stabilization can be done by adding something to the soil in order to improve its strength and bearing capacity. One of the efforts to stabilize the soil is to add certain chemicals so that the soil will become solid. The additive materials used in this research are Rice Husk Ash (ASP) and Volcanic Ash (AGV) which is obtained from the eruption of Mt. Sinabung. The purpose of this research is to find index properties value as the effect of adding 2%, 4%, 6%, 8% Volcanic Ash and 2%, 4%, 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20% Rice Husk Ash on clay, to find the maximum compressive strenght value with UCT (Unconfined Compression Test), to find the CBR (California Bearing Ratio) value as the effect of adding the stabilization agents, and also to find the optimum content of adding Rice Husk Ash. According to the result of this research, the soil has 34.43% water content, 2.65 specific gravity, 47.33% liquid limit, 29.88% plasticity index, and 1.42 kg/cm2 compressive strength. Based on the classification system of Unified Soil Classification System (USCS), this soil is included in the group of CL which is inorganic clay with low to medium plasticity. Meanwhile based on the classification system of American Association of State Highway and Transportation Officials (AASHTO), this soil could be classified as type of soil A-7-6. The highest compressive strength value is obtained from the addition of 8% Sinabung ash and 2% Rice Husk Ash which is 3.17 kg/cm and the optimum CBR value also obtained from the addition of 8% Sinabung ash and 2% Rice Husk Ash which is 8.53%.
Building a Semantic RESTFul API for Achieving Interoperability between a Pharmacist and a Doctor using JENA and FUSEKI
Authors: Sigwele T , Naveed A , Hu Y.F , Ali M , Hou J , Susanto M , Fitriawan H
Published: November 2019

Interoperability within different healthcare systems (clinics/hospitals/pharmacies) remains an issue of further research due to a barrier in sharing of the patient’s Electronic Health Record (EHR) information. To solve this problem, cross healthcare system collaboration is required. This paper proposes an interoperability framework that enables a pharmacist to access an electronic version of the patient’s prescription from the doctor using a RESTFul API with ease. Semantic technology standards like Web Ontology Language (OWL), RDF (Resource Description Framework) and SPARQL (SPARQL Protocol and RDF Query Language) were used to implement the framework using JENA semantic framework tool to demonstrate how interoperability is achieved between a pharmacy and a clinic JENA was used to generate the ontology models for the pharmacy called pharmacy.rdf and clinic called clinic.rdf. The two models contain all the information from the two isolated systems. The JENA reasoner was used to merge the two ontology models into a single model.rdf file for easy querying with SPARQL. The model.rdf file was uploaded into a triple store database created using FUSEKI server. SPARQL Endpoint generated from FUSEKI was used to query the triple store database using a RESTFul API. The system was able to query the triple store database and output the results containing the prescription name and its details in JSON and XML formats which can be read by both machines and humans.
Computational Analysis of Water Wheel for Hydro-Electric Power
Authors: Tulus  , Marpaung T.J. , Suriati
Published: November 2019

The flow of water in the river is one of shallow water flow that has many benefits. One of them is as a power plant that uses a water wheel. Where the water wheel is used utilizing the flow of water in the river. The flow of water in the river in this study has a speed of 1.2 m/s. In the completion of this research, the finite element method in numerical approach is used to analyse the velocity of fluid motion in the river. Where speed inflow can affect electricity production. In the process, this research uses simulation with a software that works based on finite element method that is COMSOL Multiphysics 5.2 in two-dimensional form. The simulations are performed in two-dimensional flow, all the particles are thought to flow in the plane along the flow so that no flow is perpendicular to the plane. The simulation is carried out for 10 seconds and based on three variations of the water wheel height based on the center point of the water wheel is 1 m, 1.25 m and 1.5 m. Of the three variations, the fastest speed is at 1 m with maximum discharge is 34.6 m/s
Analysis of The Influence of Loading Variations Toward Brushless Direct Current Motor Performance on KARLING Electric Vehicle
Authors: Garniwa I , Nugroho M V , Noorfatima N , Sudiarto B , Orlando G
Published: November 2019

One type of electrical motors often used for electric vehicle purposes is Brushless Direct Current Motor (BLDC Motor). BLDC motor performance can be seen from its current line, electromagnetic torque, rotational speed, induction voltage, and input power as the parameters. The research’s aim is to find out the effect of loading towards BLDC motor performance on the electric vehicle. The loading variations are used in the form of passenger weight and track characteristics variations. The variation of passengers’ weight is 55 kg, 78 kg, and 143 kg. In this study obtained line current value when the passengers load 143 kg is 41.52 A. Furthermore, the values of the electromagnetic torque and energy consumption in the same weight are 23.88 Nm and 0.06 kWh/km. To ascertain the effect of track characteristics variations to the motor parameter, variations of track characteristics are done in trajectory 0° and 1.25°. The outcome is the 1.25° tilted track has higher energy consumption but lower speed.
Analysis of the Effect of the Motor Temperature to Brushless Direct Current Motor Performance on KARLING Electric Vehicle
Authors: Garniwa I , Dipantara B , Nugroho M V , Sudiarto B , Noorfatima N
Published: November 2019

