bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Polyaniline content on the capacitance of Polyaniline/Carbon powder composite
Authors: Rattanaveeranon Santi , Asanithi Piyapong
Published: December 2019

Developing capacitor with high capacitance and power capacity has received much attention in the scientific research. This research aimed to study the effect of polyaniline (PANI) content on the capacitance of the capacitor fabricated from PANI/carbon powder composites. Wasted-sweet potato was used as the source of carbon for synthesizing carbon powder (CP). Two types of CP were considered in the study, including with and without sulfuric acid pre-treatment. For CP without acid treatment, the sweet potato was heated at 900 °C for 2 h in argon atmosphere. For CP with acid treatment, the sweet potato was reacted with concentrated sulfuric acid for 2 h and then heated at 900 °C for 2 h in argon atmosphere. Both samples were ground before use. PANI contents of 0-5 %wt were used to combine with the CP samples. SEM, FTIR and potentiostat/galvanostat, respectively, investigated the physical, chemical and electrochemical properties of the composites. The electrochemical results showed that 5 %wt PANI composited with acid-treated CP provided the highest specific capacitance of 304.87 F/g. This composite also showed high stability under charge-discharge investigation. This study confirms that carbon powder synthesized from wasted-sweet potato composited with PANI can be useful for developing supercapacitor.
Light curve analysis of a transitional millisecond pulsar PSR J1023+0038 with Kepler K2 mission
Authors: Nilarat C , Jaroenjittichai P , Jaroenjittichai A P
Published: December 2019

PSR J1023+0038 has been known as a transitional pulsar-low-mass-X-ray binary (LMXB) system, which provides crucial information in understanding the evolution of pulsars in binary systems. We report analysis of 80-day continuous optical light curve of PSR J1023+0038 with the Kepler observations during K2 mission. The light curve was observed from May to August 2017, where the system appeared to be in its LMXB state. At ∼30 minutes time resolution, the data were fitted with a Gaussian window function, which generated a smoothed light curve with 100, 000 from 3545 raw data input. The time at the maxima and minima of the light curve was measured and compared with the orbit ephemeris predicted from a quadratic polynomial function published by previous work. We found that at MJD ∼57935 there appeared to be a constant delay of ∼1.06 hr added to the orbit, which then gradually recovered to the expected period at MJD ∼57965. Possible causes have been proposed to explain such delay includes a third body involvement or hot spots on the star.
Microstructure and electrochemical study of equal channel angular pressed Al-Zn alloys
Authors: Khamnantha P , Linjee S , Palsson N S , Banjongprasert C
Published: December 2019

This research focuses on the effect of severe plastic deformation (SPD) on microstructure and properties of Al and Al-Zn (in 1, 2, 3, 4, 5 wt%) anodes of Al-air battery. The Al-Zn alloys with a diameter of 12.5 mm and 62.5 mm long were pressed in an ECAP die (press angle $=90°, XP=20°), using route Bc with 2, 4, 6, 8 passes at room temperature. Microstructural characterization was carried out using scanning electron microscope (SEM). The cast samples were solutionized at 450 °C for 1 hr after pressing. Grain size of the as-ECAP samples decreased with an increase of ECAP passes. The smaller grain size resulted in strengthening of Al-Zn. An decrease in grain size was due to significant change in the microstructure from an intensive shear stress after ECAP. Polarization test in a 3.5wt% NaCl solution were used to study electrochemical behaviours of the as-cast and ECAP Al-Zn alloys. The conclusion from the research will be used as a platform to develop Al anodes for Al-air battery in the future.
Play dough circuits: a tangible and friendly medium for understanding physics
Authors: Wuttiprom S , Wuttisela K , Khlongkhlaew K
Published: December 2019

Students consider that physics is difficult because of its abstract nature and the involvement of mathematics. One of the most difficult topics is a simple direct current circuit. Physics education research shows that students learn better when they construct their own understanding of scientific ideas within the framework of their existing knowledge. To accomplish this process, students must be motivated to engage with the content actively and be able to learn from that engagement. The purpose of this research was to compare the grade 6 students’ understanding of the scientific concept of simple direct circuits before and after participating in a STEM activity that involved the building of circuits from play dough. Twenty questions from the Interpreting Resistive Electric Circuit Concepts Test were selected to evaluate students’ reasoning regarding direct current resistive electric circuits. Findings revealed that the students’ scores working with the different conditions after learning were significantly higher than they were before learning. However, analysis on learning progress showed that the group that had to create more works had higher normalized gain than the group that created less works. When the work was analysed with rubric criteria, it illustrated that more conditions caused more complexity and diversity to the work. In short, the condition or situation set to students affected work creation.
Design of radiation shielding for the 4-MeV RF linac using the Monte Carlo simulation
Authors: Jaikaew P , Rimjeam S
Published: December 2019

