bluuebunny/crossref_metadata_2025 huggingface dataset:
Determining the temperature-dependent London penetration depth in HTS thin films and its effect on SQUID performance
Authors: Keenan Shane , Pegrum Colin , Gali Labarias Marc , Mitchell Emma E.
Published: October 2021

The optimum design of high-sensitivity Superconducting Quantum Interference Devices (SQUIDs) and other devices based on thin high-temperature superconductor (HTS) films requires accurate inductance modeling. This needs the London penetration depth λ to be well defined, not only at 77 K, but also for any operating temperature, given the increasingly widespread use of miniature low-noise single-stage cryocoolers. Temperature significantly affects all inductances in any active superconducting device, and cooling below 77 K can greatly improve device performance; however, accurate data for the temperature dependence of inductance and λ(T) for HTS devices are largely missing in the literature. We report here inductance measurements on a set of 20 different thin-film YBa2Cu3O7−x SQUIDs at 77 K with thickness t = 220 or 113 nm. By combining experimental data and inductance modeling, we find an average penetration depth λ(77)=391 nm at 77 K, which was independent of t. Using the same methods, we derive an empirical expression for λ(T) for a further three SQUIDs measured on a cryocooler from 50 to 79 K. Our measured value of λ(77) and our inductance extraction procedures were then used to estimate the inductances and the effective areas of directly coupled SQUID magnetometers with large washer-style pickup loops. The latter agrees better than 7% with experimentally measured values, validating our measured value of λ(77) and our inductance extraction methods.
Carrier–carrier Coulomb interactions reduce power factor in organic thermoelectrics
Authors: Koopmans Marten , Koster L. Jan Anton
Published: October 2021

Organic semiconductors are excellent candidates for low temperature thermoelectric generators. However, such thermoelectric applications require materials be doped and highly conductive. Here, we show how doping affects the Seebeck coefficient in organic semiconductors using kinetic Monte Carlo simulations. Employing a hopping transport approach, we demonstrate that at high dopant loading, carrier–carrier interactions can reduce the Seebeck coefficient. This results in systems with intrinsic disorder, still following Heike's formula for thermopower at high dopant density. Reducing these carrier–carrier interactions results in an increased Seebeck coefficient and power factor. Specifically, a realistic reduction in carrier–carrier interactions can increase the power factor by more than a factor 15, increasing ZT above 1 for organic thermoelectrics.
Omah Cagak Wolu: The Rural Javanese House Architecture In The Cetho Temple Area Of Lawu Mountain, Indonesia
Authors: Ikhsan Fauzan Ali , Setioko Bambang , Suprapti Atiek
Published: October 2021

The architecture of Javanese houses in the Cetho Temple area is a variant of Javanese rural house architecture that has its uniqueness. Cetho Temple is one of the relics of Hinduism during the end of the Majapahit Empire. The climatic conditions of Mount Lawu and the spatial interaction with the Cetho Temple complex affect the concept of thinking and building Javanese houses and their settlement. The adaptation and adjustment processes that take place from generation to generation produce a typology of rural Javanese houses with local characteristics. This study aims to provide an understanding of the architectural characteristics of rural Javanese houses with a Hindu Javanese cultural background in the Cetho Temple area. The research location is in Cetho Hamlet, Gumeng Village, Jenawi District, Karanganyar Regency. The method of selecting the Javanese house research sample was carried out purposively by considering the typology and age of the house to represent the original character of the settlement. The results of the study found that the Javanese rural house in Cetho Hamlet has the characteristics of eight saka (poles). The Cetho people call it Omah Cagak Wolu. Omah Cagak Wolu is one of the typology variants of Javanese houses that are known around the slopes of Mount Lawu. Omah Cagak Wolu shows the interwoven space and function of a rural Javanese house in the Cetho Temple area. The typology of the Omah Cagak Wolu is a response to the mindset of rural Javanese people who are Hindu and the natural conditions on the slopes of Mount Lawu.
The Development of Smart Irrigation System With IoT, Cloud, and Big Data
Authors: Badrun Burhanuddin , Manaf Murshal
Published: October 2021

Irrigation management in several developed countries now uses modern technology by utilizing the capacity of the Internet of Things and Big Data for leak detection, water measurement, planning, monitoring and distribution. The Internet of Things provides new solutions for the irrigation sector and helps improve irrigation management and reduce operational costs associated with maintaining infrastructure. One of the biggest problems facing smart irrigation systems in Indonesia is the inability of stakeholders to convert available data into in-depth and accurate information that can be used in decision making. The purpose of writing this article is to prepare the concept of building a smart irrigation system for the sustainable use of water for stakeholders. Analysis and approaches are carried out by reviewing the development of smart irrigation systems from the perspective of Industry 4.0 (big data and internet of things), identifying the use of IoT-based technology, innovation and data-science best practices that can transform organizations and institutions, irrigation users become more data-centered centric artificial intelligence. The results of this study propose innovative simple semantic solutions to help irrigation users or farmers to measure humidity, rainfall, wind speed, soil temperature and solar radiation in real-time through mobile application information to the water user community.
The Evaluation of The use of Palm Shell Ash Waste to Polymer Modified Asphalt Mixture
Authors: Bethary Rindu Twidi , Intari Dwi Esti , Fathonah Woelandari , Andika Solehan
Published: October 2021

