bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk in Implementing Building Information Modelling (BIM) in Malaysia Construction Industry: A Review
Authors: Mat Ya’acob Ibtisam Azwani , Mohd Rahim Faizul Azli , Zainon Nurshuhada
Published: November 2018

Building Information Modelling (BIM) terminology in the construction industry has been widespread used as industry standard buzzword term. BIM could open up a broad range of benefits in the construction industry. However, rate of implementation does not match its benefits. Why BIM has not been fully adopted in construction industry? The underlying problem to the above-mentioned issue were arisen due to the barriers, challenges and risks. These can be a potential factor to jeopardise the successfulness of the construction project by affecting the cost, time and quality. The said factors can be an actual risk which later on bringing construction project to failure. Thus, it crucial to identify the potential risk as a basis for risk assessment and risk response process. Moreover, risk identification relatively important since the risk assessment and risk response process are applied only to the regornised risk factors. Therefore, the aim for this paper is to review the possible risks in implementing BIM in construction industry.
Teaching Strategies Employed by Academics in STEM Education: A Qualitative Inquiry
Authors: Kunalan Amutha , Cheah Phaik Kin , Moses Priscilla , Er Pek Hoon , Ng Choon Aun
Published: November 2018

Science, Technology, Engineering and Mathematics (STEM) education needs a teaching workforce that is knowledgeable and skillful. Previous studies have reported the effectiveness of the delivery of the STEM education using the outcome-based education approach. Yet, the implementation of STEM education has been equally criticized. This study is a qualitative inquiry using the grounded theory approach to identify the teaching strategies employed by academics involved in STEM education in a leading private university in Malaysia. In particular, the inquiry focusses on the outcome-based education and its implementation in STEM education. Eight academics involved in STEM education from a private university in Malaysia were recruited using a purposive sampling procedure. In-depth interviews were conducted using semi-structured questions. The findings suggest that the participants are apprehensive of using outcome-based education in implementing STEM education and would require more training on this approach. The data yielded teaching strategies and challenges faced by STEM academics in the implementation of outcome-based education.
Beauty in Eco-Technology – A Sewage Treatment Plant as a Spatially Attractive Structure
Authors: Wójtowicz-Wróbel Agnieszka
Published: November 2018

The increasing awareness of the protection of depleting natural resources results in new challenges for us to face. The necessity to treat domestic water is one of such basic challenges. The intensive development of modern technological solutions in this field creates new possibilities - including those related to the architectural shaping of structures. Simultaneously - following the example of other municipal infrastructure buildings - thanks to the development of technology - sewage treatment plants become structures that are more accessible and spatially attractive. The goal of this article is to answer the question whether these types of urban engineering elements can constitute a structure that is spatially attractive in terms of the tissue of urban and suburban areas, and if so, then under what conditions? The study was performed using a method of analysing a selection of structures in Poland (the first part of the article), in addition to an analysis of examples of good practice regarding such projects in other countries, which constitute state of the art aesthetic solutions in this regard (the second part of the article). The result of the study will allow finding the answer to the question: what is it that causes some sewage treatment plants to have the opportunity to become a significant spatial element, while others only fulfil their technological functions? The results of the analyses performed by the author could form the basis for performing comparative studies of this scope on other examples, including both sewage treatment plants, as well as other municipal infrastructure buildings of a city.
Facile Synthesis of ZnO Flower-Like Micro/nanostructures with Enhanced Antibacterial Activity
Authors: Wong Kok Ann , Lam Sze Mun , Sin Jin Chung
Published: November 2018

Flower-like ZnO micro/nanostructures were synthesized via a simple reflux route without addition of surfactant. The characterization of as-synthesized ZnO sample was performed using X-ray diffraction, field-emission scanning electron microscopy and photoluminescence spectroscopy. The activity of the as-synthesized photocatalyst was evaluated using colony counting method under UV irradiation. The results showed that the as-synthesized ZnO sample exhibited excellent photocatalytic disinfection towards Escherichia coli. A possible disinfection mechanism was also postulated based on the findings from microscopic images and radical scavenging experiments.
Solar Light Harvesting N-Graphene Quantum Dots Decorated TiO2 for Enhanced Photocatalytic Activity
Authors: Lim Ping Feng , Hak Chen Hong , Leong Kah Hon , Sim Lan Ching , Saravanan Pichiah
Published: November 2018

N co-doped graphene quantum dots (N-GQDs) incorporated with nanocubic likes titanium dioxide (TiO2) are synthesized via facile hydrothermal method. The morphology features of the synthesized N-GQDs/TiO2 nanocomposites are seen to exhibited in cubic shape. The average lateral size of the synthesized nanocomposites is found to be ~5.1 nm. UV-Vis absorption spectra show vastly improvement in the visible light range when N-GQDs is introduced to TiO2. The photocatalytic activity clearly demonstrated its solar light harvesting capability of prepared nanocomposites by photodegrading 4-chlorophenol (4-CP) under sunlight irradiation.
Numerical Study on Improving the Efficiency of the Earth Pipe Cooling System
Authors: Saha Parnab , Galib Musanna , Mahdi-Ul-Ishtiaque Md. , Akanda Shamimur Rahman , Hannan Mohammed Abdul
Published: November 2018

