bluuebunny/crossref_metadata_2025 huggingface dataset:
Drivability analysis based on the mathematical model of soil flow resistance
Authors: Widjaja B , Utama R , Saerang D S S
Published: November 2019

When a pile is driven, the soil around the pile reaches a critical condition. This results in a failure condition for the soil, which then moves as a viscous element. The flow is caused by the external driving force exceeding the static resistance of the soil. When the failure condition is reached, the dynamic resistance of the soil will counter the penetrating force of the pile. The rheology model is accurate in representing the soil flow when the critical condition is reached, because the parameters used for the mathematical model of soil flow resistance represent static and dynamic resistance. The dynamic resistance is influenced by the shear viscosity of the soil, which was determined using the Bingham and Casson models. Discrepancy exists between the analytical output used in the mathematical model of soil flow resistance and the actual result. Therefore, a correction factor is needed to calibrate the displacement of the pile.
Study on tropical organic soil stabilization based on biogrouting
Authors: Widjajakusuma J , Sugata M , Changgrawinata A , Jap L , Zacharia A , Tan T J
Published: November 2019

Biogrouting is a new environmental friendly stabilization method to stabilize soft soils by applying microorganisms. The microorganisms produce CaCO3, which fill voids of soil particles and bond the particles. This work studied biogrouting of high plasticity tropical organic soil applying Bacillus subtilis bacteria. In order to study the effectiveness of biogrouting using Bacillus subtilis, unconsolidated undrained triaxial and direct shear tests were conducted on the untreated and stabilized soils. The curing time for the stabilized soil specimens were 7, 14 and 28 days before the tests were conducted. In order to study the influence of the amount of Bacillus subtilis, 6 ml and 12 ml of Bacillus subtilis liquid culture was injected into the soil specimens. The soil became stronger as the amount of Bacillus subtilis used increased. The results indicated that the longer curing time and the higher amount of Bacillus subtilis reflected better soil improvement in term of cohesion, friction angle and shear stress. After 28 days of curing time, injection of 6 ml and 12 ml Bacillus subtilis liquid culture increased the effective stress cohesion values by 180% and 270%, respectively.
Identification of types and important value of aquatic vegetation and their potential to improve water quality in irigation canals of Mulyasari Village, Banyuasin District
Authors: Yuanita Windusari , Septiani Wiwik
Published: November 2019

Irrigation has an important role as a source of irrigating rice fields. Irrigation water is often contaminated by waste from anthropogenic activity. Indications of pollution in irrigation channels because the use of pesticides or other chemicals in agricultural land can be observed based on the number and type of vegetation that grows in the irrigation canal. Vegetation that grows in these waters is also believed to have the potential to improve the quality of water as phytoremediation. This study aims to determine the characteristics of vegetation, identify species that grow around the irrigation canals, and calculate the importance of aquatic and riparian vegetation in the irrigation channels of Mulyasari Village, Banyuasin Regency and analyze the potential of aquatic and riparian vegetation. to improve water quality. The method used to determine the station in this study is purposive sampling method. Vegetation analysis was carried out at 4 station points, research was conducted at low tide.. A bamboo quadrate plot having measurement of 1m x 1m with a perpendicular stake is used for data collection on aquatic vegetation, its type is observed and recorded. The results of the study found 6 types of vegetation, namely: Eleucharis dulcis, Hydrilla verticillata, Nymphae alba, Swersia hexandra Sw, Eleucharis acicularis, and Eleusine indica. Aquatic vegetation is dominated by flowering vegetation with linear leaf type. This study also shows that aquatic or riparian vegetation such as Eleucharis acicularis are the species that dominate canal waters with the highest Important Value Index is 46.51-81.22%, while Eleusine indica is a type of vegetation that tends to be rarely found (the average important value index is 10.86-19.84 %). Based on this, it was concluded that aquatic vegetation such as Eleucharis acicularis, which was found in the irrigation channel was the dominant vegetation in the canal. This vegetation has the potential as a phytoremidiation agent because of its role in maintaining the balance of the aquatic ecosystem so that it can improve the quality of water and can also be used as organic fertilizer, biofilter, and absorbent toxic elements. Eleucharis dulcis can improve the quality of water during the dry season by absorbing toxic dissolved ompounds.
Analysis the Potential of Fire and Explosion at Secondary Reformer as Processing Unit in Ammonia Plant
Authors: Lestari R A , Rodhiyah Z , Fitrada W , Handika R A , Oginawati K
Published: November 2019

