bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photocatalytic Performance of Bismuth Oxide Prepared by Citric Acid-Fueled Solution Combustion on Decolorisation of Organic Dye Molecules
Authors: Astuti Yayuk , Anggraeni Dhina , Darmawan Adi 
Published: July 2020

Abstract
Bismuth oxide can be applied as photocatalyst. The purpose of this study was to synthesize bismuth oxide using the solution combustion method, identify the characteristics of bismuth oxide using FTIR and XRD, and determine the photocatalytic activity of the obtained bismuth oxide to decolour Remazol Black B and Rhodamine B dye molecules. The results showed that bismuth oxide was formed with yellow colour after calcination convinced with the presence of Bi-O and Bi-O-Bi functional groups and having 95.38% similarity using Match software. The photocatalytic activity test shows that the obtained bismuth oxide enabled to decolour RBB, RhB dyes well.
Coordination Polymers Containing a Glycine-Derived Trimellitic Acid Imide
Authors: Beards Michael J. , Turner David R. 
Published: July 2020

Abstract
A trimellitic imide ligand (GlyTMI2-), derived from glycine, has been used in the formation of three coordination polymers as a means towards understanding the role of the aromatic core of the ligand in determining structure. The polymeric structures poly-{(N(CH3)2H2)[Zn2(GlyTMI)2(OAc)(DMF)0.5(CH3OH)0.5]·CH3OH} (1), poly-[Cd2(GlyTMI)2(DMF)3] (2), and poly-{[Cd2(GlyTMI)2(4,4’-bipy)2]·2H2O·DMF} (3) have different dimensionalities, attributed to the change in size of the metal ion (Zn vs. Cd).
Synthesis of Copolymer of Chitosan with Acrylamide as an Adsorbent for Heavy Metal Waste Treatment
Authors: Desnelli D , Eliza E , Mara A , Rachmat A 
Published: July 2020

Abstract
The aim of this research is to chemically modify chitosan to improve and enhance the ability as an adsorbent. Chitosan is a natural polymer produced from chitin deacetylation. The best performance of chitosan is as an adsorbent is in acidic solutions. Chemical modification was carried out by chitosan copolymerization with acrylamide. Copolymer synthesis was done by using microwave oven with the weight ratio of chitosan and acrylamide of 1: 4. The characterization of chitosan copolymer with acrylamide (chitosan-g-acrylamide copolymer) was conducted by FTIR spectroscopy and Scanning Electron Microscope (SEM). The analysis of the functional group by FTIR spectroscopy shows that the copolymer has been successfully synthesized. The surface analysis with SEM shows that the morphology of the copolymer surface is more homogeneous compared to that of chitosan.
A Green Method to Prepare Composite of Graphene Oxide-Manganese Oxide using a Modified Hummer’s Method
Authors: Gros Marselus Jeques , Masruri Masruri , Tjahjanto Rachmat Triandi 
Published: July 2020

Abstract
A composite graphene oxide-manganese oxide (GO-MnO) was facilely fabricated in one-step preparation by modified Hummer’s method. The Hummer’s method for graphene oxide preparation produced manganese residue as by product, therefore, we modified the Hummers method to convert the manganese residue into value-added materials with aqueous sodium hydroxide (NaOH). The number of Mn on composite and surface chemistry was investigated. GO-MnO was characterized by atomic absorption spectroscopy (AAS), UV-Visible spectrometer, fourier transform infrared (FT-IR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Quantitative measurements showed that GO-MnO 1 and 2 have the number of Mn of 1.4231 and 2.0958 μg/g, respectively. FTIR showed the presence of functional groups such as hydroxyl, epoxy, carboxyl, carbonyl and manganese oxide. XRD confirmed the interlayer spacing of GO-MnO synthesized by our techniques is lower than GO-MnO produced by other processes. TEM showed that GO-MnO is single layer yet and Mn species was not homogeneously distributed on composite.
Synthesis and Characterization of Pectin Membrane as a Matrix for Curcumin Sustained-Release
Authors: Hastuti Budi , Kurniawati Maulida 
Published: July 2020