Earth pipe cooling (EPC) is one of the passive cooling systems which has proven to be a very energy efficient sustainable cooling technique for the sub-tropical areas. This cooling system uses the soil as a medium of heat transfer. Efficiency of this system largely depends on the velocity of the cooling air, shape of the cooling space, pattern of the walls in cooling space, inlet size and position of the incoming air. It is well-known that increasing the velocity of the cooling air will improve the efficiency of the cooling system. Therefore, this study focused on the optimization of the shape and pattern of the inlet which might improve the efficiency of the cooling system. ANSYS Fluent is used to perform this simulation-based study. It is found that inclusion of aerofoil shaped turbulator in the inlet cross sectional area provide better circulation of the air inside the cooling space, thus, enhance the effectiveness of the system.
Performance Evaluation of Reverse Osmosis Desalination Pilot Plants using ROSA Simulation Software
Authors: Chee Kok Pol , Wai Kok Poh , Koo Chai Hoon , Chong Woon Chan
Published: November 2018

Desalination allows the use of non-conventional water sources such as seawater for the production of potable water. The performance of three pilot plants in Mallard Slough, namely RO1, RO2 and NF3 were investigated. Reverse Osmosis System Analysis (ROSA), a simulation software was adopted for verifying the performance of the existing pilot plants in treating seawater. By inserting the specific system configuration and selecting the membrane specification of the pilot plants, ROSA would help to generate the operating parameters such as feed pressure, flux, recovery ratio, permeate quality of the plants. These results were subsequently being used to compare with the experimental data of the pilot plants to determine their absolute deviations. It was found that all ROSA simulated feed pressures for RO1, RO2 and NF3 fell in the range of operational feed pressures of the existing pilot plants. Besides, the deviation of total dissolved solutes removal between the results simulated by the ROSA software and the results obtained from the experiments were noticeably insignificant. In terms of flux and recovery ratio, the simulated results and the experimental data showed a marginal discrepancy with deviations < 2% and < 8% for RO1 and NF3, respectively. In conclusion, the findings of this study confirmed the feasibility of adopting this ROSA software to verify the performance of a pilot plant with all operational parameters being ideally optimized.
Effect of Recycled Plastic in Mortar and Concrete and the Application of Gamma Irradiation - A Review
Authors: Usman Aliyu , Sutanto Muslich Hartadi , Napiah Madzlan
Published: November 2018

The utilization of a large amount of waste in concrete production is considered the best alternative for solving the issues associated with improper disposal. Plastic waste is considered as one of such waste and could be utilized in several applications. The drawback associated with the utilization of a large amount of plastic waste is the decrease in the mechanical properties of the mortar or concrete as the case may be. This paper presents a detailed review about waste recycled plastics and research published on the effect of non-irradiated recycled plastic on the mechanical properties of cement mortar and cement concretes as either fillers or aggregates and the application of gamma radiation on the recycled plastic waste. The effect of recycled waste plastic on compressive strength, flexural strength and splitting tensile strength is discussed in this paper.
Misuse of Lambda (λ) in NRCS-CN Model
Authors: Tan Wen Jia , Khor Jen Feng , Ling Lloyd , Huang Yuk Feng
Published: November 2018

Since 1954, the Soil Conservation Curve Number (SCS-CN) method is widely applied in hydrological field to predict the direct runoff resulting from event rainfall. Originally, the lambda value was fixed at 0.2. However, based on recent studies, the simplied SCS-CN method was unable to predict a consistent and accurate runoff amount. Most of the research studies in various countries claimed that lambda value was a variable and most likely should be less than 0.2. Most of the researchers applied either mean or median λ value directly without checking the statistics. Misuse of lambda value in SCS-CN model will lead to inconsistent runoff estimation. Moreover, although λ value can be determined, the equivalent CN0.2 cannot be found. Some of research studies or even Hydrology Textbook substitute Sλ directly into CN equation and lead to wrong CN calculation. In this study, the statistical significant λ value and regional specific S correlation are developed under the guide of non-parametric inferential statistics. by using bootstrapping, Bias corrected and accelerated (BCa) technique with 2000 samples.
Stress Evaluation for Segmental Concrete Box Girder Diaphragm
Authors: Lim Pei San Alice , Choo Wen Yi , Ong Chuan Fang , Lau See Hung
Published: November 2018

The box girder component is a major breakthrough in the construction field for its effective geometry behavior and high torsional rigidity. However, the analysis and design of the box girder are complex due to its three dimensional behavior i.e. torsion, distortion and bending in longitudinal and transverse direction. In this paper, the use of finite element model in evaluating the stresses behavior for segmental box girder diaphragm under static loading is demonstrated. The analysis is carried out for both permanent and variable actions based on Eurocode. Parametric study is carried out to evaluate the effects of different parameters on the stress behavior for box girder. This study contributes to a better insight of the stress behavior for box girder such that, under service, the stresses developed will not contribute to significance structural cracks that will affect the serviceability of the structure.
Modification of the Beam as Solution of Irregular Building due to Seismic Load
Authors: Sumarsono Ririt Aprilin , Fajari Muhammad Aji
Published: November 2018

