bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and Properties of Phase Change Material by Microencapsulation of Lauric Acid for Thermal Regulation
Authors: Gecain M K , De Leon R L
Published: May 2020

Lauric acid, the phase change material (PCM) in this study, is encapsulated in a silica shell using a modified sol-gel method. Encapsulation was done at varying pH, mixing ratio, drying temperature and drying time. Analysis of variance revealed that all these parameters and their interactions affect the PCM yield and encapsulation ratio. FT-IR and DSC Analysis showed that the microencapsulated PCM (μPCM) formed using 1:1:2 mixing ratio of Tetraethyl orthosilicate: Ethanol: Water, with pH ∼1.92 and drying condition of 100°C for 7hr had a latent heat of fusion (207.65 J/g) similar to that of pure PCM with latent heat of fusion of 212.47 J/g ). SEM Analysis and DSC were utilized to confirm the efficiency of encapsulation of PCM. The glass sheet with μPCM and binder was found to have a latent heat of 182.14 J/g and a thermal conductivity of 0.0537 W/mK. The glass with silica microencapsulated lauric acid exhibited potential application for energy conservation.
Synthesis and Modification of Metal Nanoparticles by Plasma over an Aqueous Solution under Pressurized Argon
Authors: Wahyudiono  , Kondo Hiroki , Yamada Motoki , Takada Noriharu , Machmudah Siti , Kanda Hideki , Goto Motonobu
Published: May 2020

Metal−based nanoparticles have been used in diverse industrial applications owing to their physicochemical properties. Here, the electric field produced by pulsed high−voltage discharge plasma over an aqueous solution surface that was generated under high−pressure argon environment would be employed to synthesis and to modify metal materials. The plasma reactor was made of stainless steel and contained two sapphire windows to monitor the plasma performance. The experiments were conducted at room temperature (25 − 28 °C) with argon environment at a pressure of 3.0 MPa and the DC power supply at 18.6 kV was introduced into the reactor through the electrode to generate pulse electrical discharge plasma. The metal rod electrode which was used as a material source for nanoparticles generation was placed over an aqueous solution containing glycine, as carbon source, to introduce electrical discharge plasma. The scanning transmission electron microscopy which was equipped with energy dispersion spectroscopy (STEM coupled with EDS) indicated that titanium dioxide and iron oxide with and without carbon covered were successfully produced in nano−scale (<100 nm).
MnO2 Nanoparticles Prepared by Alternating Monopolar Arrangement Electrolysis and Their Electrochemical Performances
Authors: Widiyastuti  , Setyawan Heru , Rois Mahardika F. , Purwaningsih Hariyati , Nurlilasari Puspita
Published: May 2020

Manganese dioxide nanoparticles have been successfully synthesized by the electrolysis method using 4-pairs carbon electrode in the alternating monopolar arrangement. The advantage of the arrangement is a significant increase in the product yield compared to the single pair electrodes. KMnO4 solution in pH 0.2 and 9 were used as precursor and electrolyzed for thirty minutes at a temperature of 60 °C. The generated particles resulted from electrolysis in pH 0.2 (MnO2-A) and in pH 9 (MnO2-B) were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), and nitrogen adsorption-desorption isotherms to examine their crystallinity, morphology, and the specific surface area. The α-MnO2 was observed for MnO2-A particles and amorphous for MnO2-B particles. The particles size of MnO2-A was larger than that of MnO2-B with the specific surface areas of 396 and 98 m2/g, respectively. The higher surface area of MnO2-A corresponding to the channel pore of short rod-like morphology. On the other hand, MnO2-B contributed to the spherical particles. The measurements of cyclic voltammetry (CV) were also carried out to measure their specific capacitances and their performance for oxygen reduction reaction (ORR) electrocatalyst. MnO2-A exhibited higher specific capacitance of 13.57 F/g compared to MnO2-B that only had 3.62 F/g. In addition, MnO2-A also gave better performance as ORR electrocatalyst measured in O2-saturated 0.6 M KOH resulted in 2.69 transferred electron number per oxygen molecule.
Unravelling the Swelling Behaviour and Antibacterial Activity of Palm Cellulose Nanofiber-based Metallic Nanocomposites
Authors: Supramaniam Janarthanan , Kiat Wong See , Fen Leo Bey , Teng Hern Tan Loh , Hing Goh Bey , Ying Tang Siah
Published: May 2020

The development of functional antimicrobial metal oxide nanocomposite systems based on nanocellulose has been the subject of extensive research in recent years. In addition to its sustainability, biodegradability and non-toxic properties, nanocelullose present an extremely high surface area favoring the selective growth and immobilization of ultrafine metal oxide nanoparticles on the cellulosic surface. In this study, oil palm biomass-derived cellulose nanofiber (CNF) decorated with zinc oxide (ZnO) nanocomposites were produced via ultrasound-assisted in situ co-precipitation approach. The morphology and chemical composition of the as-synthesized ZnO/CNF composites were characterized using field emission scanning electron microscopy (FE-SEM) and Fourier-transform infrared (FT-IR). FE-SEM images revealed the fibrous morphology of nanocomposites with a good distribution of ZnO NPs. The FT-IR analysis confirmed a strong interaction between surface functional groups of CNF and ZnO nanoparticles. The swelling behavior of composites was found to be improved with addition of ZnO nanoparticles in the CNF matrix. The hybrid ZnO-CNF exhibited pronounced antibacterial properties against methicillin-resistant Staphylococcus aureus (MRSA). The findings of present study support the possibility of using this palm CNF-based metallic nanocomposites as nanofillers for wound care application.
Synthesis and Characterization of Fe3O4 Nanoparticles Using Different Experimental Methods
Authors: Mahmud Nafis , Nasser Mustafa S. , El-Naas Muftah H. , Ba-Abbad Muneer M. , Wahab Mohammad Abdul , Mansour Said , Benamor Abdelbaki
Published: May 2020

