bluuebunny/crossref_metadata_2025 huggingface dataset:
On some mathematical models tracking epidemics spreading
Authors: Cerveró Jose M
Published: October 2021

A complete integrability of one SEIRD-like dynamical system is presented. Many models like this have been used nowadays in epidemiology and several other descriptions of virological spreading. In this paper we show that one of them is exactly solvable. Only one almost trivial condition for integrability is needed. The statistical perspective is not considered. Our solution is an exact one and the result hereby presented cast some doubts on the interest in this class of deterministic models. One entirely new avenue for tackling the problem of spreading diseases is then proposed. Curiously enough is surprisingly related to Quantum Mechanics in its non-hermitic version also called PT-Quantum Mechanics.
What is the resonant state in open quantum systems?
Authors: Hatano Naomichi
Published: October 2021

The article reviews the theory of open quantum system from a perspective of the non-Hermiticity that emerges from the environment with an infinite number of degrees of freedom. The non-Hermiticity produces resonant states with complex eigenvalues, resulting in peak structures in scattering amplitudes and transport coefficients. After introducing the definition of resonant states with complex eigenvalues, we answer typical questions regarding the non-Hermiticity of open quantum systems. What is the physical meaning of the complex eigenmomenta and eigenenergies? How and why do the resonant states break the time-reversal symmetry that the system observes? Can we make the probabilistic interpretation of the resonant states with diverging wave functions? What is the physical meaning of the divergence of the wave functions? We also present an alternative way of finding resonant states, namely the Feshbach formalism, in which we eliminate the infinite number of the environmental degrees of freedom. In this formalism, we attribute the non-Hermiticity to the introduction of the retarded and advanced Green’s functions.
Emergence of parity time symmetric quantum critical phenomena
Authors: Kumar Ranjith R , Rahul S , Kartik Y R , Sarkar Sujit
Published: October 2021

Emergence of different interesting and insightful phenomena at different length scale is the heart of quantum many-body system. We show that the physics of parity-time (PT) symmetry is one new addition to them. We show explicitly that the emergence of different topological excitation at different length scale for the PT symmetry system through the analysis of renormalization group (RG) flow lines. We observe that the higher order RG process favour the emergence of asymptotic freedom like behaviour and also show the effect of strong correlation on the emergent phases. Interestingly, the asymptotic freedom like behaviour is favoured by PT symmetry phase of the system. Moreover, we also derive the scaling relation for the couplings in RG equations. These findings can be tested experimentally in ultracold atoms.
Lung Cancer Detection using VGG NET 16 Architecture
Authors: Thanzeem Mohamed Sheriff S , Venkat Kumar J , Vigneshwaran S , Jones Aida , Anand Jose
Published: October 2021

Cancer is one of the main reason for loss of human life across the world. All the medical practitioners and researchers are dealing with the demanding situations to fight against cancer. Based on the report in 2019 from American Cancer Society, 96,480 deaths are anticipated due to skin cancers, 142,670 deaths are from lung cancers, 42,260 deaths are from breast cancers, 31,620 deaths are from prostate cancers, and 17,760 deaths are from mind cancers. Initial detection of most cancers has the pinnacle precedence for saving the lives. This paper proposed a lung cancer detection using Deep Learning based on VEE NET architecture. This was one of the famous models submitted to ILSVRC-2014. Visual checkup and manual practices are used on this venture for the various types of cancer diagnoses. This guide interpretation of scientific images that needs massive time intake and is notably susceptible to mistakes. Thus, in this project, we apply deep learning algorithms to identify lung cancer and its presence without the need for several consultations from different doctors. This leads to an earlier prediction of the presence of the disease and allows us to take prior actions immediately to avoid further consequences in an effective and cheap manner avoiding human error rate. In this project lung cancer and its presence is determined. A web application is developed as a hospital application where an input x-ray image is given to detect lung cancer.
Sustainable Development on Ferrock Mortar Cubes
Authors: Karthika S. , Leema Rose A. , Priyadarshini G.
Published: October 2021

Concrete, after water across the world, the second most broadly utilized material involving 8-10% of all yields of CO2, is predominantly because of cement. This project ultimately aims to determine the potential use of Ferrock as an exceptional replacement for cement in concrete compared with other alternative alternatives. It is a steel-based restraining compound used to form a carbon-negative structure substance utilizing waste material absorbents. The iron residue (an iron business loss) that would end in sites somehow alongside small quantities of limestone, metakaolin, and fly ash is being used to make this an efficient substance. Our research focuses unexpectedly on their commitment to carbon dioxide contamination, energy use, water use, the ecologic impact of ordinary Portland cement and Ferrock (limestone 8%, metakaolin 12%, fly ash 20%, and iron residue 60%). By subtitling concrete with Ferrock in fluctuating proportions of 5%, 10%, 15%, and 20% in solid, we attempt to find the ideal proportion of substitution, which, along with sustainability, would boost wanted outcomes for both (compressive and divided tensile). In all this proportion, the test result shows 10% is more efficient than others.
Relationship between California Bearing Ratio and Other Geotechnical Properties of Sub grade Soils
Authors: Mohammed Yimam , Paulmakesh A. , Admasu Bereket , Shukri Saliha
Published: October 2021