The palm oil industry’s development has a strategic role in Indonesia’s economy because Indonesia is the largest country and the largest exporter of palm oil globally. On the other hand, a new problem arises from increasing palm oil ash waste. This has encouraged the use of palm oil ash as filler mix asphalt. In this study, an evaluation of the asphalt mixture’s performance on the surface layer (AC-WC) will be carried out by utilizing palm ash waste as a filler using Starbit E-55 polymer asphalt. Testing the asphalt mixture’s performance using the Marshall method with asphalt content of 6% ± 0.5 and variations in the percentage of palm ash filler used, namely 3, 4, 5, and 6%. Samples are prepared and tested to obtain the stability and volumetric values of the mixture. Based on the results, it was found that the addition of palm ash waste as a filler could increase the stability performance at 3% filler content but there was a decrease in the filler content of 4, 5, and 6% in the test object without the addition of palm ash filler, the highest stability was obtained, namely 2358, 4 kg while the test object with the addition of 3% palm ash filler has a stability of 2503.03 kg at each asphalt content of 6.5%. The flow parameter in the test object continues to decrease along with the increase in the addition of oil palm ash filler, this is in line with the increase in the Marshall Quotient parameter which causes the mixture to become stiffness, this indicates that the mixture can withstand deformation due to traffic loads and shows that this oil palm ash potentially suitable for use as a filler in asphalt mixtures.
Synthesis of Composite Membrane Based Biopolymer Chitosan With Silica From Rice Husk Ash For Direct Methanol Fuel Cell Application
Authors: Purwanto Mochammad , Widiastuti Nurul , Saga B. H. , Gusmawan Heldy
Published: October 2021

A membrane chitosan with silica from rice husk ash was fabricated as alternative membrane electrolyte for direct methanol fuel cell (DMFC) application. Chitosan is made from shrimp shell powder which is processed through deproteination, demineralization and deacetylation steps. Furthermore, the phase diversion technique was used to synthesis membranes by mixing chitosan and silica in acetic acid solution. The resultant membrane characterized with FTIR, water and methanol uptake, ion exchange capacity, and methanol permeability. FTIR analysis showed that chitosan and silica was successfully synthesized. Water uptake for the chitosan-silica membrane increased with increasing silica loading, but the methanol uptake value decreased. The chitosan-silica with 15 wt% silica loading exhibited the best ion exchange capacity and methanol permeability which were 1.290 meq/gram and 2.42 x 10−4 cm2/s, respectively. All the result obtained from this studi shown that chitosan-silica membrane is a promising electrolyte membrane for direct methanol fuel cell application.
Determination of Weathered Layer Thickness Around the Landslide Zone using the Seismic Refraction Method
Authors: Hadi Arif Ismul , Brotopuspito Kirbani S , Pramumijoyo Subagyo , Hardiyatmo Hary C
Published: October 2021

The thickness of the weathered layer in the landslide zone can be determined by the seismic refraction method. This study aims to determine the thickness of the weathered layer based on the primary wave velocity (P-wave or Vp
). Data acquisition is taken around the landslide zone, namely above the landslide, parallel to the landslide, and perpendicular to the landslide. The data were collected using a digital seismograph 16S24. Furthermore, the data obtained in the field is processed to obtain a 2-D model. The results showed that the thickness of the weathered layer above the landslide was 2.15 m - 4.59 m with a Vp
value equal to 185 m / s. For the thickness of the weathered layer parallel to landslides is 0.80 m - 4.11 m with a Vp
value equal to 300 m / s and the thickness of the weathered layer perpendicular to landslides is 0.01 m - 2.35 m with a Vp
value equal to 300 m / s. Meanwhile, the bedrock layer under the weathered layer has Vp
of between 517 m / s to 1065 m / s in the form of sub-consolidated clay to very dense clay lithology.
Vessel Classifying and Trajectory Based on Automatic Identification System Data
Authors: Damastuti Natalia , Aisjah Aulia Siti , Masroeri Agoes
Published: October 2021

Nowadays, the development of the of Automatic Identification System (AIS) device has continuously increased. It was initially used to send information on the whereabouts of ships to avoid collisions, but with stored data, it is used for monitoring waters. Therefore, this study was carried out using AIS data to classify ships in Indonesian waters. Based on features such as length, width, and weight, it classified them into 9 types of vessels. The data mining process was used to characterize each type with the ensemble method. Furthermore, data processing was carried out to determine the ship’s trajectory pattern. In this study, 80% of training data was used while the rest were testing data. The results showed that an accuracy value of 99.8% was obtained with a Root Mean Square Error (RMSE) value of 0.12.
Preliminary result of electrical resistivity and electromagnetic methods to determine the bedrock
Authors: Paembonan Andri Yadi , Febriansanu Dicko Rizky , Huseina Angga Ahya , Sigalingging Asido Saputra , Nathania Edlyn Yoadan , Andika Putu Pradnya
Published: October 2021