AbstractThis study aims to synthesize pectin membranes, characterization of pectin membranes use FTIR, XRD, SEM, and to see the loading of curcumin in pectin membranes as a drug delivery system by contact time variations. Pectin membrane synthesize by dissolved 0.5 gram of pectin powder in 25 ml of 2% acetic acid solution then stirred for 1 hour. The solution is molded in membrane mold then oven for 24 hours at 50°C. Pectin membranes were characterized by FTIR to determine functional groups, XRD test to determine crystallinity, and SEM test to determine the surface morphology. The loading of curcumin in pectin membrane are carried out by contacting the pectin membrane into 100 ppm curcumin at various times of 5 to 120 minutes. Determination of curcumin concentration contained in pectin membrane use UV-Vis spectrophotometer at λ 426 nm. The results showed that the produced of pectin membrane was thin, pellucid, and homogeneous sheets. The results of FTIR characterization showed OH group at wave number 3448.72 cm−1and carbonyl group at wave number 1604.77 cm−1. XRD characterization result showed that the pectin membrane was amorf. SEM characterization results showed smooth and flat surface morphology. The optimum contact time in loading curcumin proses in pectin membrane was 60 minutes with a loading percentage of 10%.
Synthesis of ZnO-Ag Nanocomposites trough Ultrasonication-Microwave Combination Method with Clove Leaf Oil
Authors: Hisbiyah A , Nisyak K , Prasetya Y A , Iftitah E D , Srihardyastutie A 
Published: July 2020

AbstractZnO and Ag nanoparticle have known their antibacterial activity especially their use in medical materials. In this study, ZnO-Ag Nanocomposite was synthesized by ultrasonication-microwave combination method with variation of reaction time using clove oil as their bioreductor. ZnO-Ag was prepared from ZnO Acetate as a source of ZnO and AgNO3 as a source of Ag. The crystallinity structure, average particle size, morphology, and composition of ZnO-Ag was characterized by X-Ray Diffraction, Scanning Electron Microscope, and Energy Dispersive X-ray Spectroscopy. X-ray diffraction pattern indicates that reaction time of 30 minutes have optimal synthesis results. The nanocomposite obtained consists of 43.2 % Ag nanoparticle, 17.5 % hexagonal Zincite, 14.6% Zinc Oxide, 14.5% wulfingite (deuterated), and 10.2% Zn(OH)2 with average particle size of 28.29 nm according to Scherer’s equation. The result of scanning electron microscope showed that ZnO has an fiber shape and Ag has a round shape.
Characterization of alginate-chitosan membrane as potential edible film
Authors: Ismillayli Nurul , Hadi Surya , Tri Dharmayani Ni Komang , Sanjaya Rochmad Kris , Hermanto Dhony 
Published: July 2020

Abstract
Alginate-chitosan based biopolymer for possible application as edible film coating has been studied. Alginate hydrosol and chitosan hydrosol with mass ratio of 1:1 were mixed to form a thin membrane and then dried. The obtained alginate-chitosan membrane was confirmed using FTIR spectrophotometers. Characterization of the membrane, which includes thickness, tensile strength, water vapor sorption, resistance to pH change and antimicrobials properties, were conducted. It was showed that the interaction of alginate and chitosan in the membrane occurred through the electrostatic interaction of the carboxylic group of alginate and ammonium groups of chitosan. At the same thickness, the alginate-chitosan membrane tensile strength was higher and more resistant to pH changes than both native alginate and chitosan membranes. Furthermore, the alginate-chitosan membrane has good antibacterial potential against gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli). It is expected that the alginate-chitosan membrane has the potential application for safe and efficient fruit coating.
Hydrothermal synthesis of titanium dioxide nanotube with methylamine for photodegradation of Congo red
Authors: Leong C Y , Koh P W , Lo Y S , Lee S L 
Published: July 2020

Abstract
Titanium dioxide (TiO2) nanotube photocatalyst is highly desired for the photodegradation of dye in wastewater treatment. A series of titanium dioxide nanotube photocatalysts were successfully synthesized using methylamine as N-ligand via hydrothermal treatment at different hydrothermal temperatures and durations. The effect of these two parameters on the photocatalytic activity of synthesized materials were investigated. TEM micrographs and XRD analysis depicted methylamine assisted the transformation of anatase TiO2 nanoparticles to nanotube via the exfoliation of TiO2 crystallite into layered sheet and promoted the curling of layered sheet. Hydrothermal temperature up to 180°C was able to fully transform the morphology of anatase TiO2 nanoparticles into nanotube. The reaction duration was further modified. Fluorescence analysis showed that 24 h hydrothermal duration gave the slowest electron-hole recombination rate. DR-UV-Vis analysis indicated that the synthesized samples were active under UV region. The photocatalytic performance of the synthesized materials was tested in the photodegradation of Congo red under UV irradiation. The results suggested that among the materials synthesized, TiO2 nanotube synthesized at 180°C, under 24 h hydrothermal duration appeared to be the most superior photocatalyst which gave the highest photocatalytic activity of 77%. Possible mechanism of the TiO2 nanotube formation with methylamine as N-ligand is presented.
Preparation of Nanocellulose Bioplastic with a Gradation Color of Red and Yellow
Authors: Nasihin Zulfa Durrotun , Masruri Masruri , Warsito Warsito , Srihardyastutie Arie 
Published: July 2020