This paper reports a comparative study on the synthesis of Fe3O4 nanoparticles using three different methods, namely; Co-precipitation, Sonochemical and Solvothermal methods. Ferric chloride hexahydrate (FeCl3.6H2O) and Ferrous chloride tetrahydrate (FeCl2.4H2O) were used as the iron precursor for the Co-precipitation method; while, Ferrous sulphate Heptahydrate (FeCl2.7H2O) and Ferric chloride hexahydrate (FeCl3.6H2O) were used as the iron precursor for sonochemical and solvothermal synthesis methods, respectively. The effect of the experimental methods and the precursors used on the shape and size of the Fe3O4 nanoparticles were investigated using different characterization techniques. The chemical characterization of the samples were carried out using EDX. The size of the nanoparticles were determined using particle size analyzer. The SEM and TEM images were used study to the surface morphology of the produced nanoparticles. Finally, TGA was used to study the thermal stability of the prepared iron oxide nanoparticles.
The Numerical Estimation of Mass Transfer Coefficient of Oxygen in the Large-Scale Suspension Culture of iPS Cells
Authors: Isobe R , Kanemaru Y , Sekimoto A , Okano Y , Kino-Oka M
Published: May 2020

In order to practically apply induced pluripotent stem (iPS) cells to regenerative medicine, a large amount of undifferentiated iPS cells should be produced by using an automated/scaled-up suspension culture system. However, in large-scale culture, oxygen supply to iPS cells away from the gas-liquid interface can be insufficient. In this numerical study, the oxygen supply performance is quantitatively evaluated by estimating the volumetric mass transfer coefficient of oxygen in the suspension culture of iPS cells. And, focusing on shaking culture, where shear stress that causes death or differentiation of iPS cells is relatively reduced, we compare two different shaking methods: one direction rotation (ODR) and periodic alternate rotation (PAR). The validity of the volumetric mass transfer coefficient calculation is confirmed by comparison with the experiment. The PAR method is superior to the ODR method in terms of oxygen supply because of higher turbulence intensities, but it is much less energy efficient than the ODR method. In the ODR method, the cell size is thought to be non-uniform since iPS cells are aggregated due to cell sedimentation. On the other hand, in the PAR method, cell sedimentation is suppressed by controlling the Froude number (Fr).
Biopolymeric encapsulation of probiotics for improved release properties in the gastrointestinal digestion system
Authors: Mohammad N A , Zaidel D N A , Muhamad I I , Hamid M A , Yaakob H , Jusoh Y M M
Published: May 2020

Encapsulation of probiotics in the biopolymeric system is an excellent technique to enhance the protective effect, prolong the shelf life and deliver the probiotics in the human gastrointestinal tract at a specific time. Probiotics are usually loaded in a biopolymeric system or the food itself as a natural carrier for food applications. Probiotics are well-known for a healthy intestinal tract and digestibility of nutrients. The fate and viability of these bacteria in the digestion system are explored through in vitro evaluations. Probiotics encapsulated with natural biopolymers such as alginate, chitosan, gelatine, whey protein are found to improve their release properties in either emulsion or hydrogel system. This review emphasized on the release properties of encapsulated probiotics loaded with biopolymers using different dispersion methods including emulsification, suspension, extrusion, and drying. Biodegradable polymers or the food itself could be a potential protective agent and promote the controlled-release properties of probiotics.
Characterization of chitosan from extracted fungal biomass for piezoelectric application
Authors: Ahmad F. B. , Maziati Akmal M. H. , Amran A. , Hasni M. H.
Published: May 2020

Conventional piezoelectric materials from piezoceramic and polymer are non-renewable and could be toxic in nature, which limit its application in biomedical application. Chitosan, which is a natural polysaccharide, has the potential to be used as piezoelectric biomaterial which may provide the solution for toxicity, non-biodegradability and non-biocompatibility issues of conventional piezoelectric materials. Chitosan may be produced sustainably through extraction from fungal cell walls. This study aims to characterize chitosan extracted from fungi Aspergillus oryzae for piezoelectric application. A. oryzae was cultivated on modified Sabouraud dextrose broth medium. Alkaline treatment was performed on fungal biomass using 1 M NaOH for extraction and deacetylation of chitosan at 100 °C for 1 hour. Fourier transform infrared spectroscopy results showed that the broad absorption band that corresponds to hydrogen bonded O-H stretching vibrations overlapped with N-H stretching band. X-ray diffraction analysis confirmed the semicrystalline nature of the chitosan sample. Piezoelectric properties can be attributed to intrinsic molecular polarization arising from the noncentrosymmetric crystal structure.
Determination of Diffusion Coefficients and Antioxidant Activities of Ascorbic Acid in Guava Juice using Cyclic Voltammetry
Authors: Ang K. B. A. , Lee C. M. , Yu H. M. O. , Uy M. , Soriano A. N. , Dugos N. P.
Published: May 2020