Increasing of fertilizer industry in the world made the increasing of ammonia industry as well. Ammonia was used as nitrogen source in fertilizer industry. Ammonia process production involved natural gas (flammable) with high temperature and high pressure in the process. Secondary reformer was the one of process unit plant in ammonia plant that had high temperature and pressure. Secondary reformer was the one of the unit process used to get hydrogen (H2) from natural gas. Hazard identification for secondary reformer was conducted by using Fault Tree Analysis (FTA). The results of FTA analysis for secondary reformer could be grouped into technical and non technical aspects. Non technical aspects had 76% possibility in fire/explosion at secondary reformer. Analysis using Dow’s Fire & Explosion Index (DFEI) resulted that the radius effect due to secondary reformer explosion was 74 meter. The actual probable property damage was US$ 11.649.269 and probable daily outage at least 129 days. Software ALOHA (Arial Location of Hazardous Atmospheres) resulted that the lowest effect of secondary reformer explosion, 0,5 psi, that could shattered the glass was 62 m in radius. Moreover, the radius effect for 1 psi explosion strength (made house/office inhabitable) was 41 m from secondary reformer.
The effect of gypsum plafond waste on shear strength of soft clay soil
Authors: Rustam Reffanda Kurniawan , Resti Ayu , Purwanto Herri , Muhammad Firdaus
Published: November 2019

One type is soft clay soil which has a low compressibility and high water content that causes the carrying capacity of the soil to be low. In this research, soil improvement was carried out chemically by soil stabilization method using a mixture of gypsum plafond waste with a percentage of 5 %, 10 %, 15 %, 20 %, and 25 % in a laboratory scale. Soft clay samples used for the study were taken in the Pakjo area of Palembang, South Sumatra. The use of gypsum plafond waste as a mixture was expected to increase the shear strength of soft clay. Tests carried out include testing Direct Shear. Based on the USCS classification, the soil was classified as CH and based on AASHTO classification was A-7-6. The value of wop is 22 % (optimum moisture content) and the value of γdmax is 1.74 gr/cm3 (maximum dry weight). The maximum cohesion (c) value is 24.20 kPa from 15 % mix of gypsum plafond waste (WPG15) sample. For the maximum value internal friction angle (ϕ) is 16.36 °C from 5 % mix of gypsum plafond waste (WPG5) sample. The maximum shear strength (τ) is 26.57 kPa from 5 % mix of WPG15 sample.
Mechanical properties analysis of reactive powder concrete with curing temperature variation
Authors: Saloma  , Hanafiah  , Agistin Veriza
Published: November 2019

A Reactive powder concrete is one of Ultra High Performance Concrete developed through microstructure repair. This research uses silica fume and steel fibre with w/c = 0.23. The curing temperature variations used in the study were 27°C, 60°C, 90°C, and 120°C. Testing methods slump flow, compressive strength, modulus of elasticity, tensile strength and flexural strength were performed based on ASTM and ACI. This research shows that the compressive strength, modulus of elasticity, tensile strength and flexural strength are directly proportional. The optimum temperature of the study was 90°C. The compressive strength and maximum modulus of elasticity this study were 111.43 MPa and 51,400 MPa at curing temperature of 90°C. Tensile strength and maximum flexural strength in this study were 6.19 MPa and 10.82 MPa at curing temperature of 90°C.
Experimental investigation of long interlocking brick column subjected to eccentric load
Authors: Hao Yew Zhi , Saggaff Anis , Tahir Mahmood Md , Ngian Shek Poi , Sulaiman Arizu
Published: November 2019