Infrastructure development such as buildings, especially in multi-story buildings, really requires strong foundation support. In the construction of a multi-story building, usually using a pile that is embedded into a zone that has a hard rock arrangement or bedrock to support the building above it. This is a challenge for multistory buildings in areas of volcanic deposits or pyroclastic deposits. The rock layer below the surface in this area is dominated by less dense rocks such as tuff. This rock layer has more challenging when using for building foundations because it tends to be permeable, so a special method is needed to obtain information on hard rock or bedrock for building foundation needs. In other hand, the presence of weak zones, below the surface can cause sudden land subsidence which of course will damage the buildings on it. This study aims to determine the depth of the bedrock zone, in the pyroclastic deposit area using the integration of geophysical methods, resistivity and electromagnetic (EM) method. The resistivity method is more sensitive for areas that have large types of resistance or areas that are resistive, such as rocks that have low porosity and permeability such as igneous rocks. Meanwhile, the EM method is more sensitive in layers that have high porosity and permeability values or in conductive areas such as sediment layers. Nevertheless, the conductor layer is also influenced by the mineral content in the rock, so a good understanding of geology is needed in matching the data and conditions in the field. This is expected to be a reference in designing building structures, especially in pyroclastic deposit.
An Experiment of Determining Buried Channel Using ERP and IP
Authors: Paembonan Andri Yadi , Fattah Erlangga Ibrahim
Published: October 2021

Geophysical methods became an important technique for engineer since several decades. They have been used to study the engineering problem which has to be solved urgently. Detecting underground water channels is one of the most important issues in prevention and mitigation of water surge hazards in underground engineering. In this research, we use electrical resistivity profiling (ERP) and induced potential (IP) as the guide is proposed. By applying different configurations and varied electrode spacing, the water channel can be analysed by its resistivity and chargeability variation. The ERP method is sensitive to resistive layers which indicates the empty channel while IP can detect the presence of water. This is seen from both synthetic and measured data, where the resistivity of 60 Ω.m approximately implies that the channel is not filled with water, while in the area with moderate chargeability, ranging from 15 to 25 ms, indicates that water exists shrouding the channel. By understanding the known underground channel well, we can expand the study for other engineering problems and as references to apply the method in similar cases, such as the underground cavity which can be very important for infrastructure.
Petrophysics Evaluation for Determining Porosity of Shale Reservoirs
Authors: Hutami Harnanti Yogaputri , Winardhi Sonny , Priniarti Tiara Larasati , Handoyo  , Andara Muchammad , Christian Yoopy
Published: October 2021

Indonesia is known for its large potential of shale resources, yet the character of their physical properties remains unclear. This study focuses on how to assess the petrophysical properties of shale using conventional wireline logs. Shale has been largely known as a host rock producing hydrocarbon in the conventional petroleum system due to the amount of kerogen trapped during the depositional process. The kerogen or continuously called Total Organic Carbon (TOC) behaves like a porosity to a density log and this will be misleading to the higher porosity than the actual shale rock. Prior investigation evaluates the physical properties in shale rock, including shale porosity, TOC, and matrix mineralogy, at a certain limited depth. A solid rock is presumed to consist of a shale matrix and TOC. Meanwhile, shale porosity is contained only in water. TOC responses to sonic wave, density, and porosity logs. We calculated the experimental data to estimate the volume of TOC at the limited depth to obtain the correlation of available logs. Shale porosity is then computed using a density log with the TOC-influence removed. The results show that the shale porosity is to be TOC-free with a value range of 3-14%.
Authentication of Six Indonesian Ground Roasted Specialty Coffees According to Variety and Geographical Origin using NIR Spectroscopy with Integrating Sphere
Authors: Suhandy D , Yulia M
Published: October 2021

Several factors such as type of bean (Arabica or Robusta), geographical origin (elevation, soil type, temperature, and solar radiation), and agronomic/postharvest practices (fertilization, bean processing, fermentation, and type of roasting) have a great influence on the quality of final taste of the coffee. In this research, an authentication of six Indonesian ground roasted specialty coffees according to different in variety and geographical origin using NIR spectroscopy with integrating sphere was evaluated. A total of 70 coffee samples of Arabica and Robusta coffee from different geographical origins were used as samples. NIR spectral data in the range of 1175.79 nm to 1651.222 nm were obtained using a portable NIR spectrometer equipped with an integrating sphere. The unsupervised classification was performed using PCA and supervised classification was conducted using the SIMCA method. The result of PCA shows that the samples were well clustered according to variety and geographical origin along the PC1 and PC2 axis both using original and preprocessed spectra. The SIMCA performed good results both for original and preprocessed spectral data, most of the testing sample set were properly classified to their corresponding classes.
Chemical Compounds and Antioxidant Potential in Hot Water Extract of Cultivated Agarwood (Aquilaria malaccensis) Lamk Leaves
Authors: Batubara R. , Wirjosentono B , Siregar A H , Harahap U , Tamrin
Published: October 2021