Ascorbic acid is the most abundant antioxidant present in guava (PsidiumguajavaL.). There had only been few studies concerning the determination of diffusion coefficient and antioxidant activity of ascorbic acid in guava juice using cyclic voltammetry specifically at varying temperatures. Thus, this study on the effect of temperature on diffusion coefficient and antioxidant activity on ascorbic acid found in guava was done using cyclic voltammetry. The temperatures tested were at 15°C, 25°C, 36°C, and 45°C. Electrodes used in the experiment were glassy carbon as the working electrode, platinum wire as the counter electrode, and Ag/AgCl electrode as the reference electrode. The results showed that the peak currents of ascorbic acid in guava juice at 15°C, 25°C, 36°C, and 45°C were -0.5720, -0.5380, -0.5000, and -0.4760 μA, respectively. The diffusion coefficients of the ascorbic acid were obtained using the Randles-Sevcik equation at all given temperatures and the values were 2.1489 x10−5, 2.1711 x10−5, 2.2070 x10−5, and 2.2250 x10−5cm2/s, respectively. The antioxidant activities, in terms of concentration, at the said temperatures were found to be 0.3374, 0.3212, 0.3015, and 0.2899 mM, respectively. It is concluded that at higher temperature, ascorbic acid in guava juice has a higher diffusion coefficient but lower antioxidant activity. The present results can be used by other researchers doing similar work on fate and transport of the studied system.
Bioethanol production from microalgae Chlorella sorokiniana via simultaneous saccharification and fermentation
Authors: Tatel N J , Madrazo C
Published: May 2020

This study aimed to investigate the performance of a microalgal feedstock Chlorella sorokiniana in bioethanol production through simultaneous saccharification and fermentation (SSF). The major limiting factor of SSF is the compensation between optimum hydrolysis and fermentation parameters. Using a central composite design (CCD), three parameters were optimized: biomass concentration, temperature, and pH. For each run, the enzyme mixture (cellulase and amylase) was fixed at 25 g/L, fermentation time at 72 hrs, and inoculum size of Saccharomyces cerevisiae at 20% (v/v). The freeze-dried biomass is simultaneously mixed with the enzyme mixture and the inoculum and placed inside an incubator shaker. The microalgal biomass is found to contain 58.78% total reducing sugars (TRS). Highest ethanol yield obtained is 0.504 g ethanol/g glucose. Using CCD helps navigate the design space and bioprocess.
Evaluation of different carbonate sources for bicarbonate-based integrated carbon capture and algae production system using Spirulina platensis
Authors: Batac C C , Gathercole N S , Maravilla A F , Beltran A B
Published: May 2020

Spirulina Platensis was evaluated in Bicarbonate-based Integrated Carbon Capture and Algae Production System (BICCAPS) using Modified Zarrouk’s media under three different carbonate solutions, namely, sodium, potassium and an equimolar mixture of sodium-potassium carbonate, as well as a control experiment consisting of only water. All systems mentioned were exposed to carbon dioxide loading in order to produce bicarbonate solutions to be used for cultivation of Spirulina Platensis under BICCAPS. Parameters such as pH, biomass productivity, and carbon conversion were analyzed to evaluate the effectivity of BICCAPS as a carbon sequestration technique given the conditions applied in the study. Results determined that the control system produced the highest biomass productivity of 10.42 mg L−1 day−1 despite having the lowest carbon conversion of 0.292 mM due to the limited amount of bicarbonates initially present. The sodium-potassium carbonate system then follows the control experiment, having a productivity of 7.37 mg L−1 day−1 and carbon conversion of 4.192 mM. Sodium carbonate system ranks third with productivity and carbon conversion of 6.56 mg L−1 day−1 and 2.682 mM. Lastly, potassium carbonate system was determined to have the lowest productivity of 4.48 mg −1 day−1 as well as a relatively low carbon conversion of 0.996 mM.
Role of Operator Training Simulator (OTS) in Capability Building towards the Fourth Industrial Revolution (IR 4.0)
Authors: Hasnor Hassaruddin Hashim A. , Noorhidayah Hussein B.
Published: May 2020