A radio-frequency (RF) linear accelerator (linac) and related system for irradiation of electron beam on natural rubber is under the commissioning at the PBP-CMU Electron Linac Laboratory, Chiang Mai University. The maximum kinetic energy of electron beam that can be achieved from the accelerator is about 4 MeV. The bremsstrahlung radiation in the x-ray regime is produced when electrons interact with materials in the beam path. The radiation with the dose exceeding the regulation limit can be harmful for the personnel in the laboratory and public area. This research concentrates on design of radiation shielding to prevent the leakage of radiation from the accelerator area. Calculation of the photon’s energy deposition per volume due to the interactions of electron beam with materials in the irradiation system and surrounding area including the collision and bremsstrahlung processes was performed by using a Monte Carlo simulation software GEANT4. Shielding walls of the 4-MeV linac and its irradiation system consists of iron plates with the thickness of 2 cm for the side walls and 3 cm for the top wall. Results of the radiation calculation suggested that the photon’s energy deposition per volume outside the accelerator hall reduces by more than 99.5% after the shielding walls were added.
Design and test of DC motor drive system for agriculture electric vehicle
Authors: Pornharuthai P , Kuna P , Sukson S , Ekthammathat N
Published: December 2019

This research has been design a 1-seat agriculture electric vehicle modified from ATV using by DC motor 48 V 1, 000 watts. This electric vehicle has 4 batteries of 12 V 40 AH for power source. The size of the vehicle is 0.785 × 1.20 × 0.815 m, weight of about 152 kilograms. The performance test of theagriculture electric vehicle shows that the maximum speed can be achieved at average of 41.5 kilometres per hour, test by people weighting 60 kilogram. The average times for accelerated from 0-20, 0-30 and 0-40 kilometres per hour are 2.66, 4.67 and 5.84 seconds, respectively. The operating time of the electric vehicle can be used at the average of 30.50 minutes; running at an average distance of 13 kilometres with charged battery takes an average 29.88 minutes.
Biological hydrogen production from biomass at room temperature
Authors: Kodtharin N , Chanonmuang P , Tipparach U
Published: December 2019

Hydrogen is an environmentally friendly source of renewable energy and it has a high energy yield greater than hydrocarbon fuels. In this work, we present the production of hydrogen gas by dark fermentation, a biological process. The substrate was cassava starch. The sources of hydrogen producing bacteria, Clostridium, were swine manure and buffalo dung. The inoculum sludge was pre-heated treatment at 100 °C for 2 hours. The fermented hydrogen gas can be produced at room temperature. The cassava starch concentration was 100 g/l. The maximum hydrogen yield of 80 ml hydrogen gas per gram of starch was achieved. The highest purity of hydrogen was 37% when fermented volume was 120 ml at 144 hours. Besides hydrogen gas, the product contained several undesired-impurity gases including methane, carbon dioxide, hydrogen sulphides, and water vapour.
The effect of low-pressure plasma treatment on sunflower seed germination and sprouts growth rate
Authors: Lonlua R , Sarapirom S
Published: December 2019

This study presents the influence of low-pressure plasma treatment on germination behaviour of sunflower seeds (Helianthus annuus). Both peeled and unpeeled seeds were treated with Ar plasma. The plasma was characterized using OES for understanding of physical and chemical species in the plasma. The physical properties and chemical properties of the samples were studied using SEM and water contact angle. Growth parameters including water uptake, seed germination, sprouts length and dry weight were also investigated. It was found that the surface roughness increased with the plasma-generating power. The water absorption decreased when the power increased and super hydrophilicity was achieved at a 100 W. The water uptake rate showed highest at 150 W plasma power. The highest rate of seed germination was found when the sunflower seeds were treated with plasma power of 150 W at 5-day sowing. Sprout length and dry weight increased with the plasma power as well. In summary, sunflower seeds treated by Ar plasma could improve seed germination rate, leading to significant change in wettability and growth parameter.
Crustal density structure across Thailand delineated from 2D density modelling using gravity data and receiver function
Authors: Nornin N , Noisagool S , Siripunvaraporn W , Amatyakul P
Published: December 2019