Agarwood (Aquilaria malaccensis Lamk) leaves has potential as a source of antioxidants because in the hot water extract contains secondary metabolite compounds. This research aims to observe the chemical compounds and antioxidant potential in hot water extract of cultivated agarwood leaves. Agarwood leaves are processed into simplicia, and extracted with hot water. Several tests conducted in this research, including phytochemical screening in order to observe the chemical compounds in hot water extract of agarwood leaves; GC-MS test to observe the chemical constituents, and DPPH method to observe the antioxidant activity. Agarwood leaves hot water extract positively contained of flavonoid, triterpenoid, tannin and glycoside compounds. The identification result of agarwood leaves hot water extract using GC-MS test showed 9 compounds, they are Undecane, Benzene 1.3-dichloro-2-methoxy-, 1.alpha.- (Angeloxy)-6.beta-(isobutyroxy)-9-oxo-10.alpha.Hfuranoeremophilane, Methyl (6-Methyl-3-pyridazinyl) Ketone, 1-Heptyl-1H-(1,2,3)-triazole-N-{[2′-(hydroxyethoxy)ethylamino] ethyl}-4-carboxamide, 1-Heptyl-1H-(1,2,3)-triazole-N-{[2′-(hydroxyethoxy)ethylamino]ethyl}-4-carboxamide, Borane. [2-(dimethylphenylsilyl)-1-, ethyl-1-propenyl]diethyl-, (E)-, Hexadecanoic acid, methyl ester, and 1-Phenyl-5,5-dimethyl-4,6-dioxa-5-sila-8-nitrooct-1-ene. The antioxidant activity of agarwood leaves hot water extract is categorized as the very strong antioxidant activity.
Pitch angle control of a wind turbine using fuzzy logic control
Authors: Santoso Dian Budhi , Pangestu Adam Bagus , Latifa Ulinuha , Fauzi Ahmad , Zahro Latifa
Published: October 2021

Electricity is one of the primary needs, so we can be sure that the need for electricity for the Indonesian people is very large. This causes the need for development in empowering new and renewable energy power plants, one of which is wind turbines. Currently, technological developments are increasingly advanced, by following existing technological developments, a wind turbine must have more modern controls to make it easier to control the electrical power output generated by wind turbines. In this research control wind turbine blades using pitch angle with fuzzy logic control method, where this control will focus on adjusting the wind turbine blades because the performance coefficient of the wind turbine is very dependent on the wind turbine pitch angle. The fuzzy control is set to be able to maintain the stability of the wind turbine power output at 20KW, it is evident from the simulation results obtained with an average difference of only 0.77%.
The Application of Tactical Urbanism in Public Space on COVID-19 Transmission Prevention
Authors: Pradifta Fachmy Sugih , Puspitasari Gina , Indratno Imam , Fadhilah Faisal
Published: October 2021

Tactical urbanism (TU) is frequently used as an interim or low-cost solution to tackle a design-related problem in public space. As the importance of good-designed public open space for mental health now realized significantly during the pandemic, the need for a tool to keep health protocol followed in public space is imperative. The modification of public spaces is applied in several cases to guide people’s behaviour and interaction within public space under health protocol submission. This paper tried to analyse the application of TU to combat COVID-19 transmission on public space by using case study and systematic literature review from applied cases worldwide. The cases are categorized based on the problem identification and interventions conducted on urban design elements. It is found that the application of TU can be assembled into health protocol requirements-driven and accommodation of COVID-19-related policies externalities. The outcome of this paper could be used as an issue-based urban design precedent on COVID-19-related tactical urbanism interventions.
Study of Cultural Landscape Character in Pekon Hujung, Lampung Barat
Authors: Pratiwi R A , Nabilah R , Wijayanti G M
Published: October 2021

Lampung is a province on Sumatra Island, which has a variety of traditional settlement characteristics. One of the traditional settlements in Lampung is Pekon Hujung or “Ujung village”, located in Belalau District, West Lampung Regency. The houses in Pekon Hujung are still built from local wood materials and are referred to as ‘lamban’. Urban development that occurs quickly can shift the cultural values that exist in traditional settlement and its environment. Development will inevitably have an impact on the environment, both having a positive impact and a negative impact. One of the possible negative impacts is the loss of values and cultural characteristics that are unique to a traditional settlement area. This research was directed to identify the landscape elements that formed the landscape character so ita can be used to determine the right conservation actions. This research was conducted using the Landscape Character Assessment (LCA) approach to identify and to describe the elements and unique characteristics that formed the landscape. LCA method also can be used to make a significant contribution to environmental protection and sustainable development. The result shows that Pekon Hujung cultural landscape, as a traditional settlement is formed and depended on its natural resources and environment. Pekon Hujung still maintains tradition and culture in the form of settlement and the people activities.
Antagonistic activity screening of Bacillus siamensisLDR against fungal associated with crop contamination
Authors: Pertiwi M , Santoso I , Fadhilah Q G
Published: October 2021

Bacillus spp. are potential biocontrol agent that commonly used to reduce contamination on crop caused by microorganism, especially fungi. The purpose of this research is to investigate the antagonistic activity of B. siamensis LDR towards fungal crop contaminant (Aspergillus flavus AHM, Aspergillus clavatus ABH, and Aspergillus tamarii KCP). Antagonist assay was conducted using the dual culture method, streak and pour plate technique. The streak technique showed B. siamensis LDR can inhibit the A. flavus AHM, A. clavatus ABH, and A. tamarii KCP with percent inhibition of 42.75 %, 58.89 %, and 28.46 %, respectively. Meanwhile, the pour plate technique represented higher percent inhibition of A. flavus AHM, A. clavatus ABH, and A. tamarii KCP, 89.28 %, 87.32 %, and 66.35 %, respectively.
Pore type-based carbonate reservoir characterization using rock physics modeling of “RF” field North Sumatera Basin
Authors: Harahap R F , Riyanto A , Haidar M W
Published: October 2021