In recent years, deterioration due to seismic activity has been widely emerged in earthquake prone areas all over the world. Most structures without seismic consideration fail massively due to many reasons, for instance: irregularity problem, low quality of material, reinforcement insufficiency, and so forth. This paper will highlight the analysis of the irregular building simulation using dilatation by modifying the beam in some re-entrant corners and create it as separation inside the building. Variation of placement for the modified beam is examined to the applied high rise building; specifically console beam and Gerber beam. Convincingly, console beam is identified to provide better result for overcoming irregularity problem for both horizontal and vertical irregularity whereas period of structure can be shortened by attempting it as well as other behaviour parameters. Shear wall appearance will certainly increase the performance of the structure, but it will be necessarily needed for Gerber beam rather than console beam. Eminency of Gerber beam is greater probability for reducing the mass of structure since the dimension can be adjusted to be smaller than the main beam; otherwise further consideration of cantilever and intermediate span of the Gerber beam needs extra efforts.
Shipping Container as Shelter Provision Solution for Post-Disaster Reconstruction
Authors: Tan Cher Siang , Ling Philip C.H.
Published: November 2018

The emerging of shipping container house can help to relief the challenging issue in provision of dwelling in certain countries with overpopulation or surge of refugee. However, the suitability of shipping container, which is initially designed for transportation purpose, for shelter usage is not well understand. This paper aims to understand the current research on the technical aspect of container for shelter provision and the gaps of knowledges. Literature review is done on the up-to-date research about the container shelter and the potential of container shelter is summarized. From the study, shipping container can be suitable for shelter provision with some improvement to be done.
The Empirical Study on the Impact of Road Gradient and Truck Composition on the Toll Road Traffic Performance
Authors: Nahry  , Fadillah Noor Syiffa
Published: November 2018

The Jakarta Outer Ring Road (JORR) is a toll road system that circles the outskirts of Jakarta, where the purpose of this road is to reduce congestion on the street network of the city centre of Jakarta. However, the high composition of trucks in JORR resulted in congestion, and moreover it is suspected that the steep gradient of this road has contributed to this situation. This study aims to investigate the impact of road gradient on the trucks and the overall traffic performance from macroscopic view point. This study is the complement to a similar study that has been done in JORR previously, to confirm the result. The previous study was based on the Vissim simulation, while this paper will be entirely focused on an empirical study. Using the data obtained from 24-hour traffic recording on selected JORR sections that represent various gradients, traffic flow models are generated, and the effect of gradient could be assessed. The speed difference between trucks and non-trucks shows 56.2%~127% gap as the result of different gradient occurred. The overall free flow speed (uf) difference of different gradient is up to 27.3%. This result will benefit to the transport authority to justify the policy concerning the existence of trucks in the traffic flow, particularly in the condition at which trucks are regarded as a culprit of traffic congestion.
Road Sign Detection Distance and Reading Distance at an Uncontrolled Intersection
Authors: Priambodo Mohamad Ihsan , Siregar Martha Leni
Published: November 2018

A traffic sign needs to be located at a distance that allows drivers to read and understand the message prior to their decision in manoeuvring. The study is aimed at evaluating signs visibility at intersections without traffic lights using the drivers reading distance and detection distance. A total of 35 participants with valid driver’s licences were asked to detect and read 6 advance guide signs at an intersection without traffic lights on an urban road. Factors that potentially determine signs readability and visibility such as vehicle’s speed, vehicle’s travelling time, signs vertical offset and signs letter height which affect signs detection distance and reading distance are analyzed using multivariate regression. The experiment was conducted during night time to present heavier driving and sign reading environment. The positions of the signs were evaluated based on the actual sign positions and the detection and reading distances. Some of the findings include that vehicle travel time, vehicle speed, sign letter height, and sign vertical offset all significantly have a relationship with the sign reading distance whilst sign letter height does not have a significant relationship with the detection distance. The study also evaluated the signs compliance with the applied standards.
3D model of Sin Quyen iron oxide copper deposit in Lao Cai, North Vietnam
Authors: Duong Van Hao , Nguyen Dinh Chau , Zygo Władysław
Published: November 2018

The paper presents a 3D model of ore bodies of the Sin Quyen iron oxide copper-gold deposit in Lao Cai province, North Vietnam. To build 3D model we used the computer software MineScape and archival geological, geophysical data recorded from 146 boreholes, 21 tunnels and 216 trenches, including the data obtained from chemical and neutron instrumental activation analysis of 50 ore samples collected in 2015 year. The modelling process was composed of three stages: first was checking and validating of the input data, second was data processing and the last building 3D model. The model shows that the ore bodies extend below level of -300 m, such information will be used for future exploration. Based on the obtained model, the reserves of selected metals were calculated and equal to 570 000 tonnes for copper and 190 tonnes for uranium. The obtained Cu reserve is comparable with that estimated and published in the archival report of the Vietnam Geological Department.
Nonlinear anisotropic diffusion techniques for seismic signal enhancing - Carpathian Foredeep study
Authors: Zaręba Mateusz , Danek Tomasz
Published: November 2018