Indonesia is a country that has tropical climate with average temperature vary in between 27°C until 37°C. BLDC motor industry is not common in Indonesia so that has to be imported from another country mostly subtropical countries. BLDC motor is built according to subtropical characteristics. Therefore, BLDC motor performance is changing in Indonesia due to the temperature differences. The following methods are used in the study: laboratory experiment and field test using electrical vehicle. The temperature in laboratory is in range between 23°C up to 55°C. However the field temperature varies from 27.7°C and 34, 2°C. The increasing temperature inside the motor in laboratory and field experiments conducts modification of BLDC motor parameters. The rising motor temperature degrades the current and torque of motor, but increasing the rotation velocity of the motor.
The rheometric, mechanical and morphological properties of carbon black filled styrene butadiene rubber vulcanizates in presence of alkanolamide
Authors: Surya I , Ismail H
Published: November 2019

Properties of carbon black (CB)-filled styrene-butadiene rubber (SBR) vulcanizates include rheometric, mechanical and morphological in presence of alkanolamide were studied. The synthetic rubber was filled by CB at a settled loading at thirty parts per hundred rubber (phr). The alkanolamide was derived from ethanolamine and refined bleached deodorized palm stearin and it was incorporated into CB-filled SBR at one, three, five and seven phr. From the results, it was found that alkanolamide was a rubber chemical as a co-curing and plasticizing material. As a co-curing material, it reduced the times to cure and scorch of filled SBR vulcanizates. As a plasticizing material, it reduced minimum torque or viscosity but raised the elongation at break. The properties of torque difference, tensile moduli, hardness, tensile strength and resilience of CB-filled SBR vulcanizates were also raised due to the presence of alkanolamide. The presence of a five phr of alkanolamide was the optimum concentration for CB-filled SBR whatever was tested by morphological study. The fractured vulcanizate of CB-filled SBR with the five phr of alkanolamide demonstrated greatest surface roughness and matrix tearing.
Profile Characteristics of Biomachined Zinc
Authors: Istiyanto J , Adhitama G , Zulkarnaen B A , Whulanza Y
Published: November 2019

Biomachining is one of the alternative methods in micromachining, which is environmentally friendly and have high efficiency (eco-efficient). This method uses bacteria (this research used Acidithiobacillus ferooxidans), which can extract the metal by using oxidation-reduction reactions as a part of its life cycle. This study reports the characterization of the biomachining process using zinc (Zn) materials. Pattern making was done by the visible light maskless photolithography process using DLP (Digital Light Processing) projector, and the characterization was done by varying the biomachining time. Surface profile data and photos of the workpieces were obtained using ‘SURFCOM’ and ‘Dino-Lite’ microscope, respectively. The results of this study show the profile of the surface of biomachined zinc forms a valley shaped like, with the horizontal feed larger than the vertical feed, and for the depth, width, and surface roughness tend to increase, while for the material removal rate and specific material removal rate tend to decrease with the increase of biomachining time.
Production Of Activated Carbon From Chicken Feather As An Alternative Hydrogen Storage
Authors: Alhamidi A A , Partuti T , Rachmawati D
Published: November 2019

Hydrogen is a reactive gas that requires special storage. Porous material from activated carbon can be used as an alternative storage. Activated carbon is derived from materials containing carbon. Chicken feather is one of the materials that can be used for activated carbon. There are two forms of samples, powder and briquette. The activation process is done physically with variation temperature 200, 300, 400 and 600 °C, activation time 60 minutes and flow rate of nitrogen 0.2 L/min. Activated carbon is analysed by Fourier Transform InfraRed (FTIR), Brunauer-Emmett-Teller (BET) and Scanning Electron Microscope (SEM). Percent of carbon produced is 62.90 wt.%. The FTIR results show that bond of C-H appears at 641-1362 cm−1, C-C at 1442 cm−1, C=C at 1600-1657 cm−1, C≡C at 2130-2220 cm−1. The result of BET for powder samples is 137.147 m2/gr (200 °C), 0.133 m2/g (300 °C) and 0.000 m2/g (400 °C). While for briquette samples are 77.387 m2/g (200 °C), 0.369 m2/g (300 °C) and 2.629 m2/g (400 °C). The SEM results show that pores appear on the briquette sample are much more and more visible than the powdered samples due to the agglomeration, obtained 16.01% (200 °C); 0.88% (300 °C) and 5.69% (400 °C).
Facility Location and Multi Capacity Vehicles Model for Minimizing Emissions for Environmentally Friendly Logistics
Authors: Lathifah A , Sulistyo S R , Murti I W
Published: November 2019