Heterogeneity and Complexity are the main reasons why carbonate reservoirs offer a great challenge for its characterization compared to siliciclastic reservoirs. Carbonate reservoirs are known for its variable pore type and this variability can affect the Vp value up to 40 %. Pore type can vary depending on its depositional environment and diagenetic processes and these pore types are highly correlated with permeability. Differential Effective Medium is used to model the elastic modulus of effective medium that takes into account the effect of complexity of rock pore type. This complexity, in modeling, is divided into three geophysical pore types, which are stiff pore, interparticle pore, and microcrack. The resulting rock physics model is then used to calculate the value of Vs. Pore type inversion shows that the dominant pore types in this study area are interparticle and microcrack. The results of 1D modeling are then distributed to seismic volume to map the spatial distribution of pore type. Sensitivity analysis shows that acoustic impedance, shear impedance, and porosity have a good correlation with pore type. Therefore, Probabilistic Neural Network is used to distribute 1D pore type to seismic volume by using acoustic impedance, shear impedance, and porosity as a training data. The resulting volume is then used to interpret the zones with best permeability
Residential relocation for landslide prone residences in the upper Ciujung watershed
Authors: Arbenta R , Marko K
Published: October 2021

Lebak Regency, which is in Banten Province, is an area in Indonesia that has many years affected by the landslide disaster. Banten Province itself is a disaster-prone area. In Indonesia, Banten Province is a province with a fairly high hazard rating according to BNPB in the Indonesian Disaster-Prone Index book. Landslide disasters often occur in regions of Indonesia that have diverse topographies. Landslides can cause various kinds of losses like physically, socially, and economically. In early 2020, Lebak Regency experienced flash floods which leads to many residential areas especially areas on the upper ciujung watershed to be affected by landslide. From this disaster that happened on 1st January 2020 alone, 20 bridges were damaged in the 6 affected sub-districts. The analysis in this study used the Spatial Multi-Criteria Evaluation (SMCE) method and an overlay. This study aims to produce locations which have the potential to be relocation areas for landslide prone residences in the Upper Ciujung Watershed which includes 5 district, Cipanas District, Lebakgedong District, Sajira District, Muncang District, and Sobang District. From this research, it was found that areas that have the potential to be the location of residential relocation are only in 4 of the sub-districts within the research areas with a total area of 88.12 Ha which is in the eastern part of Cipanas District, southeast of Lebakgedong District, and also in the western part of Muncang District.
Effect of different red palm oil volume on characteristics and degradation of polylactic acid/zinc oxide film
Authors: Karim S F A , Jai J , Saiful N A , Hamid K H K , Kamarudin N
Published: October 2021

PLA/ZnO combination caused agglomeration, especially at a high concentration of ZnO. This condition improved by adding a plasticizer to smoothen the incorporation of ZnO into PLA. The work’s objective was to study the changes in polylactic acid/zinc oxide (PLA/ZnO) film’s properties incorporated with red palm oil (RPO) that acted as a plasticizer. The films were prepared using the solvent casting method. RPO’s impact as a plasticizer was determined on the film’s thickness, moisture content, functional group, mechanical properties, and solubility. More RPO increased the thickness because of the formation of more free volume in the polymer matrix. Otherwise, the moisture content has shown a different trend, which decreased with more RPO content. Fourier transform infrared spectroscopy proved that interaction occurred between each material in this film by sharpening the peak representing the ester group, C = O stretching bonds, 1365 cm−1(C-H bending), and 1216 cm−1(C-O stretching). The highest tensile strength obtained by PLA/ZnO/0.25RPO, showing the lowest performance in elongation at break. ZnO increased the solubility of PLA film, but the presence of RPO proportionally reduced the solubility. These results counsel that the PLA/ZnO/RPO films could be applied as an alternative to manufacture film packaging that needs high tensile strength and low elongation at break. Further study should be conducted for a range of one until 25 weight % of RPO over 100% PLA to determine the optimum formulation.
Three-Phase Induction Motor Controller Design Based on Hysteresis Voltage Control
Authors: Ismail @ Marzuki M S N , Arifin A I M , Chek W A K W , Hussian A H , Tazudin F R M , Zulkifli S A
Published: October 2021

This paper describes a controller for Three-Phase Induction Motor. Induction motor is an electromechanical actuator widely used due to its reliability and relatively low maintenance cost. However, the control problem of an induction motor is complex due to nonlinearities, load torque perturbation, and parameter uncertainties. An element included in this study is voltage source control, which is to control the voltage fed from three-phase inverter to Three-Phase Induction Motor. Hysteresis Controller was proposed in this paper to minimize voltage error. Hysteresis controller is seen as an input – output phase lag corrector. The implementation of the designed hysteresis controller is performed in simulation using MATLAB/Simulink. The result proved that the proposed controller design can minimize the line voltage error of the induction motor, preventing the line voltage from being kept low hence avoiding excess current at low speeds.
A Study on Different Slot Position for Designing Dual Band Microstrip Antenna for 5G Wireless Communication
Authors: Nasir N A M , Ja’afar H , Baba H , Aziz N H A
Published: October 2021