The use of nonlinear anisotropic diffusion algorithm for advanced seismic signal processing in the complicated geological region of Carpathian Foredeep was examined. This technique allows for an improvement of seismic data quality and for more accurate interpretation by the recovery of a significant amount of structural information in the form of a correlating seismic reflections and by preserving true DHI indicators. It also allows searching for more subtle geological structures. Anisotropic diffusion is an iterative image processing algorithm that removes noise by modifying the data by solving partial differential equations. Moreover, it can reduce image noise without blurring the edges between regions of different chrominance or brightness. This filter preserves edges, lines, or other features relevant to the seismic structural and stratigraphic interpretation. The algorithm also enables noise reduction without removing significant information from a seismic section even for high dips values. For a better estimation of anisotropic diffusion structure tensor, the parameterization is done using the depth field and the calculations in the two-way travel time field. The presented research shows the results of using an anisotropic diffusion algorithm for post-stack and migration processing of seismic 3D data collected in Carpathian reservoir rocks of southern Poland.
Inversion of velocity parameters in multilayered elliptical anisotropy medium - synthetic data example
Authors: Gierlach Bartosz , Danek Tomasz
Published: November 2018

In the medium composed of parallel sedimentary layers, model of elliptic anisotropy is often better approximation of real conditions than simple layers with constant velocity. In such model a velocity is described with 3 parameters: a, b (responsible for vertical velocity and its gradient) and χ - elliptic anisotropy coefficient, describing changes of velocity with direction of wave propagation. In this case, seismic rays are no longer straight lines but elliptic-shaped curves. In this contribution we present a tool for inversion of velocity parameters in multilayered medium considering model of elliptic anisotropy. Input data contains measured traveltimes of direct wave between all sources and receivers. The depth of boundaries and existence of elliptic anisotropy in specific layers are not subject of inversion. In order to obtain each synthetic traveltime, necessary for the target function, ray tracing must be carried out using Fermat’s principle directly. The optimization in both parameters inversion and ray tracing is local and performed with Simplex algorithm from GSL library. The tests of the tool was conducted on the synthetic data with various types of start model containing one or more layers with or without elliptic anisotropy.
The comparative analysis of the seismic test results performed using the cross-hole and down-hole methods in terms of test reliability and efficiency
Authors: Tschuschke Wojciech , Gogolik Sławomir , Kroll Maciej , Janicki Krzysztof
Published: November 2018

Seismic tests are becoming more and more meaningful in modern geoengineering since they allow precise assessment of changes in the analyzed profile of soil deformation parameters at very small strain. The engineering practice generally uses two methods for such kinds of tests: reference cross-hole test and commercial down-hole method. The costs of implementation of this kind of research and the reliability of the results obtained along with any additional benefits from the type of the selected testing technique are not without significance. Seismic measurements for which comparative analysis was performed were carried out in a strongly anisotropic materials base of a tailings. The results of tests conducted with a standard cross-hole method were compared with those conducted using the down-hole method, in which the seismic piezocone (SCPTU) and seismic dilatometer (SDMT) were used. Test results have shown that in terms of assessment of their credibility, there were no fundamental differences in the quality of the recorded signals. It has been pointed out, however, that there are many advantages to penetration in situ tests, which complement identification of subsoil structure with many crucial elements that cannot be achieved using the cross-hole method.
Application of the mineral liberation analysis (MLA) for extraction of grain size and shape measurements in siliciclastic sedimentary rocks
Authors: Pszonka Joanna , Sala Dariusz
Published: November 2018

The mineral liberation analysis setup (MLA) consists of a scanning electron microscope (SEM) - based backscattered electron (BSE) image with an energy dispersive X-ray system (EDX) for elemental analysis and a computer software that integrates images and X-ray identification of minerals and maps their distribution. Thereby, various quantitative and qualitative data sets are collected including grain size distribution and shape parameters such as aspect ratio, shape factor and angularity. Other techniques, e.g. the Gazzi-Dickinson point counting method or frequently questionable image analysis software to extract data for textural analysis are time consuming, strenuous and with limitations that need to be addressed. Significant productivity of the mineral liberation analysis provides statistical representation and thereby stringent arguments to detect and suggest some potential solving in uncertainty and complexity of the submarine gravity flows phenomenon that is extremely difficult to monitor, however volumetrically the most significant processes moving sediments on Earth. The mineral liberation analysis seems to be one of the most suitable method to acquire such data set.
S-wave velocity in samples of calcareous waste
Authors: Pilecka Elżbieta , Zięba Jakub , Pilecki Rafał
Published: November 2018