The Industrialized Building System (IBS) is referred as advanced construction technique which involved the prefabrication of construction components in controlled environment and then installed on site. It promotes faster, neater, safer, easier and cheaper construction works in future. Interlocking Brick (Blockwork System) is one of the IBS which has not commonly known in Malaysia. The key objectives of this research are to investigate the compressive strength of long interlocking brick column with cement mortar and SikaGrout®-215 filler under concentric and eccentric load, in addition to study its failure mechanism and compare the experimental result with existing design code. Four number of 2.3 -meter height column was built by using interlocking brick with Y12 steel bar and different filler and performed compressive strength test and the result is compare with the existing design code which is Eurocode 2 and BS 8110. From the research, Interlocking brick column with cement mortar filler had lower compressive strength capacity compare to column with SikaGrout®-215 under concentric and eccentric load. In term of failure mechanism, the column samples were failed by sudden crushing of interlocking brick. For column sample with grout, the percentage of difference of BS 8110 and Eurocode 2 modified equation compare to the experimental result is 10.20% and 12.56% respectively under concentric load. Moreover, for column sample with mortar infill, the percentage of difference is 67.16% for BS 8110 and 73.23% for Eurocode 2. For eccentric load, Eurocode 2 did not provide reasonable agreement where the percentage difference is range from 66.40% to 482.47%. The optimum design of interlocking brick column in this study is the column sample with SikaGrout®-215 as it has higher compressive strength compare to Type M cement mortar.
Mapping of Municipal Solid Waste Transportation System, Case Studies Seberang Ulu Region Palembang City
Authors: Putri Septi Rika , Muda Khalida Binti , Alia Febrinasti
Published: November 2019

One of the human activities that affect the state of the environment is the domestic waste disposal. Palembang with economic growth and rapid population does not have adequate solid waste management, which is characterized by wild rubbish heaps in several locations, one of which is in the region Seberang Ulu. The results of this study show that the volume of solid waste generated in the research area by 2.98 liters/person/day. In planning for the needs of solid waste transportation systems, solid waste reduction activities such as solid waste bank unit and the 3R system (TPS 3R) need to be considered, with a target of solid waste reduction was 20%. Solid waste reduction can ultimately extend the life of the landfill. Projected needs garbage container (capacity 6 m3) and garbage trucks (capacity 8 m3 with 5-6 rit/day) in 2027 was 166 and 25 units, with the requirement of solid waste reduction in solid waste bank and 3R unit 29.93 m3/day. The volume of solid waste generated is directly proportional to the increase in population, and solid waste reduction greatly influenced the community’s active role as a producer of garbage.
Improvement of the raw drinking water quality from shallow well by ozone treatment
Authors: Helmy Qomarudin , Notodarmojo Suprihanto
Published: November 2019

The interests of ozonation has increased significantly in recent years and today the ozonation is used in other steps in the drinking water treatment process. Ozonation has been used in the refill drinking water depot in the region of Indonesia for several years as disinfection at the end of the drinking water treatment process. Except for the disinfection, ozone has other benefits such as oxidation of iron and manganese, micro flocculation, reduction of taste and odour and it is also effective to reduce the water colour. The micro flocculation leads to the fact that less or no coagulants need to be used in the process. This study started with a lab scale experiments on ozonation and filtration of raw drinking water taken from shallow well followed by examination in the pilot plant. Research result showed the removal efficiency for organics, iron, manganese, and turbidity is up to 75 %; 98 %; 85 %; and 98 % respectively. All the parameter is comply with the drinking water standard regulated by Indonesia Ministry of Health No. 492/Menkes/PER/IV/2010. Disinfection capability of ozone against microorganisms will be reported in the full paper.
Cyclic behaviour of expanded polystyrene (Eps) sandwich concrete walls
Authors: Wibowo Ari
Published: November 2019