This work aims to gather geological and geophysical evidences to construct the crustal density model of Thailand. The initial density models beneath 14-, 16- and 17-degree latitude were delineated from receiver function (RF) data and global crustal density model. The crustal density models were then updated to fit the Bouguer gravity anomaly data (BA) provided by the Royal Thai Survey Department using a 2-D gravity modelling software. The upward continuation technique was also applied to BA for enhancing the deep structure by omitting the influence of shallow structures. The derived crustal density models agree with Thailand’s tectonic setting. The density of the upper crust increases from 2.60 to 2.64 g/cm3 from west to east, from Sibumasu to Khorat Plateau – Indochina terrane. Between these two main terranes, the obtained model reveals the back-arc island, Sukhothai arc and Inthanon Zone, with a density of 2.55 g/cm3. The higher density of the lower crust with the derived mantle boundary from RF, ranging from 30.8 km of Sibumasu in the western to 38 km in the Khorat Plateau – Indochina terrane in the east, fit well with the filtered BA. Low BA that appear in Khorat plateau is not associated with topography in area which correspond to the high-density structure above upper mantle which need further investigation. Although, the developed crustal density models agree with BA, RF and tectonic evolution of Thailand, the additional gravity survey is suggested to enhance the crustal density models along the selected profiles.
Benchmarking of GPU-based pulsar processing pipeline of 40-m Thai national radio telescope
Authors: Thongmeearkom Tinn , Jaroenjittichai Phrudth , Scragg Thomas , Walker Charlie , Breton Rene , Stappers Ben
Published: December 2019

In recent years, Graphics Processing Unit (GPU) have been widely used in several astronomical applications. The 40-m Thai National Radio telescope (TNRT) is under construction in Chiang Mai, Thailand. We conducted benchmarking of the pulsar processing software to evaluate the capabilities of a computer with Xeon E5-2630 and GPU GTX1080Ti. The pulsar software DSPSR was used to simulate raw baseband data, coherently de-disperse the data and generate a folded time-frequency-domain pulse profile. We experimented with combinations of bandwidth, the size of the sub-bands, a range of dispersion measure (DM) values, and parallel instances of DSPSR jobs. The result shows the processing time increases with higher values of bandwidth DM as expected. However, the processing time appears to decrease with the size of the sub-bands, that at the same total bandwidth the processing with 1.5625 MHz/channel is faster than those with 3.125, 6.25 and 12.5 MHz/channel by approximately 10, 25 and 50 percent, respectively. This indicates that the processing in DSPSR is best when the channel resolution is high, however, further investigation is needed to determine the highest optimal value. We also consider parallel processing and to this, one, two and four identical scripts were simultaneously executed in parallel, where we found that single job is six times faster than four simultaneous jobs. In principle, parallel computing is expected to be more efficient, however, this can be explored further to find the actual bottleneck in the pipeline and hardware.
Timing noise of 133 pulsars in the southern hemisphere
Authors: Namkham N , Jaroenjittichai P , Johnston S
Published: December 2019

Pulsars are small, dense stars which rotate up to 1500 times per second and emit radio waves in a directed beam along their magnetic axis. Pulsars are remarkably stable rotators, and by measuring the arrival times of the radio beam the pulsar can be used as a clock in space. Applications of pulsar timing have led to the first exoplanet system, stringent tests of theories of gravity and have the potential to detect gravitational waves. Yet, the pulsars spin is not perfect, and understanding the imperfections (timing noise) is important to the aforementioned applications. Here, we present the analyses of timing noise of 133 pulsars observed with the Parkes radio telescope in Australia over the period of 4 years. The results show that as consistent with pulsar toy model equations the measured breaking index, representing the magnitude of timing noise, has an anti-correlation with the spin-down rate, spin-down energy and characteristics magnetic fields, and it also has a positive correlation with the characteristics age at significant of 10σ. The error in the slope values of those relationships are in the order of 9 percent, which may imply imperfections of the pulsar toy model.
Stable isotopes relationship between precipitation and surface water, Phitsanulok
Authors: Kulsawat W , Nochit P
Published: December 2019

The stable isotope technique provides an effective way of identifying the basic hydrological processes and evaporation in the area. In this paper, the objectives were to investigate of the isotopic characteristics of the precipitation and surface water and to estimate the water evaporation loss from Yom River in the Chumsaeng Songkhram sub-district, Phitsanulok province for 2 years during 2016-2017. Results shown that the Local Meteoric Water Line (LMWL) was defined as δ2H = 7.346 δ18O + 2.141 (R2 = 0.98) with a slope of less than 8, indicating that some non-equilibrium evaporation processes occurred when the drops fell below the cloud base. The isotopic regression line for the surface water was δ2H = 3.543 δ18O –19.227 (R2 = 0.95). The slope of surface water (∼ 3.543) was less than the LMWL (∼ 7.346) which indicated the enrichment effect of evaporation. It revealed that the isotope composition of surface water had a linear relationship with precipitation (R2 = 0.26) and enable to determine the evaporation loss of surface water. The stable isotopes of precipitation and surface water were combined with meteorological data to calculate the evaporation to inflow ratio (E/I) of Yom River in the study site during dry season (November-April) was 22.54% and during wet season (May-October) was 6.42 %.
A system displaying equipotential lines from electrodes in real time
Authors: Fongsuwan C , Teangsriwan P , Traiwan C , Buaprathoom S
Published: December 2019