The manufacturing industry is now shifting towards Industrial Revolution 4.0 (IR 4.0), in which digitization of manufacturing industry has led the industry towards autonomous system driven by big data as well as machine learning. Despite shifting towards fully automated systems, human intervention is required every now and then especially during unforeseen circumstances. Hence the capability building of the plant personnel as well as technical specialist is inevitable, especially when related to plant safety. The use of Operator Training Simulator (OTS) has been in the industry for quite some time for plant personnel capability development. OTS is a system which combines chemical engineering design and knowledge (embedded in a dynamics simulation model) and process control and safety instrumented system (embedded in Distributed Control System (DCS) database), which can be used for plant personnel’s capability development which serves as the Digital Plant. The usage of OTS system is a new way of learning with the realistic feeling of operating the real plant via the Digital Plant without endangering the plant and personnel. By using OTS system, the plant personnel will be able to understand the process control system installed in the plant as well as process interaction between units in the plant since the Digital Plant was developed as close as the real plant to provide the near-real operation experiences. The OTS system is equipped with many functionalities such as malfunction tests, scenario tests, etc. to assess the plant personnel capability in handling unforeseen circumstances such as critical equipment failures and abnormal plant operation. The system also provides capability assessment for each personnel involves in the training which can be used to evaluate the personnel technical and operating capability, and to re-evaluate the steps taken during the training to improve teaching and learning approaches. By integrating chemical engineering knowledge, plant safety instrumented system and capability development program, OTS system will be able to bring capability development program towards achieving safe and reliable IR 4.0. implementation.
Recovery of Gold from Pregnant Thiourea Leaching Solution by Synergistic Extraction
Authors: Jumain Jalil Mohd , Halimi Mohd Azam Zaki Haris , Suhada Azmi Intan , Aminuddin Ahmad Zulkifli Ariff , Hazim Abu Bakar Muhammad , Bin Mohd Rashid Anas
Published: May 2020

Aim of this research is to investigate the ability of synergist system of D2EHPA-isodecanol to recover gold from thiourea leaching solution. Synergistic extraction was introduced to replace single extraction due to enhance the extraction efficiency of heavy metal such as gold, silver copper and etc. In order to improve extraction efficiency, di-(2ethylhexyl) phosphoric acid (D2EHPA) was mixed with isodecanol to provide synergistic effect together with leaching solution which thiourea. From the synergist extraction system. The optimum pH is at 2.5 which in acidic range producing the highest yield of %E of 94.6%. It was found that synergistic D2EHPA-isodecanol extraction is successful as it yield %E of 99.4% if the ratio aqueous: organic is set to 1:2.
Overcome the equilibrium limitation in para-Xylene production by using reactive distillation method
Authors: Phu Nguyen Quy , Trung Nguyen Kim , Anh Nguyen Tuan , Tetsuo Fuchino
Published: May 2020

To overcome the equilibrium limitation of liquid phase-Xylene isomerization in maximum para-Xylene (PX) yield at 24% molar is a significant objective in either academics or industrial application, regarding the importance of PX in various polyester productions. In this study, integration of reaction and extractive distillation into a reactive distillation column (RDC) is proposed as a solution for the enhancement of PX yield. The desired product is simultaneously generated and purified in the only equipment so the conversion could be forward shifted to overcome equilibrium limitation in Xylene isomerization. Obstacles relating to the close boiling points of xylenes are alleviated by an inert solvent introduced into the system to facilitate the separation of xylene isomers. The flowsheet which is configured by a reactive distillation column and a recovery column manifests advantages of the method for para-Xylene production. The highest PX yield can be obtained up to 37% molar, while other cases result in the yield of p-Xylene higher than 25% molar. The effect of design parameters, including the number of stages in reactive-, rectifying- and stripping sections on process performance, is carefully examined to study the behavior of the RDC and system.
Pseudo-homogeneous Kinetic Evaluation for in-situ Epoxidation of Oleic Acid
Authors: Retno Sawitri Dyah , Mulyono Panut , Rochmadi  , Budiman Arief
Published: May 2020

Epoxidation of unsaturated fatty materials is useful route to synthesize valuable material especially bio-based polymers. Oleic acid (OA, iodine value of 90 gram I2/100 gram) is the most common unsaturated fatty material that can be found in vegetable oils or animal fats. Epoxidation of oleic acid with peracetic acid generated in-situ has been performed in batch system. Kinetic evaluation was conducted by varying the reaction temperature from 40 to 70 °C under constant value of stirring speed, H2O2:OA molar ratio, acetic acid:OA molar ratio, and catalyst concentration. Double bond conversion, oxirane yield, and selectivity of oxirane has been evaluated. The result shows that the degree of side reaction (ie: ring opening) is high in temperature of 60 and 70 °C. Pseudo-homogeneous kinetic model is well fitted in 40 and 50 °C but it gives significant deviation in 60 and 70 °C. The activation energy of oleic acid epoxidation has been found to be 62.2 kJ/mol.
Exsolution of nickel alloys anchored nanoparticles on perovskite oxides for CO oxidation
Authors: Wan Ramli W K , Papaioannou E , Naegu D , Metcalfe I S
Published: May 2020

Noble metals notably platinum (Pt), is a major element of heterogeneous catalysts, excel in catalysing an extensive number of important catalytic reactions in chemical and automotive industries. Since the increased use of these metals is severely limited because of their high cost and scarcity’s, there is therefore an urgent need for the search of alternative transition metal catalysts that are cheaper and more widely available. This can only be practical if the main drawbacks of these transition metals can be impeded for instance the agglomeration of particles under high temperatures operational conditions with their activity enhanced, such that they can directly replace Pt on a weight-to-weight basis. The exsolution of metallic nanoparticles mainly nickel (Ni) at the surface of perovskite oxides in situ has shown remarkable catalytic activity and durability towards carbon monoxide (CO) and nitric oxide (NO) oxidation and in fuel cells. In this study, for CO oxidation reaction, the catalytic capabilities of exsolved Ni nanoparticles can be further enhanced when iron (Fe) and cobalt (Co) are co-exsolved with Ni, as FeNi and CoNi alloy nanoparticles, forming mixed oxide nanoparticles. FeNi alloy nanoparticles exhibit almost ten times site activities as compared to the Ni nanoparticles, owing to the oxide layer formation which then aided the oxidation of CO. Interesting enough, the CoNi alloy nanoparticles exhibit slightly different morphological and chemical transformation due to the difference in oxidation mechanism and the degree of oxidation, which reveal greater site activities towards CO oxidation. These nanoparticles were also subjected to additional compressive strain when they expanded as a result of them being pinned to the support. These results pave the way for new approach in altering the activity of the exsolved materials for various reactions.
A facile synthesis of CuCe and CuCeFe mixed-oxide catalysts by solution combustion method for catalytic methane combustion
Authors: Kruemek P , Mattathankul S , Triamnak N , Chotigkrai N
Published: May 2020