Transportation and distribution are two things that are closely related to logistics problems. On the one hand, these two things are at the heart of an organization or company in terms of delivering goods sold to consumers. However, on the other hand this activity can sometimes damage the environment. Emissions from fuels used in transportation and distribution activities accounted for 29.4% of the total costs incurred by the organization in logistics activities. So that, many organizations finally make environmentally friendly logistics a priority in their activities, where the goal of minimizing distribution costs and maintaining sustainability of both environments can be fulfilled. Some factors that can be improved are the determination of the location of the warehouse or depot, the combination of vehicle composition and the optimum route. Therefore, this study aims to develop a mathematical model that will optimize these three factors in an integrated manner to minimize the fuel carried out by the organization in its distribution activities with the aim of realizing environmentally friendly logistics. The expected results from the study of this research is the contribution of theoretical studies namely mathematical models of the problems raised applied to the problem of determining the location, route and combination of vehicle capacity.
The loading effect of sugarcane powder on the tensile property of glass fibre/sugarcane powder/polymer hybrid composite
Authors: Savetlana S , Sugiyanto  , Nurpratama A A
Published: November 2019

The awareness of environment enhances the use of green and renewable materials. Glass fibre reinforced composite is a well known composite material. Utility of sugarcane fibre will decrease the use of synthetic fibre without losing the excellent of mechanical properties of glass fibre composite. In the experiment, the loading effect of sugarcane powder were 5,10 and 15 wt% and glass fibre were 5,10 and 15 wt%. The hybrid composite was simply prepared by hand lay-up method. The mechanical properties was characterized using tensile test. The result show that the tensile properties of composite increased with the addition of glass fibre and 1sugarcane powder. The rule of mixture was used to model the tensile property of composite.
Dynamic Study of Reactive Dividing Wall Column to Synthesis Dimethyl Ether from Methanol Using Aspen Plus Dynamics
Authors: Wiratama I G , Hudaya T , Ferdian
Published: November 2019

In chemical industry, control system is one of the most important things to ensure product quality and safety. In designing the control system, dynamics models in the form of transfer functions are required. In a complex process the transfer functions are derived from black box models, which the relationships between input and output variables are obtained from the dynamic data. One of the complex processes that can be found in the chemical industry is reactive dividing wall column distillation (RDWC). RDWC can be used to synthesis many chemical compound, one of them is dimethyl ether (DME). DME is chemical compound which has a high economic value for it is widely used as reagent in chemical industries. In distillation column, reboiler duty and reflux rate are usually become manipulated variable (MV) and products purities are usually become controlled variable (CV). So in this study, the MVs of RDWC were reboiler duty and reflux rate, and the CVs were purity of DME at distillate and purity of methanol at side stream outlet. The goals of this study were to find the transfer functions between CVs and MVs, as well as the values of the parameters of the transfer function. To achieve this goals, dynamic simulations of RDWC was carried out by series of step test using Aspen Plus Dynamics. It was found that the response of DME purity to reboiler duty and reflux rate was more sensitive and responsive than the response of methanol to reboiler duty and reflux rate; and the responses of DME and methanol purity to reboiler duty were more sensitive and responsive than their responses to reflux rate.
3D-Modelling and Casting Simulation for The Fabrication of Megaprostheses Implant by Vacuum Centrifugal Casting
Authors: Suharno B. , Supriadi S. , Sutiyoko  , Setyawan D. , Rahmatulloh W. M. F. , Ramahdita G.
Published: November 2019

Recently, a high number of bone fracture incidents per year urges researchers in developing megaprostheses as artificial body parts. However, the complicated design and requirements for this custom-made prostheses are the key challenge. In accordance, this study focused on the preparation steps of 3D-modelling and casting simulation for the fabrication of megaprostheses implant by vacuum centrifugal casting. The reconstruction steps of 3D-modelling were started by observing the medical image data (i.e. CT-scan images). As the 3D-modelwas ready, the gating system was designed by placing two mandible bone models as the casting part with sprue and ingates where the design was respected to the gating system design for centrifugal casting. Moreover, the variation of casting part position,numbers, shapes and dimensions of the ingate, as well as the total surface area of ingates (Si) was applied while creating the gating system designsfor casting simulation. Chemically Pure Titanium (CP-Ti) with the pouring temperature and time of 1700°C and 4s, respectively, were used as the parameters for casting simulation. The solidification test results showed that the shrinkage cavities tended to decrease in volumetric scale with increasing the total surface area of the ingates, while the casting part position, number, shape, and dimension of ingate showed the difference in effectivity of the solidification of molten metal on the shrinkage cavities formation.
Reduced Remanence to Coercivity Increase Ratio of Pr11,76xDyxFe82B6 (x = 0; 1; 2; 3) Permanent Magnets
Authors: Sudrajat Nanang , Wisnu A , Manaf Azwar
Published: November 2019

Dysprosium substituted Pr-Fe-B permanent magnet samples with Pr11, 76-xDyxFe82B6 (x = 0, 1, 2 and 3) composition were made up by compacting the crystalline fine powders prepared through mechanical milling and successive high power ultrasonic irradiation. The (Pr,Dy)-Fe-B alloys with designated compositions were obtained from arc melted the charges that consisted of respectively Dy-Fe, Fe3B alloys and pure Fe and Pr metals. Results of the xrd analysis are permanent magnetic samples confirmed that the mass of the compound fraction formed is 90.07%. A change in lattice parameter of Pr2Fe14B phase occurred when Pr was partially substituted by Dy. Furthermore, the effect of dy partial substitution on magnetic properties can increase the coercivity value, but with a decrease in saturation magnetic. Dy = 3 substitution produces coercivity and remanence values of 160 kA/m and 0.275 T respectively in the permanent magnet category.
Synthesis and Deposition of High Crystallinity Cu2ZnSnS4 (CZTS) Using Dip Coating Method
Authors: Mizan Adlan , Rahman Fathur , Munir Badrul , Subhan Achmad
Published: November 2019