The studies have been carried out in the calcareous waste area “White Seas” of the closed factory Solvay Sodium Plant in Krakow in southern Poland. The study was conducted to determine the S-wave velocity of samples of the anthropogenic subsoil. It was aimed at the possibility of using post-production waste for construction purposes. Due to the high humidity of the analysed samples, the tests were carried out on samples taken using Shelby type probes, from the 12m borehole. The saturation level of soil samples was estimated based on Skempton’s law (B>0.95). The Swave velocity was determined depending on the different degree of saturation as well as the different degree of consolidation of the soil sample. Only S-wave velocity was analysed because properties of samples caused difficulties in determining of the first arrivals of P-wave. The measurements were carried out in the triaxial apparatus equipped with Bender element (BE). Finally, the shear modulus G of the samples were calculated. Results showed the effect of S-wave velocity increase with increase of degree of saturation and with the increase of effective stress in tested samples. The Swave velocity significant increased up to about 100 kPa, and then this increase was smaller.
Assessment of parting rock weak zones under the joint and downward mining of coal seams
Authors: Bondarenko Volodymyr , Kovalevska Iryna , Symanovych Hennadii , Barabash Mykhailo , Snihur Vasyl
Published: November 2018

The aim of the forecasting effort is to identify troublesome zones of stability loss by a parting lengthwise of the extraction panel under the joint and downward mining of coal seams. Analyses have been carried out of active stress component curves for a 3-D model computational experiment compared with the strength characteristic of each lithotype of a parting. An algorithm has been developed for the stability assessment of a parting lengthwise along the extraction panel. The relationship patterns have been estimated between the sizes of the parting rocks discontinuity zones and the main geomechanical parameters. A scientifically grounded basis has been created for the detection of the parting rock weak zones lengthwise along the extraction panel for the calculation of the mounting and security systems of the development works. A complex of underground instrumental observations was made, which was used to set up a correspondence of patterns to indicate the variation in rock pressure manifestation intensity and the tendencies for changes in the parting structure. All of this confirms the adequacy of the techniques for parting state forecasting, which is recommended for use in the engineering documentation for the joint and downward mining of coal seams.
Identification of zones of increased permeability using numerical modelling of temperature distribution - an ISMOP case study
Authors: Dwornik Maciej , Franczyk Anna , Leśniak Andrzej
Published: November 2018

The physical condition of earthen levees changes over time. Levee weakening can be caused by the leaching of fine grains of soil or by animal activity. Weakened areas can potentially cause destabilization or even collapse. Assessment of the physical condition of levees using GPR and geodetic measurements does not always correctly detect areas of increased permeability.

Thermal anomalies, caused by existing zones of high permeability, are observed in levees during the transition of flood waves. They are generated by rapid infiltration of water with a different temperature than the temperature inside the levee. Therefore, inner thermal measurements may be used to detect places with higher permeability. This research was realized with 2D numerical modelling. Main aim was test possibility of using temperature sensors in weak zone detection. Test with different theoretical permeabilities proved that it is possible only in specific condition (i.e. thermal contrast). The geometry and geomechanical properties of the studied levee were taken from the ISMOP project (polish acronym: Computer system for monitoring river embankments).
Study on national activities and funding opportunities of furthering education programs for unemployed academics
Authors: Rahner Susanne , Winter Ilona , Hartmann Michael , Wittich Frank , Kasztelewicz Aleksandra , Tomaszewska Barbara , Pająk Leszek , Dendys Marta , Operacz Agnieszka , Mraz Marta , Nistor Stelian
Published: November 2018

The joint German - Hungarian - Polish - Romanian Project EUBILD-UNAKLIM 2016-1-DE02-KA204-003254 in the ERASMUS + Scheme KA2 (Strategic Partnerships) designs an international adult-learning furthering education course. It took place in the participating countries Germany, Hungary, Poland and Romania. Environmental and cross-sector topics were addressed. A “green” job search and a questionnaire among employers, financing and educational institutions and NGOs was performed across the partner countries in 2017. The objectives were to find differences in employers’ opinions on staff skills and the training topics provided by the furthering education organizations. In case differences were found, the course could close these gaps and will be adapted to the employers’ needs, bringing more course participants into employment. Statistical evaluation compared countries, institution types, employers and furthering educationand financing institutions. The results were visualized in pie charts, histograms, and - where applicable - trend lines. Preliminary results show clear ranking of the new “green” job categories with differences in countries and institutions. The questionnaire results show differences in topic selection between employers and furthering education bodies. The results form the base for the course curriculum design closing the gaps between employers’ expectations for “green” job topics and existing training curricula.
Tofu wastewater treatment using contact glow discharge electrolysis method and air injection
Authors: Permatasari Nadira Kamilia , Pangestika Widya , Saksono Nelson
Published: November 2018