In this research, the solution combustion method was used to synthesize non-noble catalysts including copper-cerium (CuCe) and copper-cerium-iron (CuCeFe) mixed-oxides for catalytic combustion of methane. The effects of Cu contents (5, 10 and 15 wt%) and Fe addition were investigated. The synthesized catalysts were characterized by XRD, N2-physisorption, and H2-TPR. The results showed that increasing Cu content exceeds 10 wt% for a series of CuCe catalyst, leading to a collapse textural structure and formation of larger CuO phase. It resulted in the substantial drop of the catalytic activity for methane combustion. Furthermore, incorporation of Fe into Cu-Ce mixed oxides causes the formation of Fe2O3 and Ce-Fe-O solid solution, stabilizing the textural properties, enhancing the oxygen vacancies and oxygen mobility. The superior catalyst was 15CuCeFe because it revealed the highest methane conversion at 500 °C and relatively high conversion at a lower temperature. It can be seen that solution combustion is a facile method to prepare the mixed-oxide catalysts and incorporating the metal promoters. The Cu, Ce and Fe metals play a significant role in catalytic methane combustion not only enhancing reactants (methane and oxygen) activation but also improving the physical properties.
Use of metal mesh to assist the multi-phase reaction in a microreactor
Authors: Charoenpong P , Pavarajarn V
Published: May 2020

Glycerol is a by-product from biodiesel production. Glycerol can be further converted to glycerol carbonate by several reaction routes. One of the feasible routes that have been generally reported is the reaction between glycerol and urea, while ammonia gas is generated as one of byproducts. The reaction generally requires a heterogeneous catalyst, which causes mass transfer problem. Most researchers have applied this reaction in batch, continuous-stirred tank, or fixed bed reactors, in which the external mass transfer resistance is still dominant. Due to many advantages of microreactor including high surface area-to-volume ratio, short diffusion distance, small mass and heat transfer resistances, applying the microreactor can solve the problems and enhance the reaction, Therefore, in this work, microreactor was utilized in the production of glycerol carbonate from glycerol and urea, which one side of microchannel wall was coated by commercial catalyst. In addition, Metal mesh sheet with pores is used to separate ammonia gas from the reaction. This research studies the effect of residence time, microchannel thickness, shear stress of reactants and a quantity of generated gas on a catalyst slipping, and also investigates the effect of metal mesh size on yield of glycerol carbonate from reaction in microreactor.
Kinetic study on the pyrolysis of low-density polyethylene (LDPE) waste using kaolin as catalyst
Authors: Erawati Emi , Hamid  , Martenda Danik
Published: May 2020

The increase in the industrial and urban activities has resulted in the rise of plastic production and consumption. The higher demand for plastic causes accumulation of plastic waste in which it contributes to environmental problems. About 65-70% of plastic waste is a type of Low-Density Polyethylene (LDPE). To reduce this type of waste, the pyrolysis method can be an alternative. This study investigated the catalyst ratio and particle size of the material. The results indicate that the optimum catalyst was at 15% wt/wt with liquid and gas yields of 99.15% and 0.85%, respectively. Meanwhile, the optimum particle size variation is at 7.5 x 6.5 cm with liquid and gas yields of 99.82% and gas 0.18%, respectively. The proximate analysis of LDPE wastes includes the analysis of ash content, volatile matter, and fixed carbon, with the values of 0.35, 99.61 and 0.04% wt/wt, respectively. The chemical composition is analyzed using Shimadzu GCMS-QP2010S. The highest percentage component is heptane. The fuel analysis shows pyrolysis oil products comply with the national standard set by the regulation No. 14499 KJ14/DJM/2008. The reaction kinetics parameters of the liquid and gas activation energy are of 127,025.79 J/mol and 73,766.93 J/mol, respectively. Meanwhile, the liquid and gas pre-exponential factors are 8,590 and 257,respectively.
Offset-free control of a pH system using Multiple Model Predictive Control
Authors: Hermansson A W , Syafiie S
Published: May 2020

In this paper, a novel combination of a multi-model predictive controller (MMPC) and an adaptive integral controller is usedto achieve offset-free control of a nonlinear process. The idea is to avoid the more complex tuning that comes with an offset-free control based on an observer. To create an easily tuned controller based on a piecewise linear (PWL) description of an MPC setup, which utilizes a Bayesian weighting approach. The PWL models are also used to design the separate the I-controller that is made adaptive by using the Bayesian weighting again. The MPC and the I-controller are then acting in parallel. The setup is implemented and tested using a simulation of a pH neutralization process.
Optimization and Analyzing of Subcritical Organic Rankine Cycle Using R1234ze(E) for Low and Medium Temperature Heat Source
Authors: Rowshanaie O , Tohir M Z M , Mustapha F , Ya’acob M E , Rowshanaie H
Published: May 2020