Kesterite Cu2ZnSnS4 (CZTS) thin film was successfully obtained using simple dip coating Synthesis of CZTS consist of mixing copper chloride, zinc chloride, tin chloride, and thiourea into a mixture of ethanol and ethanolamine to make CZTS suspension. Soda lime glass was used as a different substrate for dip coating method. Dip coating method uses 3 cycles of dip and drying at 170°C to remove ethanol and ethanolamine and then the sample was annealed at 550°C in argon atmosphere. X-ray diffraction was used to check the formation of kesterite before and after annealing. After annealing the diffraction pattern shown high crystallinity of kesterite with little secondary phase. Using Scherrer equation we can predict the crystallite size of CZTS before and after annealing. The scanning electron microscope was used to show the morphology of the CZTS before and after annealing. It is shown that although the grain was distributed homogenously a void can be seen throughout the surface. Optical properties of samples were checked before and after annealing using UV-vis Spectrometer. The result shows that dip coating method could create a good properties CZTS.
Separation of Cerium from Neodymium Hydroxide Concentrate Through Decomposition and Leaching Using HNO3
Authors: Purwani MV , Triyono  , Setyadji M , Amiliana RA
Published: November 2019

The thermal decomposition or calcination of neodymium hydroxide concentrate product by pilot plant of REOH into CeO2, La2O3 and Nd hydroxide concentrate in Center for Accelerator Science and Technology has been performed. From the result of start-up and validation was obtained neodymium hydroxide concentrate which still containing of impurities especially Ce. The purpose of this research to separate Ce from Nd(OH)3 concentrate by thermal decomposition to form Nd oxide (Nd2O3). Calcination temperature was 1000°C, and variation of time. The result of calcination were dissolved using aqueous HNO3 with molarity variation and the level of leaching was five times. From the results, it can be stated that calcination could convert Nd(OH)3 concentrate to Nd2O3 concentrate. Cerium hydroxide was easy dissolve in aqueous HNO3 while CeO2 couldn’t. The longer of calcination time, the formed of Nd2O3 is more perfect. The results of 3 hours calcination for the %weight of La increase until 12,50%, Ce increase to 10,42% and Nd increase to 52,08%. The composition of La in solid of leaching products use 1 M HNO3 with five leaching times is 3,57%, while Ce is 50.26% and Nd is 0.36%. The kinetic calcination and leaching followed reaction control.
The Role of Heat Treatment on Characteristics of Mg-Al-Sr Reinforced Nano-SiC Composite
Authors: Sartika Vioni Dwi , Trinanda Achmad Fauzi , Syarif Rama Aditya , Limouswan Ivan Orlando , Zulfia Syahrial Anne
Published: November 2019

The effect of heat treatment on microstructure and mechanical properties of SiC/Mg-Al-Sr alloy matrix composite was investigated. The heat treatment involved annealing at 425, 375, and 325°C for 4 hours, water quenching then ageing at room temperature for 48 hours. The heat treatment process caused dissolution ofs Mg2Si precipitated and decomposition of nano-SiC particles. The composites with 0.15 Vf-% nano-SiC which was treated at 425°C has reached the optimum hardness due to precipitate of the intermetallic phase. Besides, the hardness of the treated composites still has good ductility. The fracture surface of the composite consisted of numerous dimples as a result of micro voids nucleated at the interface between the matrix and SiC particles and second-phase particles as well. The fracture of heat treated composite was similar to microvoids which were nucleated mainly on nano-SiC particles as obtained during fractography analysis.
The Influence of Spray Distance of Thermal Sprayed Aluminum (TSA) on its Corrosion Resistance and Bond Strength
Authors: Riastuti Rini , Bancin Bravola A H , Rahmat Zamri , Siallagani Sonia T
Published: November 2019

This study investigates the ideal spray distance to result in a high quality aluminum coating on 316L stainless steel substrates. Thermal spray process is used using Aluminum as the coating material, well-known as TSA (Thermal Sprayed Aluminum. To get high coating quality must do the coating using proper parameters, one of them is the spraying distance. In this investigation is want to observe the influence of the spray distance on corrosion resistancea and its bond strength. the spray distance variants 10, 20, and 30cm. To evaluate the corrosion resistance and the bond strength of thermal sprayed aluminum, the researchers apply a salt spray and mechanical pull-off test. The result shows that the spray distance of 20cm produce the strongest corrosion resistance and the highest bond strength, 12.5 MPa.
Synthesis and Characterization of Biochar from Crab Shell by Pyrolysis
Authors: Nasir Muhamad , Rahmawati Triannisa , Dara Fitri
Published: November 2019