The California bearing ratio (CBR) is a very commonly used laboratory test for predicting the strength of subgrade layer. The aim of this study is predicting the strength of the subgrade soil from fine grained soils. The findings obtained from test results are Atterberg limit, grain size, compaction, and free swell tests. The California bearing ratios were conducted to find out the strength parameters, and correlated with liquid limit, plastic limit, plastic index, maximum dry density and optimum moisture content. The CBR values were determined in the laboratory are compared with the predicted values.
Design and Development of an Effective Smart Garbage System using the Internet of Things
Authors: Vanitha V , Sangeerth Raj CV , Mithun Kumar KK , Sebastian Joseph
Published: October 2021

Garbage management has become the most pressing challenge in today’s world, particularly in countries with significant population growth rates. Excess of gas can be formed in the environment which causes production of greenhouse gas in the environment. We employed this technology to monitor the level of waste in the garbage, as well as fire and gas emissions. When there is a fire or a significant volume of hazardous gas in the waste. The location will be updated in the web and the buzzer will give an alert. The whole process used to reduce greenhouse gas in the environment. And also, it detects the level of garbage, when the level is high it shares the location to IOT.
Fabrication and Tribological Studies of Hybrid Composite Material
Authors: Surendrababu K. , Sathiyaraj S , Issac Premson M. , GuruMugilan D. , Sridhran E.
Published: October 2021

Many attempts have been undertaken to mechanically or chemically create various types of in organic filled polymers. These methods, however, necessitate the alteration of the filler material through intricate polymerization reactions, making them unsuitable for industrial use. Waste flyash recovery is challenging, and the utilisation rate is poor. This flyash is employed in novel composite materials as a filler or partial reinforcement. Flyash is employed as a filler material for polymer matrix composites in this study. Aramid and E-Glass fibres are utilised as reinforcement with epoxy resin to improve the bonding strength between the fibres and filler materials, resulting in a high load bearing capacity. The specimens are tested for mechanical properties such as tensile, flexural, and impact according to ASTM standards. The maximal impact strength was seen at a 5wt% flyash addition, however the tensile and flexural strength were steadily lowered with the addition of 5wt% flyash.
Performance of Pellucid Concrete by using Optical Fibers
Authors: Subathra P. , Sangeetha S.P.
Published: October 2021

Energy efficient building and aesthetic view are the vital knot for infrastructure. Now engineers have developed smart translucent concrete(STC) using glass optical fibers (GOF). It can able to transmit light from one phase to the other phase of the wall. Smart translucent concrete is also known as pellucid concrete. Pellucid concrete reduces the consumption of electricity. Source of light can be taken from natural sunlight and artificial light source from LED having 20w. In this investigation, incorporating optical fibers in various diameters are 1.5 mm and 2.5 mm. Concrete cube with provision of hole for providing glass optical fiber and arranged in equal spacing of about 15 mm and 25 mm. In this experiment, analysis the performance of smart translucent concrete in the aspect of strength and luminance. The light intensity from the specimen can be measured with a help of photometer. It is an energy efficient building material innovated in recent years.
Effects of spatial resolution anisotropy on viscous terms using isotropic steady turbulence numerical analysis
Authors: Hirabayashi Riku , Suzuki Hiroki , Mochizuki Shinsuke
Published: October 2021

This study presents the effects of spatial resolution anisotropy on an isotropic turbulence field. Here, this turbulence field is steady. In order to set the anisotropy of the spatial resolution, the accuracy order of the viscosity terms is set to be anisotropic. The convection and viscosity terms are discretized using the second-order or fourth-order central difference schemes. The Reynolds number dependence of the turbulence statistics is used to examine this influence. The effects of resolution anisotropy on the small-scale turbulent field obtained by longitudinal derivatives as well as large-scale turbulent fields are small. On the other hand, the small-scale turbulent field obtained by lateral derivatives is significantly affected by the anisotropy of resolution in the low Reynolds number condition.
Dynamic numerical simulation of pre-cracked concrete samples under different mechanical parameters
Authors: Zhang W B , Wang S Y
Published: October 2021

Numerical simulations of pre-cracked concrete subjected to dynamic impact compressive stress wave are carried out via DRFPA (Dynamic Realistic Failure Process Analysis). This code is validated firstly by comparing experimental results. Then, the initiation, propagation and coalescence of wing cracks and secondary cracks are numerically investigated by varying elastic modulus, uniaxial compressive strength, and homogeneity index of some phases (bond and aggregate) of concrete. The numerically simulated concrete failure mode (tension/shear failure) and its development in both quasi-coplanar plane and concrete bridge are analyzed and discussed. Numerical results show that the tension failure occurs firstly whereas shear failure occurs shortly thereafter with continuous dynamic loadings and its reflected wave. Meanwhile, the evolution of wing cracks and secondary cracks are numerically investigated. In addition, the effect of elastic modulus, uniaxial compressive strength, and homogeneity index of concrete phases on the crack evolutions are also studied.
CFD-based investigation of R22 flow boiling characteristics in corrugated pipes
Authors: Wang J F , Zhu S L , Xie J
Published: October 2021