Tofu wastewater is one of the most dangerous source of environmental pollutants. It is known that the COD of tofu wastewater can reach 8000 mg/L. Contact Glow Discharge Electrolysis (CGDE) method is an effective method in degrading complex pollutants contained in tofu wastewater, due to its ability to produce large quantities of OH radicals. This study aims to test the ability of the CGDE method in degrading the tofu wastewater by the addition air injection. In this method, several variations were made to determine the optimal airflow rate and initial concentration of tofu wastewater. Tofu wastewater degradation reached 73% for 120 minutes, with the final value of COD is 425 mg/L and BOD is 447 mg/L. Maximum conditions are obtained by using airflow rate 2.5 lpm, temperature 50°C, and initial concentration of tofu wastewater is 2000 ppm. The addition of air injection with airflowrate 2.5 lpm is able to reduce energy consumption by 37%. The results show that CGDE with air injection has the potential to degrade pollution parameter in tofu wastewater.
Study of domestic coal-based dimethyl ether (DME) utilization to reduce LPG import
Authors: Muliahati Annisa , Karamah Eva Fathul , Kaifiah Ika
Published: November 2018

This study evaluates the utilization of domestic coal-based dimethyl ether (DME) to substitute 15% of the total household sector demand of LPG import projected to year 2040 and the impact to the saving of state budget. Maximum LPG-DME blending in this study is 85% - 15% weight. DME-LPG mixture price at depot will be calculated based on DME FOB price at production plant, shipping cost, mixing and handling cost. The result of the research shows that DME-LPG mixture price and the import LPG price at each depot are 391 USD/MT and 620 USD/MT at Depot Tanjung Priok, 390 USD/MT and 620 USD/MT at Depot Eretan, 396 USD/MT and 622 USD/MT at Depot Tanjung Perak, 397 USD/MT and 622 USD/MT at Depot Gresik, and 401 USD/MT and 624 USD/MT at Depot Semarang. The substitution of LPG import with domestic coal-based DME results the saving of state budget about 388 million USD (IDR 5,332 billion). It concludes that the utilization of domestic coal-based DME is economically feasible to reduce the import of LPG per metric ton (MT), obtain the saving for state budget, and help the government to decrease the dependency of import LPG to maintain the national energy security.
Affordable and sustainable new generation of solar cells: calcium titanate (CaTiO3) - based perovskite solar cells
Authors: Torimtubun Alfonsina Abat Amelenan , Augusty Anniza Cornelia , Maulana Eka , Ernawati Lusi
Published: November 2018

Indonesia is located along the equator lines with the high intensity of solar radiation averaging about 4.5 kWh of electrical energy/day. This potential leads to the selfsustaining energy possibility fulfilling the electricity needs. Due to their unique electronic structures and high-cost merit over the existing commercial PV technologies, perovskite solar cells (PSCs) have emerged as the next-generation photovoltaic candidate. Their highest power efficiency can be achieved of up to 22.1% in the last 5-6 years. However, this high efficiency came from CH3NH3PbI3 materials which contain lead, a toxic material. Herein calcium titanate (CT) as a lead-free perovskite material were synthesized through sintering of calcium carbonate (CaCO3) and titanium oxide (TiO2) by the sol-gel method. CT powders were characterized by SEM, XRF, FTIR and XRD then applied it onto the mesoporous heterojunction PSCs, with a device architecture ITO/TiO2/CaTiO3/C/ITO. By manipulating the raw material stoichiometry and heating temperature in the synthesis of CaTiO3, the device shows the highest power conversion efficiency (PCE) of 2.12%, shortcircuit current density (JSC) of 0.027 mA cm-2, open circuit voltage (VOC) of 0.212 V and fill factor (FF) of 53.90%. This sample can be an alternative way to create lead-free, largescale, and low-cost perovskite solar cells.
CFD Simulation of Silica Gel as an Adsorbent on Finned Tube Adsorbent Bed
Authors: Kurniawan Andre , Nasruddin  , Rachmat Asep
Published: November 2018

The adsorption technology is becoming the more expected solution by today’s researchers for fix the energy and environmental issues. The main part of the cooling system adsorption is adsorbent and adsorbate. One of the most widely used adsorbents in research of adsorption technology is silica gel. A new silica gel-water adsorption chiller design was developed that composed of two sorption chambers with compact fin tube heat exchangers as adsorber, condenser, and evaporator. Energy, mass, and momentum conservation equations of the adsorption systems have been used for the CFD two and three dimensional models. The geometry of simulation is simply made within silica gel layer between two fins. The simulation is also implemented using a finite volume method through the CFD software Fluent. User defined functions are given to modify the energy, mass, and momentum conservation equations. The simulation of adsorption process is adjusted at unsteady condition. Adsorption and desorption processes are simulated with room temperature for cooling water inlet at temperature 305.15 °K, hot water inlet at temperature 353.15 °K, mass flow rate cooling water inlet at 0.3 kg/s and pressure 32 KPa. For the whole adsorbent bed area, the result shows that the highest absolute adsorption rate at the outer surface, while the lowest rate is at the center. After adsorption was finished, the condition is reversed. The highest absolute adsorption rate is achieved at center, while the lowest rate is achieved at the outer surface.
Overpotential evaluation of PEMFC using semi-empirical equation and SEM
Authors: Akimoto Yutaro , Suzuki Shin-nosuke
Published: November 2018