Carapace, which is part of the crab shell exoskeletons were analysed through structural and chemical methods. This material was compared between grinded and ungrinded process. This two processes resulted product called biochar. SEM-EDS, FT-Ir, XRD, TG-DSC, AAS, and PSA were conducted to characterized biochar. The SEM images showed different in biochar particles size. The composition of biochar differ for each pyrolyzed temperature, where Ca was the dominant element and C was the poor element. FT-Ir spectra provided different spectra for biochar prepared at 500-600 °C and biochar prepared at 700-900 °C. XRD data showed that calcite and lime-based biochar depend on pyrolyzed temperature. Thermal analysis generated that biochar decomposed into three main stages. Otherwise, biochar through grinded step give resemble result as like biochar without grinded step, but has smaller particle size, which means grinded process did not give significant effect both structural and chemical composition, but give any effect on particle size. Furthermore, these study indicate that biochar potentially can be used as adsorbent.
Mechanical Properties and Microstructure at Stainless Steel HAZ from Dissimilar Metal Welding After Heat Treatment Processes
Authors: Ramdan Raden Dadan , Kariem M Agus , Neswan Oki , Wiriawan Fadhil , Suratman Rochim , Widyanto Bambang , Wirawan Riza
Published: November 2019

Metallurgy of HAZ at both metals after dissimilar metal welding is important to be evaluated, because differences in metallurgical characteristics due to heating effect on bothHAZ might take place after the process. For the case of austenitic stainless steel, metallurgical aspects that should be considered after welding are the formation of chromium carbide (sensitization) and delta ferrite phase. In the present research, focus is given on the HAZ microstructure and hardness both after welding and post-heat treatment process. Microstructure observation was carried out by optical microscope and Scanning Electron Microscope (SEM), whereas hardness testing was carried out by micro-Vickers method. From this study, it can be concluded that the increase in heat treatment temperature can reduce the volume fraction of delta ferrite and chrome carbide precipitation, whereas hardness at the HAZ region decreases after the heat treatment.
Effect of the Processing Parameters on the Shrinkage Defect Using A High-Pressure Die-Casting Process
Authors: Rahmalina Dwi , Sukma Hendri , Andry
Published: November 2019

Effects of the processing parameters of a high-pressure die-casting (HPDC) process on the shrinkage defect of housing block compressor (HBC) were examined in this research. Because of the reduction of defect can increase the productivity of HBC that representing a good quality product, the processing parameters determining the quality of product must be optimized. In this study, the processing parameter of high speed in the range of 3.97 to 4.97 m/s and that of fast start point in the range of 293 to 333 mm were calculated and then the HBC samples of using the Al alloy of ADC12 were produced through the HPDC process. The shrinkage defects on HBC were characterized by visual inspection, radiography testing and microstructure examination. The result showed that the best parameters for reducing shrinkage defect of HBC by the HPDC process are 4.97 m/s of high speed and 313 mm of fast start point. The optimum parameters of high speed and fast start point were verified to contribute to producing a high quality of the HBC for the applications in automotive engine.
Relaxation Behavior of Natural Rubber Composites Through Recovery Measurement after Tension and Compression Set
Authors: Indrajati I N , Setyorini I
Published: November 2019

Relaxation behavior of natural rubber (NR) composites in term of the recovery after tension and compression set had been successfully studied. The effect of crosslink density, either physical or chemical, on the recovery percentage was evaluated. Filler carbon black N-330 and sulfur crosslinking agent were varied for this purpose. N-330 loading ranging from 30, 35, 40 and 45 phr with baseline of 2 phr sulfur. Meanwhile, sulfur loading ranging from 1, 2, 3 and 4 phr with the baseline of 30 phr N-330. Tension set was performed on constant elongation with 25, 50 and 100% strain. The measurements were performed at 100°C for 72 h. While compression set was carried out in constant deflection 25% of initial thickness, carried out both at room temperature and 100°C for 72 h. The results findings showed that the tension set was independent to crosslink densities, but greatly depended on the strain level. Low strain level provided higher recovery percentage. The filler increment markedly increased the compression set, but sulfur tended to improve it. Compression set was higher at elevated temperature since the deterioration not only generated by physical process but also by chemical oxidative thermal process.
Shape Memory Behavior Of Shape Memory Natural Rubber
Authors: Setyadewi N M , Indrajati I N
Published: November 2019

Natural rubber compound with different blend ratios of sulfur was prepared. Fabrication of shape memory polymer by swelling natural rubber compound with palmitic acid at 75 °C (100 wt% palmitic acid loading). Shape recovery experiments run by stretching to 100% (1 hour) at permanent set after heating treatment in a water bath (75°C for 30 s) and then freezing in 10°C water for 30 s. The samples were subsequently reheated in a water bath to recover the permanent shape (three stretching cycles). Shape memory compound swollen palmitic acid exhibited shape recovery of 96-100% and shape fixity 57-98%. Repeated shape recovery cycles had little effect on its shape memory property and mechanical property.
Fabrication and Characterization Of Poly Lactic Acid (PLA)-Starch Based Bioplastic Composites
Authors: Abdullah Akbar Hanif Dawam , Fikriyyah Anti Khoerul , Putri Oceu Dwi , Puspa Asri Putri Putih
Published: November 2019