In this paper, four antenna designs with different slot positions for dual band frequencies are analysed. A reference antenna operating at 8 GHz is used at a dimension of 30 mm2 using Rogers RT58880 as the substrate with a dielectric constant of 2.2. Two slots are etched in order to produce a dual band. The antenna resonates at 8 GHz and 15 GHz. Return loss at 8 GHz and 15 GHz are −17.03 dB and −21.37 dB with gain at 7.39 dB at 8 GHz. By using CST Microwave Software, the simulated results are obtained. The slotted antenna produces a dual band antenna that is a suitable candidate for 5G wireless communication tool.
High Selectivity Hydrogen Gas Sensor Using Pd/ZnO Tapered Optical Fiber
Authors: Yahya N A M , Hamid M R Y , Ong B H , Mahdi M A , Yaacob M H
Published: October 2021

Besides so many great potentials of hydrogen (H2) applications, such as primary reagent used for the industrial chemical processes and a potential clean energy source in future, handling it can cause potential hazardous situations due to its highly flammable and explosive nature. Therefore, hydrogen leakage detection is crucial to control the chemical reaction process running smoothly, thereby ensure industrial manufacturing safety in routine life. For this reason, this paper will be reported on tapered optical fiber coated with Pd/ZnO that is sensitive and highly selective towards H2 gas. The sensor developed comprises a tapered optical fiber and ZnO nanoparticles incorporated using a chemical bath deposition technique. The synthesized ZnO was inspected by FESEM, RAMAN, TGA and UV-VIS to confirm its material properties. The sensing response towards H2, CH4 and NH3 was conducted to observe its sensitivity and selectivity towards the gases. It was found that the Pd/ZnO tapered optical fiber sensor demonstrated high selectivity and sensitivity on H2 gas compared to CH4 and NH3 with 86.6% increment of response. The repeatability test was also conducted to re-confirm the reliability of the sensor developed. The test measured standard deviation of the number of cycles repeated which yield 0.02902 or 97.1% to produce the same output or responses. These results perhaps are useful, especially in the automotive industry for advanced combustion monitoring and emission control.
Design and Fabrication of Kayak Carrier
Authors: Ghazali H , Mas’aud N H , Rahman N A
Published: October 2021

Kayak has become the most popular outdoor activities among the community of UiTM Cawangan Terengganu, Kampus Bukit Besi. It is due to the location of this campus is situated near Tasik Puteri. During kayak activities, the users need to bring the kayak from campus to the lake. The distance from the storage area to the lake is about 800 m. A minimum of two persons is required to carry the kayak due to its size and weight. Where the average recreational kayak weighs 16kg for a single kayak and 27kg for a tandem kayak. Therefore, this study is focused on designing the kayak carrier to overcome these problems. There are several stages involved in producing the kayak carrier, which are concept generation and evaluation, CAD design, fabrication, and testing. In a conclusion, by using this kayak carrier, only one person needed to carry the kayak from the storage area to the lake, and the traveling time also can be reduced as the person need to cycle instead of walking.
Piper Nigrum (Green Corrosion Inhibitor) as a Modified Quenchant in Heat Treatment of Ductile Iron
Authors: Idham M F , Nasip S H , Hazirah N , Abdullah B , Alias S K
Published: October 2021

Corrosion of ductile iron leads to many consequences in all its application aspects, like a structural failure due to the porosity formation, which is consequenced by corrosive chemical exposure. Hence, this project was carried out to modify the water quenchant using Piper Nigrum (black pepper) essence, as a green corrosion inhibitor, in promoting corrosion resistance towards austenitized ductile iron in hydrochloric acid (HCl). Furthermore, its effects on the hardness and microstructure of austenitized ductile iron were also investigated. The modified quenchant employed in the austenitizing process was modified by diluting Piper Nigrum extract to several concentrations. The corrosion resistance performance of ductile iron quenched by this modified quenchant was tested using the gravimetric method. The samples were exposed to 1 molar (M) of HCl for 2 hours in the method. This study’s novelty has proved that the Piper Nigrum extract was successfully used as an alternative quenchant to reduce ductile iron’s corrosion rate in HCl and its corrosion resistance performance was equipotential to other synthetic inhibitors practiced conventionally. This approach could replace the use of synthetic inhibitor, which is harmful and costly. The gravimetric test showed that the corrosion rate of austenitized ductile iron decreased to 51.2685 mm/year and inhibition efficiency increased to 72.17% as the extract’s concentration of quenchant increased to 15%. This extract’s presence as a quenchant in the heat treatment process neither improved nor exacerbated the samples’ mechanical properties, and it has not changed the behavior of microstructure transformation.
A smart building security system with intelligent face detection and recognition
Authors: Khairuddin M H , Shahbudin S , Kassim M
Published: October 2021