Electric field is a fundamental quantity that is studied in the secondary and university levels. For the study, an experiment of finding equipotential lines from the charged electrodes is conducted. For the general experiment, the electric potentials are measured at various positions around the electrodes using a voltmeter. The measured data are then manually plotted to a graph to show the equipotential line. This experimental method is time-consuming (more than 1 hour in experiment). It is complicated to study of multiple electrodes using this experiment. Therefore, this research developed an experimental set that can display equipotential lines from various electrodes in real time. The developed experimental set uses a microcontroller (Arduino MEGA) to control a stepper motor to determine measuring positions of electric potential and measure electric potential at various positions around the electrodes (point of charge), automatically. The measured electric potentials and positions were plotted in contour graph to display patterns of the equipotential lines via a computer. The experimental set was tested using 2, 3 and 4 electrodes. The results showed that the developed system was able to display the equipotential lines of the electrodes within 2 minutes. The patterns of the equipotential lines were consistent with the equipotential lines generated from the theory. The correlations of the electric potential values from the experiments and the theoretical simulations for the systems of 2, 3 and 4 electrodes were 0.9452, 0.8691 and 0.9193, respectively. These results demonstrate that the presented experimental set can be used to display the equipotential lines from the electrodes effectively.
Cleaning contactor pins by laser
Authors: Topisit P , Ngamrungroj D , Duangchan S
Published: December 2019

In semiconductor final electrical testing manufacturing, the contactor pin is very important component as to make a contact between leads of devices to test hardware circuits. The contactor pins are made from metal alloy material which provide a good electrical conductive. In daily test manufacturing, the contactor pins may be up to several thousand contacting insertions, which will collect of many dust at their tips of contactor pins. The classic traditional cleaning of the contactor pins typically use abrasive cleaning, such as brush. In this research, we present the using of laser application to clean the contactor pins with Laser cleaning machine IMT model 600MV with Nd:YAG laser type. The optimized parameter setting up on the laser cleaning machine are studied with varies of number of pulse shot between 2-4 pulses, distance between the tip of contactor between 2-4 inches and energy of the Laser beam between 15-250 mJ/pulse. The cantilever contact pin type of majority used in one of IC Test manufacturing have been put into the evaluation. The testing of the cleaning effects is performed by optical power scope and scanning electron microscopy, including the analysis of metallic pin surface impacted was done by the EDX analyses. The parameters for cleaning effectiveness and safe cleaning of pins corrosion in metallic surface were determined.
Two conserved angular momenta in Schwarzschild spacetime geodesics
Authors: Musiri S
Published: December 2019

The present study investigated the geodesic paths in the 3+1 dimensional Schwarzschild spacetime. Four conserved parameters were found: the first is the conserved total energy: the second is the coordinate-invariant metrics: and the final two are the angular momenta (Pθ
and Pφ
) in the spherical coordinate. For θ = π/2 and when excluding a 1/c
2 term in the equation of motion, we recover the orbit equation of the two-body problem. But when not excluding that term, we recover the orbit precession, e.g. the perihelion precession of Mercury. When the value θ is not fixed, we found the equation of motion to be the radius r(θ) as a function of θ, which is similar to the function r(φ) for a fixed value of θ.
Modular panel house design with prefabricated production technology
Authors: Soegoto E S , Subarjat R , Valentina T
Published: December 2019

The purpose of this study is to get efficient home needs from modular panel houses at low cost and have a comfort factor and describe the design of the modular panel type house. This research method used the descriptive quantitative method, with research subjects describing the modular panel house design with its criteria. With the modular panel house building method would be easier with low costs compared to conventional because the industrial process was carried out with prefabrication, and pay attention to ecological factors in the building. Designed houses of modular panel house are built at low cost, taking into account thermal comfort factors and have eco-architectural values so that they can influence people’s interest in this type of house.
Safety factor analysis of landslides hazard as a result of rain condition infiltration on Buyan-Beratan Ancient Mountain
Authors: Sinarta I N , Basoka I W A
Published: December 2019

Disaster of soil movement from NDMA (National Disaster Management Authority) of Indonesia mention from 2003-2017 shows the increasing. Investigation of potential ground motion based on sampling data of boring test on slopes along the Denpasar-Singaraja road around Gitgit Village which provides the greatest threat to settlements and public facilities. This research is expected to show the influence of rainfall on slope stability. This research is expected to show the influence of rainfall on slope stability. Furthermore, safety factor analysis based on daily rainfall data and numerical analysis was assisted by SLOPE/W and SEEP/W software tools. The analysis was carried out using a normal, heavy, and very heavy rain model. Safety factor declined after the 3rd day of rain after that the safety factor dropped to the 6th day with a safety factor 1.141 indicating the condition to be critical. The result shows the effect of rainfall decreasing safety factor after the second day of rain and the fourth day of safety factor shows a value of 1.003 where the slope is in a critical condition leading to failure, these results can be used to make early warning system of landslide hazard.
The usage of a value engineering method for implementing green construction on the post graduate’s building at Warmadewa University
Authors: Suranata P G , Wahyuni P I , Triswandana I W G E
Published: December 2019