In this study, to make a good bioplastic composite, starch-based bioplastic is produced by adding polylactic acid (PLA) to improve its properties. PLA was added into starch-based bioplastic with various concentrations of 0, 3, and 10 wt.%. The extrusion was performed at 90-150 °C and compression moulding process was conducted at 150 °C and pressured at 50 kgf/cm2. Bioplastic composites have been characterized to know its properties. FTIR analysis indicated shifting and increasing spectra of interaction between PLA and starch-based bioplastic. Contact angle and solubility analysis revealed that adding PLA can increase the stability of hydrophobic characteristic and insoluble properties. The combination of PLA and starch-based bioplastic can improve the mechanical properties. In addition, thermal properties of bioplastic composites have a better thermal stability and produce a lower melting point thus the energy needed to melt for bioplastic composites becomes milt as raising PLA composition. The density of bioplastics was in the range of 1.2 - 1.3 g/cm3 that would be good for light bioplastic. The results of this study showed that the combination of starch-based bioplastics and PLA at low concentration (10wt.%) potentially could enhance the properties of bioplastic composites for food packaging.
Growth of ZnO Nanorods Synthesized via Chemical Bath Deposition at Different Reaction Times and Precursor Concentrations
Authors: Sofyan Nofrijon , Panjaitan Sadra Partogi , Herman Yuwono Akhmad
Published: November 2019

The characteristics of ZnO grown via chemical bath deposition on an FTO glass substrate at different reaction time and precursors concentration have been examined. The ZnO seed was firstly spin coated at 500 rpm for 5 seconds onto an FTO glass substrate and then at 3000 rpm for another 30 seconds. The coated substrate was heated at 130 °C to remove the solvent. The growth of ZnO nanorods was performed via chemical bath deposition (CBD) at various precursor concentrations and reaction times. The morphology of the obtained ZnO nanorods were characterized using a field-emission electron microscope (FE-SEM) equipped with energy dispersive X-ray spectroscopy (EDX) to reveal the morphology and elemental composition of the nanorods, whereas X-ray diffraction (XRD) was used to examine the crystal structure. The results showed that the ZnO products have nanorod structure and sizes for each concentration. The results of this morphology were supported by the results from XRD. XRD patterns revealed that the formation of nanostructure of ZnO has been obtained at the reaction time of 2 hours, however, the optimum formation time was proven to be at 3 hours. The results also revealed that ZnO nanorods with a precursor concentration of 0.0375 M has the optimum formation of ZnO nanorod in terms of size and distribution of the nanorods.
Study of Al-Zn-Cu-Sm Efficiency for Low-Voltage Sacrificial Anode Candidate
Authors: Ferdian D , Sibuea J A , Dharmawan Y R , Pratesa Y
Published: November 2019

Sacrificial anode is one of the most effective methods for preventing corrosion in seawater environment. Aluminum (Al) anode works very well in seawater environment with high electrochemical capacity and high driving voltage. Commonly used aluminum alloy sacrificial anodes have the possibilities to trigger the occurrence of Stress Corrosion Cracking and Hydrogen Embrittlement due to overprotection on high-strength steel. The low voltage sacrificial anode was developed to overcome this problem. Electrochemical behavior of Al-5Zn-0.5Cu alloy with varied samarium (Sm) addition of 0.02 wt% and 0.1 wt% was investigated in this study. The commonly used Al-5Zn-0.02In alloy is also tested as a comparison. Anode efficiency test with weight loss method according to DNVGL-RP-B401 standard was conducted to determine the performance of Al-5Zn-0.5Cu-xSm alloy. The addition of 0.1 wt% Samarium shows the best anode performance with electrochemical capacity 2809.80 Ah/kg and 98% efficiency. Al-5Zn-0.5Cu-0.1Sm alloy is the most potential alloy to be developed as a low potential sacrificial anode to replace commonly used aluminum sacrificial anode with indium addition.
Effect of addition of OPC on Performance characteristics of Self-compacting Alkali activated slag concrete mixes
Authors: Manjunath R , Narasimhan Mattur C.
Published: November 2019

An attempt has been made in the present research to develop construction friendly, self-compacting, alkali-activated slag concrete mixes with ground granulated blast furnace slag (GGBFS) as the major source of binder material. In an effort to make the concrete mixes more eco-friendly and sustainable, by-products from Iron and Steel Industry such as steel slag sand and Electric Arc Furnace (EAF) slag aggregates, were used as the fine and coarse aggregates respectively. While the total binder content has been varied in the range of 700 – 800 kg/m3 (in increments of 50 kg/m3), all the trial mixes had a constant w/b ratio of 0.40. Different amounts of sodium silicate solutions, with specified amounts of sodium hydroxide flakes dissolved in them, are used as alkaline solutions, with the combined Na2O percentage in them varying between 6% - 8%. Test specimens were cast with mixes which showed enhanced flow-properties as per relevant EFNARC guidelines and were tested for their mechanical strength and durability characteristics. Effect of admixing of ordinary Portland cement (OPC) in smaller percentages (2.5% - 10 %, in increments of 2.5%), on the performance characteristics of this novel class of AAC mixes is evaluated. Increased cement contents are found to lead to better flow ability properties and higher strengths values with lower sorptivity values in all the Cement-Admixed, Self-compacting, Alkali-Activated Slag Concrete mixes (CASAASC mixes) tested herein. Studies with a scanning electron microscope have shown more densified morphologies developed, accounting for better performances of these mixes.
Influence of cold temperature on performance of concrete in J&K – Comparison studies
Authors: Dar A R
Published: November 2019