Double pipes are widely used in the food industry. In order to investigate the influence of different corrugation heights on the heat transfer performance of the corrugated pipe, the corrugated tubes with different sizes have been analyzed. The influence of different corrugation heights on the heat transfer coefficient and the pressure drop has been studied. An effect of the refrigerant velocity on the heat transfer coefficient and the pressure drop has been analyzed. The results show that the highest heat transfer coefficient takes place at the corrugation height 3.3mm. With an increase of the refrigerant velocity, the heat transfer coefficient and the pressure drop grow.
Experimental study of two organic phase change materials in cylindrical containers for battery module thermal management: a comparative analysis
Authors: Budiman A C , Kaleg S , Hidayat N A , Silalahi G N , Gani M N , Sudirja  , Amin  , Muharam A , Hapid A
Published: October 2021

Thermal runaway in battery Electric Vehicles (EV) is one of the most significant threats to their safety and overall performance. In this study, the use of saturated fatty acid and paraffin wax as phase change materials stored separately in a battery-like container, which acts as a thermal absorber for heat dissipation management, is analyzed. The melting characteristics between these two materials are relatively different, as shown from the Differential Scanning Calorimetry results. The fatty acid used in this study has a narrow melting point with its peak at 56°C, while the paraffin mixture has a wide range starting from as low as 37°C. The effect of such different profiles is translated to the difference in the measured temperature profiles. In passive thermal management based on PCM alone, the latent heat capacity is more important than having a melting range when the amount of PCM as heat absorber is strictly limited. However, when the PCM is evenly distributed, the paraffin tubes would have a better thermal profile than the fatty acid ones. Meanwhile, when the air blower is operated hence forming a hybrid thermal management system, there is almost no significant difference between the two PCM under investigation.
Study on Process Optimization and Performance of Low Formaldehyde Etherified 2D Resin
Authors: Liu Ma
Published: October 2021

With the improvement of people’s awareness of environmental protection and safety, formaldehyde emission from textiles is strictly restricted in many countries in the world. In this thesis, 2D resin was modified to prepare etherified 2D resin by a one-step process which is simple, time-saving, energy-saving, and quick reaction. The etherified 2D resin has low formaldehyde content, good handle and wrinkle resistance, and its comprehensive properties are superior to those of 2D resin.
Laboratory Evaluation on the Road Performance of Diatomite Modified Porous Asphalt Mixture
Authors: Liu H B , Liu H , Wei H B , Chai C , Zhu B
Published: October 2021

Porous asphalt mixture (PAM) is an indispensable pavement material for the construction of sponge city with low-cost and environment friendly characteristics, which conducive to replenishing urban groundwater and alleviating the heat island effect. The main purpose of this article is to explore the change of road performance and water permeability of PAM under different diatomite dosage, and determine the optimal amount of diatomite content. First, the volume characteristics of diatomite permeable asphalt mixture (D-PAM) were measured by Darcy’s law, the void of D-PAM decreased slightly according to the test results. Furthermore, based on the water damage Marshall test and freeze-thaw splitting test, the water stability of D-PAM increases significantly with the increase of diatomite content. At last, the low-temperature anti-cracking performance and ductility of D-PAM were carried out based on the acoustic emission (AE) detector and the Low temperature universal mechanics testing machine. According to the experimental results, it is recommended that the content of diatomite is 10%.
Longan Leaves biomass-derived renewable activated carbon materials for electrochemical energy storage
Authors: Taer Erman , Tampubolon Desy Kristin Harida , Apriwandi  , Farma Rakhmawati , Setiadi Rahmondia Nanda , Taslim Rika
Published: October 2021

Biomass-based energy conversion and storage applications have proven to be the most effective technology for practical and sustainable applications. However, their further development was hindered by poor electrode performance. Naturally, abundant biomass is a green alternative carbon source with many desirable properties. This study presents a relatively easy approach for the synthesis of activated carbon-based electrode materials derived from natural biomass with an emphasis on supercapacitor applications. The selected biomass waste is Longan leaves. The precursor was converted into activated carbon through ZnCl2impregnation at three different concentrations in high-temperature pyrolysis. All activated carbon confirmed a good amorphous structure. Furthermore, oxidative compounds were also found to have an effect on their electrochemical properties. supercapacitor cells prepared in a two-electrode system exhibit high electro-capacitive properties with a specific capacitance of 169.83 F g−1at a constant current density of 1.0 A g−1in an aqueous electrolyte of 1 M H2SO4. Furthermore, the optimum energy density was found in LF0.5 samples as high as 19.04 Wh kg−1at a maximum power density of 124.37 W kg−1.
Coupling Backpropagation Neural Network and AdaBoost Algorithm for Quantitative Analysis of Nickel via Laser-Induced Breakdown Spectroscopy
Authors: Harefa Edward , Zhou Weidong
Published: October 2021