Green construction is a planning and implementation construction project with adjustment of construction methods and materials in order to minimize the negative effects from implementation of a construction project to the environment so that it can provide a balance between the environment ability and the needs of human beings. Each project construction certainly produce waste due to the construction method or material selection, therefore needed adjustment for construction method and material selection to reduce trash produced at the construction project. Replacement of construction methods and materials we’re not immediately be done to achieving green construction but first thorough analysis of value engineering. On this research, value engineering methods were used because it will conduct a systematic and creative approach and aims to obtain the best value a project with green construction used as a parameter to reach the required target values. This research takes places at Post Graduate’s Building on Warmadewa University where review focused on item or work that potentially produce waste construction waste. Obtained from this research that reducing the usage of wood like materials such as conventional formwork and lambersering solid wood were able to provide solid savings at least 11.50 % and also reducing construction waste.
Effect of changes in climatological parameters on water flow
Authors: Permana S , Susetyaningsih A , Zhafirah A , Mulyana S
Published: December 2019

The existence of rivers in an area is essential because it is often used by the community for daily needs. In addition to the availability of raw water, it is also used for agricultural purposes. Cipalebuh River with 42 km2 of river flow area is a river in the southern part of Garut Regency; this river is used for drinking water supply and for irrigating 1016 ha of the rice field area. The purpose of this study was to determine the magnitude of changes in the Cipalebuh river flow due to changes in climatological parameters such as average air temperature, average relative humidity, average wind speed, duration of solar radiation, air pressure, and solar radiation. The rainfall stations in the Cipalebuh river basin are the Pameungpeuk and Cisompet rainfall stations. Calculation of discharge using simulation method from F.J. Mock, while calculating evapotranspiration with the Penman-Monteith method. The apparent need for water in the rice fields is 1.4 lt/sec/ha. Based on the results of the calculation of the effect of changes in climatology parameters significantly influence the flow of water in the Cipalebuh river, so that the availability of raw water and irrigation is not much disturbed.
Model of ecological approaches to build community response to flood disasters
Authors: Susetyaningsih A , Permana S , Johari G J , Chandrahadinata D
Published: December 2019

In seeing the threat of a disaster, the community must have the capability to respond. Disaster risk increases for those who do not prepare themselves for the possibility of a disaster. The purpose of this study is to model the harmony of human interaction with the environment in which they live. Behavioural awareness of people living in disaster-prone areas can increase community resilience to disasters. The ecological approach is used to see the interaction of the community with its physical environment. The data of this study were obtained through in-depth observation and interviews of residents living on the banks of the Cimanuk river in Garut City District. Respondents were randomly selected from the community on the banks of the Cimanuk river affected by the Banjir Bandang in 2016. The results of the interviews were analyzed qualitatively. Physical environmental factors that form the adaptation of community behaviour are land characteristics, rainfall, river border conditions. Community behaviour in dealing with disaster risk is determined by the perception of self-determination that shapes attitudes and awareness of the safety of life and property. There are also social norms that strengthen people’s attitudes in disaster response efforts. River embankments, water monitoring posts, evacuation routes, funding sources, and institutions are supporting infrastructure for community interaction in responding to potential flood disasters and being a necessity in building disaster response communities.
Proportion limits the effect of mixture of red brick stone on concrete strength
Authors: Farida I , Krisdian A , Walujodjati E , Roestaman R
Published: December 2019

The proportion of concrete material affects the strength of concrete. The innovation of a mixture of waste red bricks can be used in concrete. The research method used experiments in the laboratory with normal concrete compressive strength compared to the composition of the mixture of red brick waste in the proportion of 25% and 50% based on SNI. The research objective was to find out the limits of the proportion of the design strength of normal K-200 concrete and by adding red brick waste as a fine aggregate substitute. The results of the use test with 25% and 50% of red brick waste are able to achieve the strength of the plan with reference to a normal concrete comparison so that the material is feasible as a substitute material. The addition of 50% waste is able to reach K-200 but compared to an additional 25%, there is a decrease in strength at 7 days at 16.7%, age 14 days by 20%, and age 24 days at 36.8%. Recommendation for the limit of the proportion of adding red brick waste to 25%.
Predicting the influence area of access and egress of commuter train based on survey data of travel behavior characteristics
Authors: Susanti A , Soemitro R A A , Suprayitno H
Published: December 2019