The security system is the most important application that protects several threats from inside and outside of an organization. The purposes of several security building applications such as the system will know criminals, disgruntled former employees enter the workplace, and enabling building security to work proactively for ensuring that associates and customers are safe from harm. By implementing face detection and recognition of the security system, video surveillance in the building can be improved by upgrading the system of video surveillance with artificial intelligence. The aim of the research is to develop the face detection and recognition in the security system in the building with recognizing human faces and image capture to the cloud storage. The result shows that the video will stream and recognize human faces whether the person is authorized or unauthorized in the system image using Raspberry Pi 3. For analysis purpose, the image captured and stored from the two type of cloud storage namely Cloudinary and Dropbox had been analyzed. Based on the analysis, the image captured and stored into Dropbox cloud storage give the best performance features which gained more 75% of quality images.
Extending technology acceptance model (TAM) to measure the students’ acceptance of using digital tools during open and distance learning (ODL)
Authors: Noh N H M , Raju R , Eri Z D , Ishak S N H
Published: October 2021

Ever since the Covid-19 pandemic outbreak, we are taught to live in the new norm. Higher learning institutions are forced to adopt a new norm of open and distance learning (ODL) immediately. Since that, students are facing issues, especially in courses that need a conventional setting. During ODL, students and lecturers rely on digital tools, social media, pre-recorded video, and video conference to assist the learning process. However, there are unexplored topics on the students’ intention to use digital tools during ODL. A sample of 367 students who responded from different diploma and degree programs of Universiti Teknologi MARA (UiTM) Terengganu was collected via an online survey. Data collected are analysed on its correlation and coefficient determinant, regression, and analysis of actual use. Technology Acceptance Model (TAM) is expanded to include external factors of technology access and online learning skills to be measured with perceived usefulness, perceived ease of use, attitude, behaviour intention to use and actual system use. Findings on the study will help uncover significant understanding of students’ acceptance of ODL in using digital tools for a better decision-making and students’ support assistance. Hence, this study benefits us to foresee the possible future need for courses in conducting ODL successfully.
Designing Roller Coaster Loop’s By Using Extended Uniform Cubic B-Spline
Authors: Sukri N M , Nor-Al-Din S M , Razali N K , Mazwin M A A
Published: October 2021

Roller coaster is one of the attractions to the public. The design of roller coaster plays an important role for the smoothness and safety of each roller coaster rail. This research is about designing a smooth roller coaster rail loop using extended cubic uniform B-spline method as one of the alternative in designing a smooth roller coaster rail. Two-dimensional design of roller coaster rail loop is form by using extended cubic uniform B-spline with degree 3, 4 and 5 and shape parameter, λ= 0.5, and 1. Then, three-dimensional cubic B-spline is formed by using sweep surface which is translation method. The loop is analysed by the distance between curve and control polygon. Moreover, the G-felt with the different radius of the loop has been calculated. The value of G-felt for each method used will be compared to the G-felt value of the original roller coaster. The result from this research showed that by using extended cubic B-spline method degree 4, λ = 0.5 is the best way to design roller coaster rail because it has the best G-force value compared to others designs.
Detection of Myristic and Palmitic Acid in Butter By Hydrolysis And Acid Methylation
Authors: Tapak N S , Senin S , Mohamed A H , Dzulkifli N N , Zain Z M , Ahmad N M
Published: October 2021

Myristic acid and palmitic acid in butter was successfully detected by Gas Chromatography Flame Ionization Detector (GC-FID) after hydrolysis and methylated to fatty acid methyl esters (FAMEs). Optimization of initial oven temperature and carrier gas flow rate were determined earlier, and it was found that 50°C and 2.0 mL/min were chosen as optimum initial oven temperature and carrier gas flow rate respectively. Two different calibration curves were constructed using methyl myristate and methyl palmitate. Both were found linear at 20-100 ppm with correlation coefficient (R2) 0.9972 and 0.9933 respectively. Methyl stearate were used as an internal standard (IS). Limit of detection (LOD) where the lowest concentration that can be detected by the instrument was found at 16 ppm. In order to determine the concentration of FAMEs in butter, fatty acids were hydrolyzed using lipase enzymes and were converted to FAMEs by acid catalyst methylation method. Butter with Brand A, B and C was found to contain 24 ppm, 21 ppm and 30 ppm Methyl Myristate. Methyl Palmitate was only found in butter Brand B and not detected for another two brands.
Lithology Identification, Shale Volume Estimation and Formation Wate Saturation of Fenchuganj Gas Field Using Wireline Log Data
Authors: Rahman M , Mojid M R , Khan I M
Published: October 2021