A wide area of cropland or soil might well be contaminated with heavy metals, contaminating agricultural goods and posing a risk to human health. As a result, it is required to evaluate the concentration of heavy metals in soil. The combination between laser-induced breakdown spectroscopy (LIBS) and multivariate chemometrics methods was employed to determine heavy metal Ni concentration in twelve soil samples. The comparison between univariate calibration curve, traditional backpropagation neural network (BPNN), and hybrid BPNN-AdaBoost was presented. The result revealed that BPNN-AdaBoost outperformed other models with the coefficient determination calibration(RG2), coefficient determination prediction(RP2), root mean square error calibration (RMSEC), root mean square error prediction (RMSEP) are 0.985, 0.977, 2.04, 3.18, respectively. This study indicates that BPNN-AdaBoost can be adopted as a reliable chemometric technique to enhance the quantitative analysis of heavy metals based on LIBS.
Less Expensive and Eco-Friendly Preparation of Activated Carbon Derived from Coffee Leaf as an Supercapacitors Electrode
Authors: Taer E , Gultom E S , Agustino  , Taslim R , Febriani W
Published: October 2021

In this paper, less expensive and eco-friendly biomass-based activated carbon from coffee leaf (CL) was prepared as electrode materials for supercapacitor applications using KOH activation, carbonization, and physical activation in a CO2atmosphere. Using cyclic voltammetry and galvanostatic charge/discharge techniques, the CL sample was tested in a two-electrode configuration operating in 1 M H2SO4. After physical activation, the percentage reduction of the mass, diameter, thickness, and diameter are 76.47%, 29.38%, 28.57%, and 38.04%, respectively. The CL sample exhibits specific capacitance, energy and power densities of 210 F/g, 29.17 Wh/kg, and 39.99 W/kg at constant current 1 A, respectively. Therefore, the CL sample obtained through KOH activation, carbonization, and physical activation using CO2atmosphere has a promising future applied as an electrode material for supercapacitor applications.
Matoa Fruit peel-based Activated Carbon and its Application as an Electrode Materials in Supercapacitor Devices
Authors: Taer Erman , Agustino  , Taslim Rika
Published: October 2021

The use of matoa fruit peel waste-based activated carbon as electrode materials for supercapacitor devices is described in this paper. The chemical and CO2 activation were used to prepared the activated carbon. In the chemical activation process, zinc chloride 0.1 M was used as a chemical reagent. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements are used to assess the electrochemical performance of as-prepared electrode materials. After CO2 activation process, the density of the MFP samples have been decreased. From the CV and GCD data, the MFP-0.1 sample has optimum specific capacitance are 158 F g−1 and 187 F g−1, respectively. The electrochemical results demonstrated that the MFP sample is a potential choice for supercapacitor electrode materials.
The Effect of Support on the Catalytic Efficiency of MnO2/Activated Carbon for degradation of Methylene blue
Authors: Yanti Aurora SD , Sophia Halida , Anggraini Riska , Siregar Siti Saidah , Awaluddin Amir
Published: October 2021

Methylene blue (MB) is a blue cationic thiazine dye which is widely used in cotton fiber, wood and textile industries, but has an adverse effect to environment and living organism. It is urgent to find an alternative and effective solution for this recalcitrant compound. The Fenton process-based advanced oxidation process is considered as an effective method for the degradation of organic contaminants such as dyes. In this study, the composite α-MnO2/activated carbon (AC) was first synthesized by a facile, one-pot synthesis using sol-gel method and characterized by X-ray diffraction (XRD) and BET surface areas. The XRD results indicated that the tunnel cryptomelane-type manganese oxide (α-MnO2) was successfully synthesized as the minor phase in the activated carbon support. The composite α-MnO2/AC has higher specific surface area than the single α-MnO2. The catalytic studies indicated that the α-MnO2/AC has a much higher catalytic efficiency over single α-MnO2 for degradation of MB. The presence of the support and the increase in surface area of α-MnO2/AC could be responsible for its higher catalytic efficiency compared to single α-MnO2. In the optimum condition, the α-MnO2/AC was able to degrade 98.48 % and 99.2 % of MB within 10 and 120 minute of reaction time, respectively.
Constructivism-Based Magnetic KIT Design as a Science Learning Media
Authors: Ridho Muhammad , Rahmad M. , Wulandari Sri
Published: October 2021

Some students still feel foreign to hear about electrical material because the material that is passed by some considers it to be still abstract. So that the concept of electric magnetism is still a lot of misconceptions. Based on the research, there are also some teachers who make assignments to students for experiment at their respective homes which makes students not do experiment but imitate the existing theory. The research aims to design a magnetic KIT that can be used for practicum at school. This study uses a 4D development model which is limited to the media development stage. The development of KIT magnets designed with four experiments with precision values in each of experiment have a very high range from 0.93 to 0.99 which it can be categorized high and the highest precision. So that from very high precision the error percentage of the magnetic KIT experiments are the lowest ranging a the lowest precentage 1.8%-9.7% which is categorized as a very low percentage of the magnetic KIT device. So the accuracy of the magnetic KIT device can be said to be very high. For the first and second experiments the results obtained are not much different from the existing theory. The percentage of errors for the first and second experiments ranged from 1.8%-8.6% while the third and fourth experiments were carried out repeatedly but the results were not much different or almost the same.
A preliminary study of a landfill as a raw material for RDF: a case study in Medan City
Authors: Rhoshenia D A , Utami R , Khair H
Published: October 2021