Cold weather concrete construction under sub-zero temperatures presents challenging problems for the professionals involved in construction industry and are the main reason for poor development of such regions. Freezing of concrete before it gains required minimum strength at early age together with considerable retardation in setting time due to freezing temperatures are the two major problems with cold weather concreting. The professionals in Srinagar, J&K also face the above problems during winter months and needs to be addressed with cost effective measures. Although there are many accelerators present in the market the performance depends on humidity and temperature changes in the region. Accordingly, a specific study related to performance of various accelerators under the average temperature range of -7°C to 7°C (prevailing during winter) was carried out for choosing the accelerator suitable for the region. The freezing and thawing effect on hydration of cement paste, initial and final setting time and strength gain were evaluated. The 3 day, 7 day and 28 day performance was compared to a standard concrete mixture without additives which served as baseline for comparison.
Phonon limited mobility in 3D Dirac semimetal Cd3As2
Authors: Amarnath R , Bhargavi K S , Kubakaddi S S
Published: November 2019

We report the numerical calculations of phonon limited electron mobility, μ in Cd3As2 three dimensional Dirac semimetal using Boltzmann transport theory over a temperature range 20<T<300K. By employing the Ritz iteration technique, we have directly solved the 3D linearized Boltzmann transport equation to obtain the first order perturbation distribution function Φ
−1(E

k
) as a function of electron energy E

k
and hence the mobility, μ. we have considered electrons scattering by acoustic phonons via deformation potential scattering and polar optical phonons. The μ due to the latter is dominating the former for T>80K, for electron concentration n
e = 1x1018cm−3. Thiscrossover shifts to lower T, with decreasing n
e. The calculations are qualitatively agreeing with the experimental results.
Improved performance of coal bottom ash co-mixtured concrete
Authors: Simran Satgurdev , Dar A R , Kumar Ravi , Adil Dar M , Raju J
Published: November 2019

The present research aims to prepare concrete by adopting coal bottom ash (CBA) as a replacement of fine aggregate. Various strength and durability tests were performed by replacing fine aggregate with CBA in percentages varying from 0-80%. To achieve workability requirement in specimens with higher CBA content, higher water to cement ratio was adopted, which lead to variation in the water absorption behaviour. The results indicated that addition of higher CBA content lead to drop in workability and plastic density. Furthermore, replacement of CBA above 40% leads to a drastic drop in strength characteristics. In addition, increasing CBA content improved drying shrinkage, standard consistency and water permeability of the concrete. Finally, the results confirmed that concrete can be effectively manufactured by judicious utilization of CBA as partial replacement of fine aggregate.
Experimental investigation on the critical heat flux of Cu-water, Al-water nanofluids for precise cooling of electronic systems
Authors: Catherine Joy R , Albert Rajan A , Brusly Solomon A , Ramachandran K , Pillai B C
Published: November 2019

In recent year’s huge development has taken place in the fields of integrated circuits technology and high speed processors. The performance of such electronic system is highly affected by heat generated during the operation. These heat generated on the electronic systems has to be dissipated in order to increase the performance and to avoid the damage due to high temperature resulting from heat generation. The increase in temperature may be reduced by the use of effective heat transfer devices such as heat pipes. The maximum heat transfer limits of the heat pipes are restricted by their heat flux limit. Critical heat flux (CHF) defines the maximum heat transfer limit. To meet the high demand of coolingin electronic industries, enhancement in critical heat flux limit of heat pipes as well as heat transfer surfaces are essential. Therefore in order to identify the ways to enhance the critical heat flux limit, series of experiment were conducted using two different types of nanofluids such as Cu-water and Al-water suspensions. For each nanofluids four different concentration were tested (0.0005wt%, 0.001wt%, 0.005wt%, 0.01wt %). There are two different type of wires were used to study the CHF. Ni-Cr wire with diameter of 0.19mm and 0.119mm, SS wire with the diameter of 0.08mm were used. The critical heat flux of Al-water and Cu-water Nanofluids is improved up to 124 % and 164 % respectively when compared with DI water.
Experimental investigation on the stabilization of soft clay using granulated blast furnace slag
Authors: Preetham H K , Nayak Sitaram , Surya E V
Published: November 2019