Abstract
A bioplastic derived from nanocellulose isolated from the pine flower (Pinus Merkusii) waste has been made. The red and yellow colors of bioplastic were afforded from the extract of dragon fruit and turmeric. Meanwhile, nanocellulose was hydrolyzed by citric acid using concentrations of 10%, 30%, and 60%, and obtained crystallinity index of 61.00%, 57.24%, and 52.82% respectively. Each nanocellulose applied has a crystallite size of 15.09 nm (calculated using XRD data with Scherrer’s equation). The result indicated that the increase in both dragon fruit and turmeric extracts concentration increase the red and yellow color intensity of the bioplastic. This study paves the way for further application of nanocellulose in bioplastic.
Zinc Oxide with Visible Light Photocatalytic Activity Originated from Oxygen Vacancy Defects
Authors: Nimpoeno Wynona A. , Lintang Hendrik O. , Yuliati Leny 
Published: July 2020

Abstract
In this study, ZnO material with oxygen defect was successfully synthesized using a hydrothermal method and interestingly, it was found to possess a remarkable photocatalytic activity under the visible light irradiation. The synthesized ZnO material was then characterized using X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible (DR UV-vis), Fourier transform infrared spectroscopy (FTIR), and spectrofluorometer. Both diffraction pattern and absorption spectrum showed the characteristic of ZnO. However, the maximum emission wavelength of the synthesized ZnO was observed at 558 nm, showing that the ZnO was formed with a high concentration of oxygen vacancy. The excitation spectra also indicated that the prepared ZnO could be excited at the visible light region, which was more than 400 nm. The ZnO was evaluated for photocatalytic phenol degradation under UV and visible light. After 15 hours-reaction, the synthesized ZnO showed the ability to degrade 59.8% phenol under UV light and 39.6% phenol under visible light. This result showed a remarkable performance of ZnO under visible light, which was comparable to that performed under UV light. This study proposed that the existence of oxygen vacancy defects successfully induced the photocatalytic activity of ZnO under visible light irradiation through the electron trapping mechanism in the oxygen vacancy state.
The Effect of Zirconium Addition on Corrosion Behavior of Zn-Zr Alloys as Biodegradable Orthopedic Implant Application
Authors: Pratiwi Rizki Yuni , Trinanda Achmad Fauzi , Ghani Fahmi Moh Waqyan , Astutiningsih Sotya , Zakiyuddin Ahmad 
Published: July 2020

Abstract
In this work, corrosion behaviour of zinc-based alloys with addition of 0.5%, 1%, and 2% of zirconium for biodegradable material as orthopaedic implant were investigated. The potentiodynamic polarization method is carried out to determine the corrosion resistance and corrosion rate of each composition in order to observe the effect of zirconium addition in a Kokubo simulated body fluid solution. The result showed that the addition of 0.5% and 1% of zirconium would decrease the corrosion rate of Zn-xZr alloys corresponding to 0.079 mm/year and 0.116 mm/year whereas the 2% addition would increase the rate to 0.188 mm/year due to the formation of Zr-rich precipitates inside the alloys. The passivation zone on the polarization curve showed the formation of the protected thin layer on the surface of the alloys which caused the corrosion rate to decrease, therefore confirmed the degradable ability of the Zn-xZr alloys. In general, the corrosion rates of Zn-xZr alloys were higher than Fe-based alloys and lower than Mg-based alloys. Moreover, the corrosion rates were much lower than the maximum rate of 0.4 mm/year for biodegradable implants so Zn-xZr alloys were suitable as biodegradable material implant for orthopaedic application.
Natural Dyes Extraction Intended for Coloring Process in Fashion Indutries
Authors: Sutrisna P D , Hadi R P , Valentina J J , Priyantini H R , Waluyo P W , Ronyastra I M 
Published: July 2020