A model of Subcritical Organic Rankine Cycle (SORC) driven by trans-1, 3, 3, 3-tetrafluoroprop-1-ene, R1234ze(E) as a new-typed environmental friendly refrigerant working fluid, was developed and analyzed in the view of the 180-220°C wet fluegas combustion and burning from natural gas, as a low to medium temperature heat source without the outlet temperature limit to generate optimum power by a turbine. The net power output, total efficiency, fluegas outlet temperature, and exergy efficiency of current SORC system were studied based on variation of vapor generator outlet temperature and turbine outlet pressure as optimized parameters in terms of per mass flow rates of working fluid, heat source, and heat sink. Results show that the maximum net power output is 5.2675 MW and with increasing of mass enthalpy change and temperature in expansion process causes to increase of net power output, steadily. And the maximum net power output was 53.1% increased. Furthermore, by decreasing the turbine outlet pressure, the total efficiency of the current SORC system is increased to 0.08107 because of the increase of net power output. Likewise, the exergy efficiency of the SORC system increasing significantly, and received to the 0.328, because of increasing the enthalpy change and decreasing the entropy change of fluegas in the evaporator system.
Probabilistic assessment of off-the-shelf fire sprinkler Head activation time through laboratory experiments
Authors: Tajudin M A S , Tohir M Z M , Said M S M
Published: May 2020

The activation time of a sprinkler has a great impact on the fire growth inside a compartment. The longer time it takes for a sprinkler to activate, the higher the risk of fire to start to spread inside the compartment. In this study, the activation times of off-the-shelf half inch 68°C fire rated pendant sprinklers were assessed through experiments in laboratory settings and eventually best-fit probabilistic curve for the Response Time Index (RTI) were generated from the experimental results. The experiments were conducted in two sets; one set without smoke effect and the other set with smoke effect to determine the activation time and temperature of the sprinkler heads. The data recorded were then used to calculate the RTI and Palisade @ RISK statistical analysis software was used to analyze the best-fit probabilistic curve for the RTIs. It was observed that, average time required for sprinkler to activate was 60 seconds. It was also found that the calculated RTI were within the range of the international sprinkler design guideline. However, the calculated RTI were found to be inconsistent with specified RTI from manufacturer. Based on @ RISK software, the two best-fit RTI probabilistic curve for the two experiments were Gamma and BetaGeneral distribution curve. The probabilistic curves obtained from this work can be used as input for fire in enclosure simulations.
Numerical Simulation of the Drying Kinetics of Sweet Potato to Prevent the Growth of the Fungi Rhizopus oryzae
Authors: Obregon F I V , Silvano M B C , Vicencio J G , Pestaño L D B
Published: May 2020

Sweet potatoes are prone to fungi Rhizopus oryzae that results in fast spoilage upon delivery due to its moisture content which can develop fungi that can give foul odor and color. The decrease in moisture content can prolong the shelf-life of the sweet potato. This problem can be addressed by a drying process where a hot tray air dryer was used. Sweet potatoes were cut to 5x5x30 mm uniformly and dried it at 40°C, 50°C, 60°C until the constant weight of the batch was obtained. Laplace Transform Model, Non-Linear Decomposition Model, and Page Model are the three mathematical model that were compared to determine what is the best fit for the drying of the sweet potato. Based on data gathered, Page Model is the best fit at 60˚C. Page Model fitted best from the other two models with an average drying time of 115 minutes and 46 mins to obtain the desired moisture content of 10%.
Modeling and optimization of pilot-scale subcritical water extraction on Zingiber zerumbet by central composite design
Authors: Nur Khairunisa Mohd Amir Siti , Firdhaus Mad Nordin Mariam , Shameli Kamyar , Mohamad Abdul Wahab Izzati , Abdul Hamid Mariani
Published: May 2020

Zingiber zerumbet (Z. zerumbet) or locally called ‘lempoyang’ is one of the ginger species extensively cultivated and utilized in the Southeast Asia region. In order to extract valuable ingredients from Z. zerumbet, a green and non-toxic extraction process is implemented namely subcritical water extraction (SWE). Modeling and optimization of SWE of Z. zerumbet are performed using the central composite design (CCD) by 20 runs with 6 repetitions at the center point. The independent variables investigated in this research are temperature (130-170°C), time of extraction (20-40 minutes) and solid to solvent ratio (20-40 ml/g) that focused to identify the optimized process parameters for zerumbone concentration, antioxidant activity, and yield of extracts. All independent variables researched were analyzed to be significant as the p-value for zerumbone concentration, antioxidant activity and yield are 0.0001, which are less than 0.05 for a model to be significant. The optimum process parameters for all responses of Z. zerumbet extract are at 170°C, 20 minutes and 20 ml/g. This optimum condition was validated and the correlation between predicted and experimental values was within 95% which indicated the range of variables selected was valid. Thus, the outcome from this research may be beneficial on subcritical water extraction of ginger species especially Z. zerumbet.
Parametric and optimization studies on the production of nanoscale biochar-NPK fertilizer using sugarcane bagasse-derived biochar as carrier
Authors: Chiam Paulo C. , Concepcion-Maguyon Detras Monet , Migo Veronica P. , Alfafara Catalino G.
Published: May 2020