Fuel cells are a clean and weather-independent power supply. Solar and wind power are widespread in islands that are difficult to supply power. If problems are solved in the future, fuel cells are also expected to become popular. The widespread commercialization of PEMFC stacks depends on their reliability and fault diagnosis. In this study, we developed a degradation diagnosis method for the purpose of improving reliability. The output reduction of the fuel cell is separated into reduction factors called overpotentials. And the factor of the decrease is specified. In this paper, we show the proposed method and the degradation factors, and the effectiveness of the method.
The Use of Flow-Induced Vibration as An Alternative Resource of New Power Plant in Indonesia
Authors: Subekti  , Hammid Abdul , Surjosatyoe Adi
Published: November 2018

Considering the current energy crisis in Indonesia which is indicated by the depletion of oil reserve, the government believes that the existing power plants are not adequate to meet the electricity needs of this country. This can be seen clearly with the blackouts in many places in Indonesia. There are two economical methods to generate electricity on a large scale. First is by using hydropower and second is by using heat power. However, this cannot meet the needs of electricity in this country because of the difference in natural conditions in some places in Indonesia. Fluid flow and structure is an interactive system and its interaction is dynamic. This is a coupling system of forces to work on the structure generated by the surrounding fluid. The force of the fluid causes the structure to deform. When the structure is deformed, this means that its orientation to the fluid flow changes, so that, subsequently, the fluid force may change. This condition is called vibration phenomenon caused by flow. This experiment was conducted in Engineering Laboratory of Mercu Buana University Jakarta in 2017. The instrument of this study was the Wind Tunnel. This research aims to find out the flow-induced vibration that was affected by two parameters (flow velocity, the diameter of the kinematic fluid viscosity). These two parameters will get lift force and lift force, thus causing the generator to spin to generate electricity. The result of this research shows that the fluid flow has lift and drag force. The best result was obtained by specimen B velocity of 4.76. It also gave lift displacement of 20 mm. The success of the test depends on the election of spiral spring.
Simple method for I-V characterization curve for low power solar cell using arduino nano
Authors: Rezky Ananta , Devara Kresna , Wardana Nurian Satya , Ramadhanty Savira , Abuzairi Tomy
Published: November 2018

In general, solar cells properties were measured under standardized environment. Recent method uses a Solar Simulator or Sun Simulator to measure a solar cell characteristic by the condition of 1000 W/m2 irradiance and 25°C temperature. However, solar simulator is expensive, therefore in this paper we propose a simple I-V characterization method with microcontroller, potentiometer, and sensors to measure I-V characterization of solar cell. Our method used a microcontroller to record any detected current and voltage from sensors generated by the solar cell driven by halogen light on low power poly-Si solar cell. This method is limited by the sensor rated voltage and current, thus a higher power solar cell is possible to be measured with a higher rated voltage and a current sensor for the future development. The measured Voc and Isc of 3 Wp poly-Si solar cell have 1.94% difference in Voc and 49.1% difference in Isc against the standardized environment. This method is able to characterize a low power solar cell with slight difference on Voc and about half value of Isc compared to standardized I-V curve characterization due to the limitation of halogen lamp spectral irradiance.
Coaxial dielectric barrier discharge plasma reactor for biodiesel production from palm oil and methanol
Authors: Fakhri Saphira Nurina , Ramadhani Sari Dafinah , Bismo Setijo
Published: November 2018

Biodiesel is one of renewable energy alternatives, as a substitution of diesel engine fuel or diesel oil. Indonesian palm oil contains the fatty acids needed for the synthesis of FAME (fatty acid methyl ester) as the basic ingredient of biodiesel. Conventional biodiesel synthesis methods, which generally use transesterification reactions with homogeneous and heterogeneous catalysts, have significant constraints due to the formation of relatively large quantities of glycerol compounds as well as requiring complex separation processes and considerable energy. The DBD (Dielectric Barrier Dicharge) plasma reactor can be a solution to overcome the above shortcomings. The purpose of this research is to perform performance test from design result of DBD plasma reactor especially biodiesel making process. The analytical methods for FAME products use GC-FAME and FTIR (Fourier Transform Infra Red) for chemical conversion related between triglyceride reactants and biodiesel products. The best operating conditions obtained from the hydrodynamic test showed a mixed flowrate of triglyceride/alcohol of 0.1318 L/min, gas flowrate (plasma carrier) of 2.5 L/min and a voltage of 220 Volts alternating current. Biodiesel is produced using palm oil and methanol as a liquid reactant and using argon as a plasma carrier gas in the reactor. Plasma is produced in DBD reactor using 1-phase PLN power, with a voltage of 220 VAC. The main advantage of the conversion process in this plasma reactor is the production of FAME without the formation of significant glycerin byproducts and the use of homogeneous or heterogeneous catalysts.
Effects of aeration intensity as agitation in simple photobioreactors on leptolyngbya (cyanobacteria) growth as biofuel feedstock
Authors: Orlando Aliff Muhammad , Ardiansyah Sulthan Rafii , Rahman Arif , Prihantini Nining Betawati , Nasruddin
Published: November 2018