The main objective of this research is to predict the influence area of the SULAM Commuter Train when heading (Access) and leaving (Egress) the train station. The research method was carried out using an interview survey of SULAM commuter train passengers on weekdays in the morning departure hours (06.00-07.20) from Lamongan - Surabaya. Data on distance travel and connecting modes obtained from interview surveys are important data for calculating the influence area of the SULAM Commuter Train. The two data above are analysis gaps from the research. The influence area obtained from the Access-Egress interval, which is mostly chosen by SULAM Commuter train passengers, while data that is not widely selected can be ignored and considered as underserved territory. The value of the influence area can be viewed from each type of connection and is the renewal of this study. Planning new routes in underserved areas is a benefit of this research. Predictions about the influence area are important, given that the stretch of the commuter train service line in the city of Surabaya and its surrounding areas is still very limited.
Effect of the leakage location pattern on the speed of recovery in water supply networks
Authors: Nugroho W , Iriawan N
Published: December 2019

The International Water Association states that Non-Revenue Water is an efficient indicator of the performance of a water company that has been implemented internationally. The volume of water loss expressed as Non-Revenue Water at the global level shows a high number. Every year more than 32 billion m3 of treated water is lost due to leakage from the distribution network. There are four pillars in the network leakage management strategy include management of pressure, speed of recovery, active leakage control, and asset management. These components influence how leakage is managed and affect the volume and value of economic leakage - in a distribution network of water companies. The current annual volume of physical losses tends to increase along with the expansion service area of the distribution network. The rate of increase can be inhibited by the right strategy combining the four components into an effective leakage management strategy. This study analyzes the distribution pattern of leakage points in water distribution pipelines in Malang City, and how much they affect the speed of recovery. The data in this study consist of 5449 pipeline leakage points which include spatial and attributes data. The method used in this study is the Spatial Point Process. The results of the analysis show that the distribution pattern of leakage is an inhomogeneous pattern. It is found that the parameters of the model -with Euclidean distance- the leakage pattern affects the occurrence of leakage and the Geographical Weighted Regression model -with fixed Gaussian Kernel Weight Function with Manhattan distance- the leakage pattern affects the speed of recovery.
Identification of the inhibiting factors for skilled labour in the construction sector to obtain competency certification
Authors: Widiasanti I , Rochadi D , Fridestu A , Lenggogeni L
Published: December 2019

The purpose of competency certification can be seen from two complementary aspects, namely to assess a person’s ability and expertise in his profession and convincing the user about the competency of the labour which fulfills the requirements in carrying out the task. However, the number of construction labour certified is only about 3% of all construction labour in Indonesia. This study aims to identify inhibiting factors of competency certification in the perspective of construction labour, especially skilled labour. This study uses a quantitative model with descriptive analysis. This research was conducted on skilled labour in three high-level building projects. The method of collecting data by survey through questionnaires, observation, and literature study. The results of this study indicate several factors which interfering skilled labour to obtain competency certification: 1) the complexity of competency certification implementation, 2) The expensive cost to get the competency certification, 3) There is no difference in wages between certified labours and uncertified labours, 4) The certificate does not guarantee the work quality of labours.
Risk management maturity of the supervising consultant on quality and time performances in construction building
Authors: Suryani F , Widiasanti I , Nurjaman H N , Ramdani I J
Published: December 2019

Construction of buildings has a complex type of work. Detailed work does not only refer to the technical specifications and drawing plans that have been set, but there are also construction norms and work steps that need to be understood by the Supervising Consultant in achieving project objectives. There are often problems with quality and time control, so the ability to manage risk from the Supervising Consultant needs to be known and analyzed. Based on this analysis, it can be determined the level of risk maturity of the Supervising Consultant in overseeing the implementation of building construction. The purpose of this study is to obtain the maturity level of the Supervising Consultant in managing risks related to quality and time performances. This study uses descriptive analysis and Analytic Hierarchy Process (AHP) to get category in risk control. The results of the study indicate that the Enterprise Risk Maturity criteria assessor obtained maturity level 4. This means that the Supervising Consultant has a supervisory system on the implementation of risk management, the principles have been implemented and accompanied by periodic improvements in terms of control.
Soil characteristics analysis based on the unified soil classification system
Authors: Daryati D , Widiasanti I , Septiandini E , Ramadhan M A , Sambowo K A , Purnomo A
Published: December 2019