Soft clay is associated with a soft consistency and poor shear strength. High percentage fines lead to higher liquid limit and lower plasticity index. Low bearing capacity and excessive settlement lead to uneconomic engineering structure constructed over it. There is a serious need to mitigate this problem and hence soil stabilization is the need of the hour. In the present study, Granulated Blast Furnace Slag (GBFS) which is an industrial waste/by-product of steel industry is used as a stabilizer to improve the geotechnical property of the soft clay. Soft clay is replaced by granulated blast furnace slag in various percentages by weight (10%, 20%, 30%, 40% and 50%) and examined for its plasticity, compaction and strength properties of the mix. From the experimental investigation, it is shown that the plasticity index decreases and unconfined compressive strength (UCS) increases upon addition of slag to the soil. With the curing age, UCS value increased indicating the chemical reaction between free lime and soil. 40% slag replacing the soft clay is recommended as stabilizer as it gave the maximum increase in UCS value compared to the rest mix. Based on the laboratory work, it can be concluded that granulated blast furnace slag can be used as a potential stabilizer for soft clay and also largely solves the problem of disposal of slag.
Fabrication of Ag/AgCl electrode for detection of electric field in marine environment
Authors: Mohammed Shafeeq KK , Nair Shiny , Uma Dr. G. , Mukundan Dr. T.
Published: November 2019

Underwater Electric Potential (UEP) and Extra Low Frequency Electric field (ELFE) measurement is very important and essential for defence and civilian applications. UEP signature is produced by an underwater vessel by corrosion currents in the ship or submarine hull and also from propeller or other dissimilar metallic material in contact with the salt / sea water. The hull of the ship and the propulsion also produces a modulation of the corrosion currents, which is called the ELFE signature. The underwater electric field detection is very important to find the presence or proximity of alien, or enemy underwater targets and their positioning by non-acoustic methods, in the defence sector. The electric field in the marine environment is measured usually with sensor electrodes that are either carbon fibre or silver/silver chloride (Ag/AgCl) based. The typical sensor system uses six electrodes, mounted on three orthogonal axes. By measuring the potential the potential difference between each pair of electrode, the electric field magnitude and the direction of source can be determined.

In this study, Ag/AgCl electrodes have been fabricated by two different methods, thermal and thermal-electrolytic for the purpose of detection of marine electric field. Ag/AgCl electrodes, being reversible electrochemical electrodes, are ideal for measurement of marine electric field. Ag/AgCl electrodes have excellent electrochemical characteristics, such as very high ion exchange reaction current and lack of polarization at a low current density. The fabricated electrodes have been subjected to anodization by two different methods at constant potential and constant current, to increase the concentration of chloride ions for achieving fast equilibrium with chloride ions in sea water. The anodization process at constant potential is found comparatively more suitable in the study as it reduces the electrochemical noise associated with the electrode, the results of which are discussed. The electric field has been simulated in a tank and the characteristics of the fabricated electrodes are studied.
Investigation of utilization of Flyash in Self Compacting Concrete
Authors: Mukilan K , Chithambar Ganesh A , Azik Ahameed
Published: November 2019

The current study addresses the results of an excremental study carried out over the feasibility of utilization of flyash in the self compacting concrete with an effort to reduce the consumption of cement leading to reduced green house gas emission corresponding to the production of cement. Flyash was added on various dosages to the self compacting concrete along with the super plasticizer. Various ingredients were proportioned based on the Japanese method. The mix that passed the EFNARC guidelines were tested for the mechanical properties such as compressive strength, split tensile strength and flexural strength. Fair results have been obtained and this study unleashes a great potential for the utilization of flyash in self compacting concrete.
Effect of mineral admixtures on early age properties of high performance concrete
Authors: Poongodi K. , Murthi P. , Awoyera P. O. , Gobinath R.
Published: November 2019

In effect, the early age characteristics of concrete practically determines the performance of concrete during service. While several factors influence the fresh nature of concrete, water-binder (w/b) ratio and admixtures are particularly the most important. In this study, the effect of Nano-silica (NS) and fly ash on early strength characteristics of an M50 grade of high performance concrete was investigated. The contents of fly ash and Nano silica were used in varying proportions, from 28% to 32% and 1.0% to 2%, respectively, by weight of cement in the mix. Natural river sand was partially replaced by manufactured sand (M-sand) at 0%, 50% and 100% levels. Concrete mixture was achieved at 0.39 water/binder ratio. The workability and setting time of fresh concrete, by slump and penetration resistance tests, respectively, were determined as per ASTM C-403. The strength development at the early age was investigated and compared with that of the control concrete, based on tests on cube and cylinder specimens. Based on the obtained results, the early age strength of HPC containing NS was improved than the results obtained using the IS: 456-2000 code recommended models.
Numerical Investigation of Square Ring Shape Force Transducer
Authors: PratapSingh Ajay , Kumar Ghoshal Sanjoy , Kumar Harish , Kumar Rai Ajay
Published: November 2019

With growing industrial needs, there has been consistent thrust over the development of simple shaped force transducers. Some of the shapes designed may be analyzed through the analytical methods or conventional theorems. But, some of the newer shaped developed recently or proposed are not been able to analyzed through analytical methods, insist the application of modern computational tools like finite element analysis to be implied and applied in rationalized manner to have effective outcome regarding design analysis and other parameters. The present study attempts to discuss the procedure and outcome of finite element analysis for a square ring shaped force transducer for the material Al 7075 with a nominal capacity of 5 kN. The paper discusses details of the approach and salient outcome. The paper further cites the implications of the finite element analysis in design and development of the force transducer. The software ANSYS has been used to carry out the present study.