The increase in population is directly proportional to the use of goods/materials, resulting in the volume of waste produced. If it is not processed, an increase in the volume of waste will lead to the emergence of piles of waste and the need for landfill land to accommodate waste is higher. One solution to solve the waste problem is to convert waste into fuel through Refuse Derived Fuel (RDF). This research aimed to study the characteristics of the landfill and its potential as an RDF raw material. The research was conducted at the Terjun Landfill in Medan. This study found that the water content of the waste ranged from 12.88 percent to 38.35 percent, the ash content from 0.625 percent to 1.575 percent, and the calorific value from 12,13 MJ/Kg to 36,58 MJ/Kg. According to the findings, inorganic combustible fraction waste can be used as a raw material for RDF and a substitute for coal.
Using Hawgent Mathematics Software to Help Primary School Students to Read Clocks
Authors: Pereira Jerito , Jianlan Tang , Wijaya Tommy Tanu , Purnama Aditya , Hermita Neni , Tamur Maximus
Published: October 2021

Clock reading is a very important skill for students however there are still students that finds clock reading difficult to understand. Technology can help students to understand mathematics concepts. This research developed a learning media using the research and development method and the ADDIE framework. The sample of this research are 87 students from Bandung, Indonesia. The learning media is made based on the analysis of teachers’ and students’ difficulties on clock reading. The result of this research shows that Hawgent dynamic mathematics software can help students to understand clock reading. The learning media also received a positive response from the students. During the teaching and learning process, students were more active in answering the teachers’ questions and were able to follow the instruction given. This research proved that technology can help students in various aspects that includes getting students’ attention so that they more focused in learning mathematics. The use of technology can be used for various topics in various grades.
A Comparison of Bagging and Boosting on Classification Data: Case Study on Rainfall Data in Sultan Syarif Kasim II Meteorological Station in Pekanbaru
Authors: Adnan A , Yolanda A M , Natasya F
Published: October 2021

A frequent way for classification data is using a machine learning algorithm alongside ensemble methods like bagging and boosting. In earlier studies, these two algorithms have shown to be very accurate. The aim of this research is to discover performance of bagging and boosting to classify rainfall data obtained at the Sultan Syarif Kasim II Meteorological Station in Pekanbaru from 1 January 2018 until 31 July 2021. Rainfall data are classified into two categories: rainy and non-rainy. The parameters are average temperature, average humidity, sunshine duration, wind direction at maximum speed, and average wind speed. For comparison, this study developed Stochastic Gradient Boosting with Gradient Boosting Modelling and C5.0 from boosting, as well as Bagged Classification and Regression Tree (CART) and Random Forest from bagging. In order to generate reliable conclusions, each algorithm is run 30 times with repeated cross validation. The result demonstrates that Stochastic Gradient Boosting with Gradient Boosting Modelling is the best algorithm based on average accuracy.
Item Analysis of Heat Transfer Concept Using Rasch Model in Elementary School
Authors: Hermita N , Sakinah S , Wijaya T T , Vebrianto R , Alim J A , Putra Z H , Fauza N , Dipuja D A , Pereira J , Jihe C
Published: October 2021

This study aims to analyze test items of heat transfer instructional materials using the Rasch model to obtain information on the Wright map, item measure, item fit, and item reliability. This study applied a quantitative-descriptive research design. The subjects in this study were 75 fifth graders of State Elementary School 192 of Pekanbaru. The students were asked to do 11 essay items. Students' responses on the essay items were collected through Google Form. The collected data were then analyzed using the Rasch model on the Winstep® application version 3.73. Based on the data analysis, item 2 and 3 were the most difficult items, and item 10 was the easiest item. All items are at a moderate difficulty level. There was an invalid item of 11 items. The item reliability value was 0.75 which meant sufficient. In conclusion, the 10 test items (1 is invalid) are selected for inclusion in the achievement test to measure the students' understanding of heat transfer instructional materials.
The Groundwater Analysis using Geoelectric Method Wenner Rules in Rejosari Village, Tenayan Raya Pekanbaru
Authors: Juandi M , Ginting E N
Published: October 2021

The interpretation of groundwater in Rejosari Village, Tenayan Raya, Pekanbaru City has been carried out using geochemical and geoelectrical methods using Wenner-Schlumberger rules. This study aims to identify aquifer layers, determine flow patterns, and groundwater quality. Measurements were made on two tracks with a length of 68 m and 100 m respectively. Based on the results of data processing, it is known that the groundwater aquifer layer is at a depth of up to 5–15 m below the surface with a resistivity value 9.4-160.40 m. The pattern of groundwater flow in the study area tends to spread and is located at a certain depth. In track one, the aquifer layer is on the upper surface, while for track 2 the distribution is to a depth of 18 meters. The lithology of the subsurface layer in this study area is a layer of peat with a resistivity value 138.9–170.8 m, gravel with a resistivity value 117.4–160.4 m, and sandstone with a resistivity value 117.4–170.8 m.
Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast
Authors: Contreras J , Haro Y , Gelves G
Published: October 2021