Indonesia known as a hotspot of biodiversity, including cyanobacteria biodiversity. One member of cyanobacteria (prokaryotic algae) is Leptolyngbya. Leptolyngbya HS-16 is an isolate that had been isolated from hot spring in Red Crater of Gunung Pancar, Sentul, Bogor. As mats-producing microalgae, this strain is a very promising source of Biofuel. Biofuel can be extracted from lipid of microalgal biomass. Bioreactor is a method to encourage the growth of microalgal biomass. To get a best result in growth, agitation must be done, to make sure every single cell of microalgae gets the adequate nutrition. The aeration on simple photobioreactors is set to high and low intensity. The high intensity of aerations average amount are 191 bubble/min, while the low intensity one are 117 bubble/min, with a device that could produce smaller bubble size to reduce the aeration-agitation effect. The research was done to acknowledge the effect of aeration intensity to Leptolygnbya HS-16.
Applied voltage optimization for denitrification process improvement by denitrifying species of Pseudomonas in microbial electrolysis cell (MEC)
Authors: Ekadewi Putty , Hardhi Matthew , Puspitarini Putri Anggun , Istiqomah Hidayati , Gomez Cristina , Arbianti Rita , Utami Tania Surya , Hermansyah Heri
Published: November 2018

Denitrification is the conversion process of nitrate to gaseous nitrogen forms carried out by bacteria commonly referred to as denitrifiers. Microbial Electrolysis Cell (MEC) is a type of bioelectrochemical system (BES) that is connected to external power source to aid the reactions. This research investigates the effect of applied voltage value on denitrification by nitrate removal efficiency of two model denitrifying species from the genus Pseudomonas in single-chambered MEC. Pseudomonas aeruginosa and Pseudomonas nitroreducens exhibited native removal efficiency at 70.62% and 68.20%, respectively. These values respectively reached up to 89.67% and 88.58% at 1.20 V, the upper limit of this study. Pseudomonas aeruginosa displayed better performance in MEC based off its produced current stability (mA) across the 0.35-1.20 V range. The effect of applied voltage on nitrate removal efficiency and setup performance was more prominent on known exoelectrogenic species of Pseudomonas such as Pseudomonas aeruginosa compared to Pseudomonas nitroreducens. Operating applied voltages of 0.35 V and 0.70 V was recommended for the application of the system based on technical and economical considerations. Further studies are needed to determine the response of the bacteria on wider range of applied voltages in MEC as well as elucidating these effects on autotrophic systems.
Burner Design for biogas-fuelled Stirling engine for electric power generation
Authors: Yatim Ardiyansyah , Luthfi Ade , Chemilo Raden
Published: November 2018

The Stirling engine is an external combustion where the fuel combustion process takes place outside the cylinder, at the combustion chamber or burner. Stirling engine offers flexibility of fuel used for the power generation hence is a potential substitute to fossil fuelled internal combustion engine and contribute toward more sustainable power generation. In this study a burner for Gamma V2-6 Stirling engine is designed and developed for a biogas-fuelled power generation system. The heat used to power the Stirling engine is obtained from combustion of biogas at the burner. The system has 5 kW capacity fuelled by 165 kg/day solid waste (biowaste) from local farm. The bio-digester needed is 20 m3. The combustion temperature of the burner is in the range of 600 to 1000°C. The required fuel input is 60,000BTU/hr or equivalent to 17 kW. The system requires constant heat from the combustion chamber hence a specific burner is designed to fulfil the purpose and accommodate biogas composition and optimum heat transfer to the engine. The burner is able to provide for simultaneous air preheater for lower fuel consumption leading to 37% lower fuel consumption.
Field testing and evaluation of a domestic biomass cookstove in rural small household industry
Authors: Suhartono  , Suharto  , Agustina Nurlaila , Hafidaturrohmah Hanna
Published: November 2018

This work presents the performance parameters of a solid biomass cookstove for household industrial application to meet the parameters required by the National Standardization Agency of Indonesia (SNI 7926: 2013). The biomass stove design was tested using corncob, coconut shell and wood chips as biomass fuel. Thermal efficiency, combustion efficiency, specific fuel consumption, emission of CO and particulate emissions were evaluated. The combustion temperature, visual flame, combustion air requirement as well as economic evaluation were also studied as additional performance parameters. The average specific fuel consumption rate, Sc of the stove was found 0.57 kg/h. The using amount of biomass variety on this stove could produce the maximum thermal power, Pth of 24,75 kWth and the average combustion efficiency, ηc and the thermal efficiency, ηth of 98.2% and 27%, respectively. The flame temperature of 722-947°C was achieved at equivalence ratio, ф=0.61-0.89. The average CO and particulate production, PM2.5 on this biomass stove were 39.97g/kg and 0.9 g/kg, respectively. The difference of profit margin compared to liquid petroleum gas (LPG) utilization as fuel was about IDR 2,000/kg fish. All these parameters are met to SNI 7926:2013 and corncobs seem the most appropriate biomass fuel on the consideration of this test results.