The purpose of this research is to determine soil classification and identify the swelling potential of soil clay in the Jababeka I (sample 1) and the Lippo Cikarang (sample 2), Indonesia. The research was carried out by the experimental method. Soil classification based on the Unified Soil Classification Systems (USCS) determined by No.200 sieve analysis and A-chart (LL vs PI chart), while based on the American Association of State Highway and Transportation Officials Soil Classification System (AASTHO), classification determined by No.200 sieve analysis, liquid limit (LL) and plasticity index (PI). The results show the soils are clay of high plasticity (CH) in determining of the USCS, whereas in AASTHO, the soils are A7-6, which means clay of high plasticity. Furthermore, the swelling potential or expansion potential of clay is determined by indirect methods namely by the results of LL, PI, SL, and percentage of the passing of sieve No.200. Moreover, consolidation test is also carried out to obtain compression coefficient (Cv) and coefficient of consolidation (Cc) to determine the mineral content. The results of this experimental research that soils contain kaolinite minerals, a very high swelling potential with the possible change in volume of 10-30 %.
Physical condition-based practice models of traditional games for children disabled elementary school age
Authors: Repiyasa I W , Tangkudung J A P , Hernawan  , Paramitha S T
Published: December 2019

This research has the goal of producing products such as exercise books and models in the physical condition of child disability. in this study using Borg and Gall method consists of ten steps and Research subjects are elementary students in SLB B PTN Bali. The model consists of 4 models with 40 items which have several times through the expert evaluation, testing and revision. This research uses pretest and posttest with significance level 0,05. The result of physical game exercise based on traditional game for children with disability between pretest and posttest obtained result tO = 9.595 bigger than price tt = 0.000 (at significance level 0,05), hence null hypothesis rejected. So, it can be concluded that there are significant differences between pretest and posttest results-based endurance exercise traditional games for children disabilities. Judging from the results of the physical condition of the model-based practice of traditional games for children of primary school age disabilities are effectively used to improve the results of the child’s physical condition.
Identification of supporting factors of local food products towards the global market competition
Authors: Ikhwana A , Kurniawati R , Kurniawan W A , Alinda F P
Published: December 2019

Local food products that have been known as icons of a region are faced with global market competition so that they are required to have competitiveness in fighting for the global market with the hope that business activities that rely on local identity are not lost and displaced by the arrival of various products that can replace product functions and roles on global competition. This study aims to identify the factors that support the sustainability of the local food product business so that it can compete in the global market and determine the strategies that must be done. To support this research activity, the method used is the analysis of factors supported by 100 respondents conducted using the accidental sampling method involving various groups of respondents. Based on the results of the study, it was found multiple factors that support the sustainability of local food product businesses, namely: lifestyle factors, individual factors, promotion factors and places, and product identity factors. Furthermore, so that the business activities of local food products can survive and be sustainable, the strategies that must be carried out are product innovation, intensive promotion, and determining a strategic sales location.
Determination of the optimal distribution centre location with gravity location model
Authors: Sanjaya A , Sembiring A C , Willyanto W
Published: December 2019

Distribution cost for an animal feed company in Deli Serdang is relatively difficult to reduce because the location of the distribution centre is not strategic and far from several distribution locations. The purpose of this research is to determine the optimal distribution centre location to reduce distribution costs. In determining the proposed distribution centre location, Gravity Location Model is used. The research results are the new coordinates as the proposed distribution centre location, namely (98.888504; 3.419406) and the total distribution costs of initial distribution centre location are Rp 7.135.828, while the total distribution cost of proposed distribution centre location is Rp 6.965.143. The results obtained show that the total distribution costs can be reduced by 2.39% per day.
Problem solving improvement through the teaching factory model
Authors: Subekti S , Ana A , Barliana M S , Khoerunnisa I
Published: December 2019

The dominance of Indonesia’s youth unemployment rate is currently occupied by vocational school graduates. The incompatibility of competencies prepared in vocational schools with the competencies needed by the labour market triggers this unemployment rate. Discussion of employability skills as a basic skill is high among human resource developers. The learning process must pay attention to the profile of labour needed so that the gap can be overcome. This study aims to measure the increase in employability skills in problem solving skills of students through teaching factory model. The study sample was 60 students from vocational schools who conducted teaching factory on bread production in West Java. Improved problem solving skills are measured based on 5 indicators, are work safety, managing facilities, making decisions, knowing how to learn, and solving problems. 37 competency units are prepared based on national work standards as a guideline for measuring students’ problem solving skills. Achievement of employability skills in problem solving skills of students in SMKN 1 Pacet is higher than SMKN 1 Cibadak, and SMKN 2 Subang. The causes of differences in the achievement of employability skills are discussed.
The bread production process using application of the Hotelling T2 control chart
Authors: Asri G S , Citra F P , Nisa S K , Lestari T E
Published: December 2019

Quality Control is an activity to maintain and direct to quality company product and services which can maintain the existence of the product in the long term period. Statistical Quality Control is a method of using the control charts of the cause-effect techniques and diagrams in quality control to minimize the rejected products. In this study, we used one of Statistical Quality Control methods, which is Hotelling T2 Control Chart to control the quality of bread production. Hotelling T2 Control chart is the type of multivariate control chart that is used to monitor the process of identifying the causes of variance and improve the process. In the application of the Hotelling T2 Control Chart, we used two major characteristics of quality, those are size and net. Based on the identification the number of products that fail is still within reasonable limits located between UCL and LCL. The main cause of the signal out of control is the packaging of the product. As the endeavour improvement from the company, the production process is increasing in the second phase.
The effect of addition of polymer on viscosity as fluid of industrial oil and gas injection in EOR method
Authors: Pramadika H , Samsol S , Satiyawira B
Published: December 2019