A dynamic model is presented to simulate a fermentation process for bioethanol production from banana rejected using a batch system. The critical model feature is using an inhibition function to relate substrate concentration and specific growth rate. Kinetic parameters were calculated based on previous experimental data, and the optimal substrate concentration is investigated. The Andrews kinetic model was adapted to the concentration profiles, indicating that it could describe the existence of substrate and product inhibition. Different initial substrate concentrations were evaluated (90-400 g/L), and simulated results suggest 200 g/L of rejected banana as a starting point to reach a high and efficient bioethanol production since a maximal ethanol production is reached with a value of 150 g/L. However, when using a higher banana, rejected concentration inhibition occurs, and therefore bioethanol production decreases to reach levels lower than 100 g/L. Based on results found, kinetic models allow obtaining important observations on microbial metabolic processes and facilitating a good approximation for further large-scale stages.
Cellulase Production from Trichoderma harzianum: a Framework Modeling for Evaluating Different Operating Mode Strategies
Authors: Mora D , Carrillo F , Gelves G
Published: October 2021

The cellulase enzyme has been used in essential applications in the textile industry and the formulation of some medicines. Therefore, a mathematical model based on previous reports is proposed for cellulase enzyme enhancement. First, the kinetic constants were taken from the literature. Then, two operating strategies were carried out to maximize cellulase production using 10g/L of cellulose and 0.4g/L of cells as a first strategy using a batch mode. Alternatively, a second operating mode is simulated using continuous cellulose feeding. Finally, a comparative analysis was made for determining the best operating mode related to maximal cellulase production. Interestingly, the continuous mode shows a high cellulase concentration lasting a shorter time than the batch mode to avoid inhibiting enzyme production. One of the most important findings of this work focuses on increasing cellulase production with values of 1800 FPT/L simulating the continuous mode. The latter suggests that cellulase production could be double the concentration obtained with the traditional batch mode (800FPU/L). Results obtained in this research may be promising for the enzyme production industry. Using simulation techniques, it is possible to determine an enhancement without requiring excessive experimentation and resources.
Efforts to Prevent Land Fires through the Use of Potential Peatlands in Coastal Areas
Authors: Syahza Almasdi , Nasrul Besri , Suwondo  , Irianti Mitri , Meiwanda Geovani
Published: October 2021

The development of the agricultural sector for coastal communities, especially on peatland plays an important role in the structure of the regional economy. In Riau province, there are potential peatlands of approximately 64% of the total land area, that support the local people's lives, especially for agriculture. These peatlands also have various ecological functions such as flood and global climate controls. Therefore, this study aims to determine efforts to prevent land fires through the development of superior commodities in potential peatlands. This study was carried out through a survey using the developmental research method and the data were collected with a participatory rural appraisal (PRA) approach. The food crops cultivated on the peatland were rice, corn, and cassava, and were carried out for the first 2-3 years. Furthermore, long-term crops such as rubber, sago, and coffee were also planted. The results showed that the use of peatland with an economic value has a positive impact on its management. Therefore, this effort is capable of preventing the occurrence of land fires.
Numerical Analysis of Filtering Circuit for Partial Discharges
Authors: Liew H F , Ariefbillah A B , Syed Akhmal J , Junaidah A M J , Norhanisa K , Muhammad Izuan R F
Published: October 2021

Partial Discharge (PD) is a small electrical spark that happens within the insulation of medium and high voltage electrical assets. It is important to note that the discharge will erode the insulation and eventually result in disastrous insulation failure. Thus, PD detection is a crucial issue in high voltage insulation area. However, the on-site field PD tests, the high frequency PD signals detected by sensors, are vulnerable to interferences and background noises. This has a negative effect on high voltage apparatus fault diagnosis and localization accuracy. For that reason, noise suppression has become an urgent and vital issue for field high frequency PD signal testing. Thus, this research aims to model a filtering circuit to suppress the noise along with PD in high frequency measurement. A filtering circuit was analysed by using Proteus software to filter out the noise along with PD with decent accuracy and efficiency. Then, performance investigation of active high pass and passive high pass was conducted and studies to filter out PD noise suppression in high frequency were successfully developed. The active filter was focusing on the first order stage until fourth order stage. The passive filter only concentrated on two types of order stage; first order stage and second order stage. The result demonstrated that active high pass filter presented the best performance with low decibel frequency response (-20 dB), and was suitable for this research purpose compared to passive high pass filter. Besides, 700 Vrms has been selected to check the response at high voltages and the frequency values set at 50 Hz for low frequency and 8 kHz for high frequency. This specification design values have been selected because it is suitable for situations in high-tension power line. This type of filtering circuit is suitable to be used for academic and lab experimentation.
Conceptual Design of Gravitational Water Vortex Turbine for Green Energy Generation
Authors: Camillus J , Mat Tokit E , Mohd Rosli M A , Mohd Sa’at F A Z , Herawan S G , Syahputra S I A
Published: October 2021