Abstract
Recently, small scale fashion industries are growing quite rapidly in Indonesia. This is due to the continuous encouragement and facilitation by the Government of Indonesia to improve workforce in creative industry. As fashion industries depend on the availability of dyes as one of their resource, it is very important to develop a new and sustainable supply of dyes for dyeing process in fashion industries. Hence, research on the extraction of dyes from sustainable and natural resources for fashion industries are considered very important and urgent. Dyes for fashion and textile are naturally occurred in plants or parts of plants. The extraction of dyes from these sources can be conducted by using simple mixing between solvent and the plants inside a soxhlet extractor or reflux apparatus. In this study, the extraction processes of natural dyes from two materials, i.e. sappanwood, and mango leaf employing combination of maceration, soxhlet and reflux techniques were reported. The experiments were conducted to analyse the effects of extraction time and solvent to materials ratios on the yield of dyes. The experimental results showed that for all materials the optimum ratio of material and solvent was 1 : 6. In addition, the reflux followed by maceration could produce dyes that can be utilised for fabric coloring that suits the industrial needs.
Influence of Activation Time on Ibuprofen Adsorption Using Zinc Oxide from Gelatin Templating Method
Authors: Ulfa Maria , Latifah Umi Wahidatul 
Published: July 2020

Abstract
The present work aimed to investigate the performance of activated zinc oxide for ibuprofen adsorption. The zinc oxide was synthesized by the templating method using F127 and gelatine as a soft template and sulfuric acid as a catalyst. The zinc oxide was activated by an HCl solution 1M for 1, 8, and 24 hours. The raw and activated zinc oxides were characterized by XRD and by infrared spectroscopy. The HCl treatment increases both of the numbers of Zn-O-Zn groups and peak of Zn-O from diffractogram but decreases hydroxyl group content. Ibuprofen adsorption studies of kinetics and isotherms were carried out at room temperature with solid-liquid ratio 3:5(v/v) and water-hexane solution. The adsorption properties were correlated to the activated conditions. The isotherms of adsorption were better reproduced by Langmuir–Freundlich models using activated zinc oxide by HCl at 8 hours. The best performance of ibuprofen adsorption resulted from activated zinc oxide at 8h using water-hexane 1:9 as ibuprofen solvent. The activation time and a high ratio of water-hexane both influence the adsorption of ibuprofen performance.
The Influence of Hollow Cathode Geometry and N2-H2 Gas Mixture on the 2 MHz RF-DC Plasma Species and Density
Authors: Windajanti J M , Abdurrouf  , H Santjojo D J Djoko , Pamungkas M A 
Published: July 2020

Abstract
RF-DC plasma combined with the hollow cathode effect is used to generate plasma inside a hollow cavity. A high-density plasma was formed inside a vacuum chamber using a 2 MHz RF generator. A hollow cathode was utilized to focus the power at the voltage of 150 V with DC bias of -500 V. The plasma system was specially designed for titanium nitriding process at low temperature using N2-H2 gas mixture. The N2-H2 gas with a flow rate of 90-10 mL/minute was conducted at pressure 20 to 150 Pa. The cylindrical and rectangular hollow cathodes are used to make the discharge containing attractive atoms or molecules inside the hollow cavity. The trapped electrons could trigger the secondary electron emission that induced high-density plasma. The geometry components such as gap size, diameter, and cavity depth combined with variations of chamber pressure have been studied to produce high-density plasma. The species inside of N2-H2 plasma were detected by OES based on light emission. The high-intensity peaks of N2
* molecules from the second positive system and N2
+ ions from the first negative system at the wavelength range of 300 to 500 nm were detected to obtain effective plasma species for the nitriding process.
Shell structure of the porous TiNi-framework obtained by the SHS method
Authors: Gunther S , Marchenko E , Baigonakova G , Yasenchuk Y 
Published: July 2020

AbstractPorous SHS-TiNi alloys, presented as a porous framework with a complex structure of the Core-Shell type, were studied by microscopic and structural methods. The core is the porous framework of an intermetallic TiNi phase. The shell was found to be a complex three-layer complex. An oxygen-hardened peritectic TiNi–Ti2Ni layer 1-6 μm thick forms an inner shell layer. Thermo and corrosion-resistant amorphous-nanocrystalline intermetallic oxycarbonitrides, saturated with O, N, C interstitial impurities, form middle and outer layers. The middle dense double layer 60-80 nm thick protects the TiNi matrix. The outer layer 1-15 μm thick has a loose layered structure, it is enriched in the MAX-phases Ti3SiC2, Ti3AlC2. The dense nano double layer provides a chemical passivity to the porous nickelide titanium alloy with shape memory, does not limit mobility and improves the ability to integrate into biological tissues.
Finite Element Modelling of Big Turbo-Generator Rotor Vibrations using Newmark-beta Integration Method
Authors: Kumar Tarun , Kumar Rajeev , Jain S C 
Published: July 2020