Current agricultural practices such as excessive and inefficient application of conventional fertilizers causes serious environmental problems. Thus, this study aimed to produce a fertilizer with nitrogen, phosphorous, and potassium impregnated in an activated sugarcane bagasse biochar which has potential for slow nutrient release. Activated sugarcane bagasse-derived biochar was produced via pyrolysis at 450 °C for 1 hour followed by activation using potassium hydroxide. Analysis of the activated biochar showed that it has a high capacity to hold exchangeable cations with a value of 127 mol c/kg soil, high porosity and large surface area (79 m2/g), and high carbon content (77.3% wt). The effects of biochar-NPK ratio (w/w), mixing time, and mixing temperature on the nutrient content of the fertilizer were then evaluated implementing a full factorial experimental design. All main factors were found to be significant on the NPK content of the fertilizer. Optimization runs were subsequently done following Response Surface via Central Composite Design (CCD) to determine formulation conditions for maximum NPK content of the fertilizer. Optimized conditions were 1:2 (w/w) biochar-NPK ratio, 50 °C mixing temperature, and 25.60 minutes mixing time. The nitrogen, phosphorous, and potassium content of the fertilizer at optimum condition were successfully verified to be 4.20 %N, 7.57 %P, and 7.01 %K, respectively. The average particle size of the fertilizer was found to be about 2117.2 nm with a polydispersity index of 0.568. The properties of the biochar-NPK fertilizer may be further examined to evaluate its capacity for controlled- or slow-release of nutrients.
Fouling Detection in Heat Exchangers using Extended Kalman Filter
Authors: Muenthong S. , Chattakarn S. , Lersbamrungsuk V.
Published: May 2020

Heat exchangers are important equipment widely used in industries for heat transfer. However, after a long operation, the efficiency of heat transfer may be reduced due to the deposition of impurities on the heat transfer surface, called, fouling. In practice, detection of fouling in heat exchangers is needed for diagnostic, monitoring, and maintenance purposes. This research proposes a fouling detection method using Extended Kalman Filter. Heat exchangers are simulated using cell-based model. Asymptotic fouling model is considered. In detection of fouling in heat exchangers, overall heat transfer coefficient will be estimated using Extended Kalman Filter. The required information in Extended Kalman Filter includes measurement of outlet temperatures on hot and cold sides and heat exchanger models. The results show that for perfect model case, i.e., using same model in simulated heat exchanger and Extended Kalman Filter, overall heat transfer coefficient can be properly estimated. However, for model mismatch case, an offset in estimation can be observed. Although there is an existence of offset in estimation, Extended Kalman Filter can predict the trend of change in heat transfer coefficient quite well.
Electrospinning of PLA with DMF: Effect of polymer concentration on the bead diameter of the electrospun fibre
Authors: Amirah Md Zubir Ainaa , Khairunnisa M P , Atiqah Surib Nur , NorRuwaida J , Halim bin Md Ali Abd , Rashid M
Published: May 2020

Electrospinning has been known for its’ ability in producing nanoporous fibres which uses electrical force to form a spinning jet out of a polymer solution. The electrospinning condition and polymer solution properties can influence the electrospinning jet formation as well as jet path. Polylactic acid (PLA) was dissolved in dimethylformamide (DMF) to produce a polymer solution. Bead is considered as a defect towards an electrospun fibres, yet previous study found that PLA/DMF produced beaded fibres for all concentrations. However, there is a limited study that explain the effect of concentration on the diameter of beads. Therefore, in this study we investigated the formation of electrospinning jet as well as the effect of PLA concentration of formation of beads, particularly the diameter of the beads. Polymer solution with different concentration was prepared. The concentration investigated in this study were 7.5, 10, 12.5, 15, 17.5, and 20 % w/v. Polymer solution was then subjected to the electrospinning process to evaluate the morphology of the electrospun produced via optical microscope. Simultaneously, the formation of electrospinning jet is observed with portable digital microscope. The morphology of the electrospun fibres, especially the fibre and bead diameter are analyzed using image analysis software, ImageJ. From this research, it is found that at voltage of 10 and 12.8 kV, a stable electrospinning jet can be formed which consists of ‘Taylor cone’, straight jet, and plume. Concentration from 7.5–20 % w/v were able to form electrospun fibres, yet only 12.5 and 15 % w/v PLA concentrations can produce an effective electrospun fibres with beads diameter of 3393 nm and 3642 nm, respectively. Also, the number of beads for both concentrations are 34 and 19, respectively. Since the main criteria in producing electrospun fibres is no beads or small and minimal beads at best, therefore 12.5 and 15 % w/v PLA concentration are considered as efficient electrospun fibres.
Hybrid fuzzy-disturbance observer for estimating disturbance in styrene polymerization process
Authors: Shamsul Bahrin A. M. , Mohd Ali J.
Published: May 2020