One EOR injection is polymer injection. In this study we will use FP3300S polymer with a concentration of 500ppm, 750ppm, 1,000ppm, 1,250ppm, 1,500ppm, 1,750ppm, 2,000ppm, 2,250ppm and 2,500ppm. The purpose and objective of this study was to determine the effect of polymer concentration on increasing viscosity, determine the effect of polymer concentration on polymer filtration (compatibility, filtration, screen factor, thermal stability), and to find out how the polymer injection results, the higher the research found. the polymer concentration the higher the viscosity where the highest at the polymer concentration 2,500ppm with 19,38cp, the viscosity required by the polymer as injection liquid is the viscosity of the polymer greater than 2X the viscosity of the oil to be injected, where the oil viscosity is 5,2pp. then while in polymer screening it was found that higher polymer concentrations were not always good for polymer filtration, and polymer injection has been shown to increase recovery factor, recovery factor was obtained at 51.5% water injection and polymer injection was 23.1%, before injection was correct really need to be screened first, to get the most optimal concentration to be injected.
Application of artificial neural network to predict permeability value of the reservoir rock
Authors: Yasmaniar G , Prakoso S , Sitaresmi R
Published: December 2019

Permeability is an important reservoir property but it is difficult to predict. An accurate measurement of permeability values can be obtained from core data analysis. However, this analysis is not possible to do at all interval wells in the field, so that permeability information becomes incomplete. Then, the use of artificial neural network method can be an alternative to predict the incomplete permeability values. This study used 191 of sandstone core samples from Upper Cibulakan Formation in the North West Java Basin. These core data were used to determine hydraulic flow unit (HFU) from the reservoir, and to obtain a relationship between porosity and permeability for each HFU. The application of artificial neural network method is done by building a database of flow zone indicator (FZI) based on its relationship with log data. From this FZI value, the HFU class can be known. Afterward, the permeability value can be obtained according to the equation of the relationship between porosity and permeability at each HFU that had been generated. Artificial neural network was applied on G-19 and G-11 Well that had 51 of core data. Based on this study, the result of permeability value is not much different from core data at the same depth, so that this method can be applied to obtain the permeability in uncored intervals.
Comparison of methods for calculating gas reserves in providing certainty of reserves in the oil and gas industry
Authors: Rahmawan S , Ridaliyani O , Samsol S
Published: December 2019

The volumetric method is the initial method used in calculating hydrocarbon reserves obtained from the exploration stage obtained geological data from a field in the oil and gas industry. The hydrocarbon reserve calculation obtained from a volumetric method is the result of interpretation data, such as seismic and logging data that have a small range of trust. In this study estimated hydrocarbon reserves in the XY formation gas reservoir using a material balance method or P/Z method in assessing optimism or pessimism of the reserve value generated from a volumetric method. The material balance method or P/Z method was chosen as a reliable method. Because it has better accuracy data such as pressure measurement data, reservoir rock, and fluid analysis data. Cumulative production measurement data compared to interpretation data on a volumetric method. From this research can be concluded that the reserve value produced by the volumetric method is more pessimistic than the reserve value using the material balance method and P/Z method. By knowing pessimism results from the volumetric backup method for the other two methods. it will affect the amount of oil and gas industry reserves so that geological model needs to be done again after more accurate data is obtained.
Construction design system of constant pressure control in water distribution system with PID method using PLC based on IoT
Authors: Syufrijal S , Rif’an M , Media’s E
Published: December 2019

The objective of this research is to make a constant pressure control in water supply with the method of PID using PLC Siemens S7-1200 as a controller and also to monitor the process of its work system from a distance through the internet of things (IoT). The water distribution system is created utilizing 3 phase pump which will supply water from the tank. The pressure sensor will be used as an analog input signal of PLC to detect the pressure of water in the pipe. Using inverter, water pressure will be kept constantly matched with the desired set point through the setting of pump speed using the digital PID method that is available on PLC. The score of the set point is done through HMI of touch panel KTP700basic. By using Wi-Fi communication that has been connected to the internet, PLC data can be sent to a cloud server through raspberry pi3 using the MQTT protocol. Raspberry pi3 program is designed using the java script coding language. Research result showing that this system can keep the water pressure at a constant level of 1.2 bar in the water supply. It is also able to monitor the water pressure through HMI and handphone via IoT Technology in the GoIoT server.