In this study, the conceptual design of a gravitational water vortex turbine has been developed. The conceptual turbine was designed to extract the energy from the house rooftop and generate the small power electricity using design principles. Through the concept of the House of Quality, the respondent requirements data were extracted to match with the scientific view in the design of the turbine. The data from the respondent was then linked to respond to the product characteristics by decomposing the function of the turbine. The divergence of three conceptual designs was being developed by cross-linking the part selection through the morphological chart. Of all designs, the final turbine design has been selected based on the concept of screening through the Pugh method and the concept of scoring of a weighted-decision matrix. Design 3 had been selected as the final product of this conceptual design study when the angle of the inlet opening is at 60°, the angle of pre-rotational is at 30°, with 3 number of blades, and when the body material is set as of polyvinyl chloride.
Influence of inlet velocity and heat flux on the thermal characteristic of various heat sink designs using CFD analysis
Authors: Khor C.Y. , Rosli M.U. , Nawi M.A.M. , Kee W.C. , Ramdan Dadan
Published: October 2021

A heat sink is an important passive heat exchanger in the thermal management of electronic devices or systems. The study aims to analyze the influence of the inlet velocity and heat flux on the thermal characteristics (i.e., static temperature and heat transfer coefficient) of three heat sink designs. Computational fluid dynamics (CFD) analysis is carried out for the electronic cooling process. Three heat sink designs, namely, circular pin fin, plate fin, and rectangular fin are considered in this study. The influence of the inlet velocity and heat flux on the temperature distribution and heat transfer coefficient was analyzed. The results revealed that the use of circular pin resulted the highest temperature drop when the inlet velocity increased. The highest heat transfer coefficient was observed on the circular pin fin design during the cooling process. The heat flux demonstrated a linear correlation with the temperature for all heat sink designs. The effectiveness of the heat transfer was attributed by the heat sink design and inlet velocity of the airflow. Thus, the current results indicated the thermal characteristics of the heat sink are crucially influenced by the design and velocity of airflow in the cooling process.
Simulation-enabled Design and Analysis of Globe Valve
Authors: Nuri Al-Amin Nu’man Al-Basyir Mohd , Abdul Rani Ahmad Majdi , Awang Mohd Norhisyam , A Rani M Nasir , Ishar Nur Athirah , Thompson Harvey M. , Hafizun Hassan M , Zakir Bushra Mohamad , Hassan Ahmad Tarmizi
Published: October 2021

Globe valves serve many purposes in oil and gas facilities as a tool to control fluid flow in pipelines. However, older designs of globe valves suffer many problems and faults, mainly from valve leakage and valve passing. In mitigating these problems, this paper will improve the design of a globe valve to enhance its fluid flow performance and reduce the pressure difference value throughout the valve. The improvements on the valve will be validated from the original design with the help of Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA). The project concluded that the improved valve design performs better than the original design in all aspects except in terms of valve passing at the contact seal between the seat and the disk in a fully closed position. Implementation of smart sensors and prototyping will be explored in future studies.
Effect of loading protocol on the mechanical properties of 316L stainless steel
Authors: Heng S.H. , Muhamad Azmi M.S. , Rojan M.A. , Hashim M.S.M. , Ayob M.N. , Ismail A.H. , Abdul Manan M.S. , Abdullah S.
Published: October 2021

Two types of loading protocol, i.e., monotonic loading and cyclic loading, were compared to investigate the effect on the mechanical properties of 316L stainless steel. The specimen used is a dog-bone specimen in accordance with ASTM E8 and ASTM E606 standard. For cyclic loading, the multiple-step method is used to obtain the hysteresis loop of the material. A total of 13 strain amplitude conditions had been carried out, ranging from 0.05%-0.65%. The stress-strain curve shows that the cyclic stress-strain curve is higher than the monotonic stress-strain curve due to the cyclic hardening behaviour in the 316L stainless steel. The cyclic hardening behaviour increases the ultimate tensile stress of the material. However, when the material gains its strength through cyclic hardening, the ductility in the material will decrease.
Structural Analysis on the Coil Spring of Motorcycle Suspension System
Authors: Tan W H , Lo W C , Teoh C Y , Cheng E M
Published: October 2021

The motorcycle suspension system is one of the crucial components. It helps to support the motorcycle’s weight, isolate the vibration level caused by road imperfection, and keep the wheel in contact with the road surface. Therefore, the performance of suspension system needs to be enhanced to ensure the ride comfort and safety of riders. Coil spring is one of the essential parts of motorcycle suspension system. In this study, two different materials of coil spring are being focused include steel alloy and carbon fiber reinforced plastic (CFRP). The geometry of the coil spring is the existing design in the market. The static structural analyses are carried out to determine the directional deformation of y-axis, equivalent stress and equivalent elastic stress analysis of the corresponding coil spring material. The obtained results are discussed. It is found that the steel coil spring has better performance for the existing coil spring design. The directional deformation, equivalent stress and equivalent elastic strain of steel coil spring are considered at the lower side, which is 0.029357mm, 2003MPa and 0.010051mm/mm respectively. In this study, it is observed that the number of turns of coil spring should be increased to enhance the performance of CFRP coil spring.
Analysis of energy absorption of aluminium foam fenders under axial loads
Authors: Djamaluddin Fauzan , Mat Fauziah , Sarah Zulfhis , Ahmad Masniezam , Renreng Ilyas
Published: October 2021