This study has been undertaken with a view to interpreting and analyzing different types of logs, detecting hydrocarbon-bearing sand zone, identifying the lithology, estimating shale volume, and determining water saturation of the formation of the Fenchuganj gas field. Fenchuganj gas field is in the southern part of Bangladesh in the Sylhet division. It lies in the Surma basin and characterized as a water drive gas field. Gamma Ray (GR) log and Spontaneous Potential (SP) log analysis help to interpret the formation lithology. After interpreting lithology, the gamma-ray log and SP log were analyzed further, and the hydrocarbon-bearing zone was detected. From the analysis of different logs, for well 4, so many gas-bearing sand zones have been detected. The gas-bearing zones are found between (1585-1595) m, (1600-1610) m, (2409-2420) m, (2265-2270) m, (2295-2303) m, (2435-2450) m, (2465-2480) m, (3150-3155) m, (2955- 2960) m. These are the gas-bearing zones of fenchugonj well-4 determined from the composite log of this field. Water-bearing sand zones are between (1708-1714) m and the fully compacted shale zone is between (1920-1930) m. From the analysis of different logs, for well 5, so many gas-bearing sand zones have been detected. The gas-bearing zones are found between (2365-2385.5) m, (1820-1830) m, (1782-1803) m, (305-308) m, (336.5-338.5) m, (607.5-609.5) m. These are the gas-bearing zone of fenchugonj well-5 determined from the composite log of the field. Shale volume has been estimated from the gamma-ray log and from resistivity logs by the true resistivity method. In well 4, the calculated value of shale volume by Gamma Ray method and true Resistivity methods were respectively 15% and 6%, in well 5 these values were 7.25% and 7.64%. Formation water resistivity was determined from the formula and taken as 0. 1ohm-m and mud filtrate resistivity 0.76 ohm-m. for well-4 and for well-5 it was taken as 0.7 ohm-m (from the provided composite log of well 4 and 5). Formation true resistivity Rt was estimated directly from the ILD log and true resistivity log. The average value of Rt for well-5 was 33.75 ohm-m and for well-4 the value is 34.09 ohm-m. From the RFOC log, flushed zone resistivity Rxo was calculated directly. Water saturation has been determined by three different techniques named Archie, Indonesia, and Simandoux method. For well 5, the value of average water saturation found from Archie, Indonesia, and Simandoux model was 8.5%,22%, and 24.84%, and for well-4. The value of average water saturation was found as 7.3%,18%, 20.51%respectively.
Eco-Friendly Hybrid Solar Cells using Eugenia Claviflora as New Alternatives Sensitizer to TiO2/PEDOT:PSS
Authors: Kamarulzaman N H , Salleh H , Dagang A N , Ghazali M S M , Ishak N , Abdullah M , Muda S M
Published: October 2021

Studies on HSCs have been focussing on exploration of natural dyes obtained from Eugenia claviflora (EC). This work mainly aimed to enhance device efficiencies related to new dye sensitizer particularly Eugenia claviflora. These samples were then characterised based on morphology, thickness, optical absorption, electrical conductivity and solar cell’s performance in term of efficiency, voltage and current using various techniques including FESEM, EDS, profilometer, UV-Vis, FTIR and autolab with irradiance of 100 mW/m2. TiO2/PEDOT:PSS/ EC obtained an open – circuit voltage (Voc) of 0.43 V with fill factor of 0.2 leading to an efficiency of 1.33%. The absorption of TiO2/PEDOT:PSS/EC was located at 550 nm (between 450 nm to 755 nm) which exhibited an intense broad band in visible light. Hence, fabrication of HSCs was successful thus improving its’ performance.
Electron–phonon interaction and superconductivity in hexagonal ternary carbides Nb2
AC (A: Al, S, Ge, As and Sn)
Authors: Karaca E , Byrne P J P , Hasnip P J , Tütüncü H M , Probert M I J
Published: October 2021

The superconducting transition temperatures T
c of hexagonal Nb2
AC (A: Al, S, Ge, As and Sn) are investigated using density functional perturbation theory to model the electron–phonon interaction. A critical assessment of the calculated electronic structure and density of states revealed that the electronic states near to the Fermi level are mostly composed of the Nb 4d states, which are responsible for the electrical conductivity. The theoretical T
c data from electron–phonon calculations are in excellent agreement with the Fröhlich model, and this model was used as a computationally efficient screening method to identify promising Nb–C M
2
AX phase materials. For Nb2
AC (A: Zn, Cd, Al, Ga, In, Tl, Si, Pb and P), the model indicated that Nb2AlC should have the highest T
c of this set, a little lower than Nb2GeC and comparable to Nb2SC and Nb2SnC. Superconductivity in Nb2AlC has not been studied experimentally, but this result was confirmed by full electron–phonon calculations, which also revealed that the mechanism for superconductivity is the interactions of Nb 4d-state electrons with low-frequency phonons (in particular, acoustic phonon and low-frequency optical phonons dominated by Nb and the A element). The average electron–phonon coupling parameter was found to be λ ∼ 0.646, 0.739, 0.685, 0.440 and 0.614 for Nb2
AC (A: Al, S, Ge, As and Sn), respectively, with a corresponding superconducting critical temperature T
c ∼ 6.7 K, 7.7 K, 9.8 K, 2.1 K and 6.3 K, respectively.
Anti-symplectic involutions on rational symplectic 4-manifolds
Authors: Kharlamov V. , Shevchishin V.
Published: October 2021

This is an expanded version of the talk given by the first author at the conference “Topology, Geometry, and Dynamics: Rokhlin – 100”. The purpose of this talk was to explain our current results on the classification of rational symplectic 4-manifolds equipped with an anti-symplectic involution. A detailed exposition will appear elsewhere.