In chemical process systems, disturbances such as heat loss, temperature and flow rate can affect the product yield and production costs. Therefore, observers are used to estimate the disturbance to obtain more stable and precise results. Observer is a computer software algorithm designed to estimate unknown parameters and can be used to replace sensors. This research aims to develop a hybrid observer by combining fuzzy logic and disturbance observer to overcome the limitation of the single observer known as fuzzy-disturbance observer. The hybrid observer will be applied in the styrene polymerization process to estimate the heat loss since it will affect the amount of heat in the reactor and reduced the product yield. The hybrid observer is also compare to a single disturbance observer and a fuzzy logic based observer to prove its effectiveness. The results show the effectiveness of this hybrid observer in estimating disturbance in styrene polymerization process. Further studies can be carried out to combine the hybrid observer with a controller to enhance the overall performances.
Intermolecular Interaction of Tween 80, Water and Butanol in Micelles Formation via Molecular Dynamics Simulation
Authors: Zakaria Junaidi , Rizal Abd Shukor Syamsul , Abd Razak Khairunisak
Published: May 2020

Micelles entrapment approach is one of the methods to synthesize silica nanoparticles as carriers for drug delivery system. This method is useful in enhancing drug solubility, extend the circulation of blood half-life and possesses lower toxicity. The shape and size of the silica nanoparticles could be excellently controlled by manipulating the parameters such as the concentration of surfactants and composition during the synthesis process. In this study, water and butanol have been used as solvent and co-solvent, while Tween 80 has been used as the surfactant. The structural properties of the micellar system from binary (water and Tween 80) and ternary (water, Tween 80 and butanol) were reported in terms of radial distribution function (RDF) and radius of gyration (Rg). The molecular dynamics simulations were performed using Material Studio by applying COMPASS Force Field in the Forcite Module. The simulation box was created by using Amorphous Cell Module. Initially, the simulation for both system was executed under a constant number of moles, volume and energy (NVE) ensemble for 200 ps and followed by a constant number of moles, pressure and temperature (NPT) ensemble for 2000 ps. From RDF analysis, both systems have the same distance of 0.97Å, but different value of g(r) intensity, 12 and 6.35 respectively. Meanwhile, the Rg result shows a higher value in ternary systems compared to the binary system. These findings revealed that the presence of butanol would weaken the intermolecular interaction of hydrogen bond and increase the size of the micelle and consequently will affect the size of nanoparticles.
Aiding Alarm Rationalization by Automatic Identification of various sequential patterns in large volume of Alarm and Event log data
Authors: Ghosh Kaushik , Krishnan Sivaprakasam Gokula
Published: May 2020

The main problem with modern Industrial Alarm System is that the operators receive far too many alarms than they can handle. Many of the alarms presented to the operators are nuisance in nature such as chattering alarms, redundant alarms, consequential alarms, and alarms with no action. Such alarms superfluously increase the alarm load to an operator, do not essentially indicate any real abnormal situation and more importantly do not require any corrective actions by the operator. Being overwhelmed by large number of nuisance alarms, operators always face tough challenge in identifying the real alarms which demands prompt operator actions and are often buried in the pool of nuisance alarms. It is therefore necessary to reduce the alarms loads of an operator by systematically identifying the nuisance alarms and presenting only the real useful alarms to the operators. Also, there are some alarms which require well defined operator actions to bring them back to normal. When these alarms get triggered operators are supposed to take a well-defined set of corrective action in order to normalize them. Identification of these alarms for which there is a consistent operator action would be of immense help since operators can immediately focus their attention on these alarms whenever they occur and carryout the necessary actions. The main goal of Alarm rationalization is to minimize alarm load to the operators by presenting only the alarms that are relevant and require operator actions. Alarm Rationalization process by and large is carried out manually. It is quite tedious, time consuming and requires a lot of manual efforts. To solve the these challenges and to aid in Alarm Rationalization process, a novel approach has been proposed in this paper for identifying the nuisance alarms by analyzing the large volume of Alarm and Event log data. Several Alarm Rationalization activities (such as: Changing Alarm Configuration settings, Alarm Suppression, Alarm grouping, Alarm removal, Alarm Prediction, Standardization of Alarm response Procedure) can be performed by based on the identified chattering alarms. The proposed approach is illustrated through some examples obtained by analysing the Alarm and Event log data from petrochemical and water treatment plants in Singapore.
Exploring the implementation barriers of eco-toilet system in the Philippines using Decision-Making Trial and Evaluation Laboratory (DEMATEL) approach
Authors: Ignacio J J J , Malolos C F , Mendoza N I , Lantin J , Orbecido A H , Promentilla M A B
Published: May 2020

Eco-Toilet system (ETS) is an emerging sanitation technology that promotes water conservation and nutrient recovery. Although many kinds of literature support the promising benefits of ETS, the implementation of such technology in the Philippines still faces a myriad of challenges. The study found out that the implementation of ETS in the country was affected by the following barriers: (a) policy and institutional capacity/commitment, (b) investment/financial issues, (c) technology and operation viability, and (d) social acceptance. DEMATEL was used as an analytical framework to investigate these key barriers. This method utilized the value judgments of experts and converted this information into quantitative data. Several computations were applied to reveal the causal relationships and prominence of the implementation barriers of ETS in the Philippines. Therefore, this study can benefit decision-makers in addressing implementation issues involving ETS projects in the country.