Abstract
In this paper big turbo-generator rotor vibrations are simulated for various electrical faults. Newmark-beta method is used to simulate the vibrations at various critical sections of the rotor. Rotor is modelled using finite element method with solid, hollow and tapered elements. Torque in the generator during the course of electrical faults is modelled using dq0 formulation and solved in MATLAB using 4th order predictor-corrector method. Line to ground (L-G), line to line (L-L), three phase (L-L-L) and asynchronization faults are simulated for 300msec. The torsional vibrations in rotor at critical section is found to be most severe during three phase fault followed by mal-synchronization fault followed by the line to line fault followed by line to ground fault.
Biomechanics of fish swimming in a hydrokinetic turbine wake
Authors: Macias M M , Lafuente L , Brasil A C P 
Published: July 2020

Abstract
In the present paper, the assessment of the hydrodynamics of the fish swimming in undisturbed and altered wake-flow is carried out identifying hydrodynamical forces and flow patterns of the fish swimming wake. URANS approach with k-ω/SST turbulence model are employed combining fish and turbine in the same simulation. Fish motion is realized using dynamically adaptive mesh. The actuator line method is employed to induce the wake of a hydrokinetic turbine, which is a simplified method that requires lower computational cost than full geometry simulations. This work brings a new numerical approach involving fish and turbine wake highlighting that fish swimming in the wake presents higher thrust forces than in the undisturbed flow, due to the x-component to velocity in the wake is lower than free flow velocity.
Comparison of experimental and model liquid distribution in large packed bed of Raflux rings 50-5
Authors: Petrova Tatyana S , Dzhonova-Atanasova Daniela B , Semkov Krum A 
Published: July 2020

Abstract
This work presents a continuation of our investigations on the radial liquid distribution in packed beds with open-structure random packings, by means of a dispersion model, in a scale, close to industrial one. Using experimental data for uniform initial irrigation, the optimal parameters’ values of the three parameters of the dispersion model are obtained by two-parameter identification. One of the parameters (the radial spreading coefficient) is calculated independently by using experimental data for a point source initial irrigation. The dispersion model solution at optimal parameters’ values is compared with both experimental and TUM WelChemCell model literature data for the liquid radial distribution in a packed column with a diameter of 1.2 m and random packing Raflux rings 50-5. The maldistribution factor of the liquid distribution is also calculated and compared. The comparison shows very good agreement between our results and the literature data and confirms the dispersion model capability to predict the liquid distribution in large columns with open-structure packings.
Rate-dependent viscoelasticity of an impact-hardening polymer under oscillatory shear
Authors: Xu Yangguang , Lubineau Gilles , Liao Guojiang , He Qianyun , Xing Tao 
Published: July 2020

Abstract
The rate-dependent effect of viscoelasticity plays a critical role in the hardening mechanisms of impact-hardening polymers (IHP) when forcefully impacted. In this study, we used dynamic mechanical analysis (DMA) to characterize the rate-dependent viscoelasticity of an IHP under oscillatory shear. We found that the storage modulus increased by three orders of magnitude within the experimental range when the oscillatory frequency varied from 0.1 to 100 rad/s. To further understand the real strain rate effect of IHP, we introduced the Havriliak-Negami (H–N) model to predict the dynamic viscoelastic behaviors of the IHP for a wider frequency range (from zero to infinity) than that applied in the DMA experiments. Based on the H–N model results, we defined a parameter to describe the rate-dependent effect of the IHP, which was not dependent on the frequency range and reflected the intrinsic material properties of IHP. We used the time-temperature superposition principle (TTSP), which extended the experimental range from 0.1 rad s−1 down to 0.005 rad s−1, to verify the accuracy of the rate-dependent viscoelasticity predicted by the H–N model. Finally, we outlined the influence of temperature on the dynamic viscoelastic behaviors of IHP and discussed the phase transition mechanism induced by temperature and the oscillatory frequency. The results presented here not only provide a method (i.e., by combining experimental results with the H–N model results) to characterize the real rate-dependent viscoelasticity of IHP but are also valuable to further our understanding of the impact-hardening mechanisms of IHP.