In shipping, a fender is a bumper that is used to reduce collisions that occur when the ship is about to dock or when the ship is moored by waves or currents in the port. To be able to damp, fenders should demonstrate high energy absorption and low reaction force. Therefore, fenders are generally made of rubber, elastomeric foam, or plastic. In this research, we aim to examine the effect of aluminium foam as one of fender components and to measure if the foam works for damping and allow fender to reduce force. It can be an innovation for fender design because the use of aluminium means a possibility in extending the fender life, minimize replacement and maintenance costs. This research examines 4 variations of the cross-section of the fenders to which aluminium foam have been added. Fender testing is done by conducting crashworthiness and impact tests of the developed fender model by employing Abaqus software. Based on the simulation result, aluminium foam shows a significant role in reducing the pressure generated by the load through the high energy absorption of the aluminium foam using finite element analysis. In conclusion, the foam filled fenders exhibit constant stress which can absorb higher energy levels than that of the empty fenders.
Compressive strength, sound absorption coefficient (SAC) and water absorption analysis of HDPE plastic waste reinforced polystyrene and Portland cement for lightweight concrete (LWC)
Authors: Manaf Izzati Abdul , Marsi Noraini , Genesan Vikneshvaran , Yusrianto Efil , Shariff Hafizuddin Hakim , Adnan Suraya Hani , Awang Mariah , Ali Roslinda , Mohd Jamir Mohd Ridzuan
Published: October 2021

This project research presents compressive strength, sound absorption coefficient (SAC) and water absorption analysis of High-Density Polyethylene (HDPE) plastic waste reinforced polystyrene and Portland cement for lightweight concrete (LWC). The research is aimed into the issue of waste materials such as HDPE plastic waste and polystyrene waste into lightweight concrete (LWC) application. Modifications with waste material may improve the qualities of lightweight concrete (LWC), and HDPE plastic waste may serve as a partial substitute for natural aggregates, which are rapidly depleting. It has been proposed that HDPE plastic waste and polystyrene be used as an alternative aggregate material to reduce environmental impact. In this study, four composition ratio of HDPE plastic waste reinforced polystyrene and Portland cement to produce LWC; which are (a) 0.5 HDPE plastic waste : 1.0 polystyrene: 1.0 Portland cement, (b) 1.0 HDPE plastic waste : 1.0 polystyrene : 1.0 Portland cement, (c) 1.5 HDPE plastic waste : 1.0 polystyrene : 1.0 Portland cement, and (d) 2.0 HDPE plastic waste : 1.0 polystyrene : 1.0 Portland cement. The highest rate of compressive strength attained was 97.28 kN with the composition ratio of 1.5 HDPE plastic waste: 1.0 polystyrene : 1.0 Portland cement. It was discovered that a larger proportion of plastic lowered the strength of concrete. On the other hand, the optimum composition ratio of HDPE plastic waste reinforced concrete for lightweight concrete (LWC) produces the appropriate strength for LWC when the composition ratio is optimized. For sound absorption analysis, the higher coefficient is 0.42 SAC at 350 Hz to 1500 Hz for the composition ratio of 1.5 HDPE plastic waste : 1.0 polystyrene : 1.0 Portland cement. Water absorption characteristics of HDPE plastic waste and polystyrene for LWC dropped with increasing plastic waste content up to 0.50%.
Microstructural and Physical Properties of Yttria Stabilized Zirconia (YSZ) Prepared by Ceramic Injection Moulding (CIM)
Authors: Zainudin M , Ismail M H , Shaari N S , Manap M F A , Yahaya M
Published: October 2021

Ceramic injection moulding (CIM) is a near net shape process to produce smaller and intricate parts at a competitive cost. However, fine particle size (nano scale) used for such injection moulding process generally leads to agglomeration, higher binder content and critical dimensional shrinkage which results in defects on the sintered components. This study extensively investigates the characteristics of Yttria Stabilized Zirconia (YSZ) for CIM process. YSZ parts were moulded by CIM process that utilized a multi-component binder system using palm stearin (PS) and polyethylene (PE) in 60:40 (vol %) ratio. The powders were characterized using particle size analyzer, pycnometer density and scanning electron microscopic (SEM). The binders were characterized by the pycnometer density, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Powders loading were choosen by the critical powder volume percentage (CPVP) through oil absorption test. YSZ powder was mixed with the binders at different powder loadings ranging from 58 to 60 vol% based on CPVP. The parts were injected moulded, thermal debound, pre-sintered and sintered. The microstructure, green strength and hardness of the sintered part at different powder loadings were investigated. A large porous region was clearly observed at 58 vol% compared to 60 vol%. All samples were sintered at 1350°C, with the highest green strength and hardness were 13MPa and 357.42 HV respectively was given by the sintered part at powder loading of 60 vol.