Precast concrete walls become increasingly utilized due the rapid needs of inexpensive fabricated house especially as traditional construction cost continue to climb. Moreover, particularly at damaged area due to natural disaster when the requirement of a lot of fast-constructed and cost-efficient houses are paramount. However, the performance of precast walls under lateral load such as earthquake or strong wind is still not comprehensively understood due to various type of reinforcements and connections. Additionally, the massive and solid wall elements also increase the total weight of building and hence increase the earthquake base shear force significantly. Therefore, the precast polystyrene reinforced concrete walls which offers light weight and easy instalment became the focus of this investigation. The experimental test on two RC wall specimens using EPS (Expanded Polystyrene) panel and wire mesh reinforcement have been conducted. Quasi-static load in the form of displacement controlled cyclic tests were undertaken until reaching failure. At each discrete loading step, lateral load-deflection behavior, crack propagation and collapse mechanism were measured which then were compared with theoretical analysis. The findings showed that precast polystyrene reinforced concrete walls gave sufficient seismic performance reaching up to 1% drift at failure point against lateral.
Structural perfomance of cold-formed wall frame under combined gravity and lateral loading
Authors: Ngian Shek Poi , Thong Lim Teck , Tahir Mahmood Md , Saggaff Anis
Published: November 2019

Light steel framing is generally based on the use of standard C or Z shaped steel sections produced by cold rolling from strip steel, which is normally refers to cold formed steel sections. Light steel framing is already well established in residential construction in North America, Australia and Japan. Cold formed steel sections are widely used in many sectors of construction, including mezzanine floors, industrial buildings, commercial buildings and hotels and are gaining greater acceptance in the residential sector. In Malaysia, cold formed steel sections are frequently use in roofing systems such as roof trusses and purlins. The light steel framing system has yet to be practiced in Malaysia. There is a need to investigate the economic aspects of the light steel framing system in our local industry, conduct comprehensive testing and parametric studies to create the guidance and procedures of the analysis and design of such building. This paper presents a lightweight system for wall panels made of cold-formed steel sections. Three wall panel samples are tested experimentally under combined gravity and lateral loading to investigate the performance of the panel in terms of strength, stiffness and ductility. The results from the experiments show the wall panel using back-to-back and box arrangement able to increase the lateral stiffness and strength as compared to single section wall panel. The increment of strength can goes up to 39% under combined gravity and lateral loading while for lateral stiffness the increment can goes up to 83%. The performance of the panel can be applied to the light steel structure that can materialize the new residential building mode of low cost, high efficiency and large scale. The significance of this study is to reduce the use of labour by introducing pre­fabricated panel section, which is environmentally friendly and reduce congestion on site, and able to reduce overall construction cost by using precast construction with higher strength and stiffness capacity.
Issues of shear deformation measurement in experimental studies
Authors: Basyaruddin  , Cheng Min Yuan
Published: November 2019

Shear deformation determined using “X configuration method” as traditional instrumentation plan is controversial. Shear deformation of two specimens was re-investigated in this research. One of those (SP3) was representing a RC beam member using a single curvature test scenario and a coupling beam specimen (CB2) was representing a RC beam member using double curvature test scenario. The new instrumentation technology, optical system, provides a useful tool to evaluate different traditional instrumentation plans. Shear deformation is evaluated with different gauge lengths. The best-possible solutions of both specimens are determined using the optical system with the finest grid. Error is estimated by comparing results from “X Configuration” method with the best-possible solution. Analysis results indicate that the smaller gauge length yields the better results. A gauge length of 6.3 in. (160 mm) from X configuration method gives the smallest error, less than 10 %, in measuring shear deformation in a flexural governed member. It suggests that the gauge length to \measure shear deformation in a coupling beam specimen can be limited within 16.5 in. (420 mm). The largest gauge length from X configuration method in measuring shear deformation shows the largest error for both specimen SP3 and specimen CB2.
Evaluation of Handover Practice in Post-disaster Reconstruction in Aceh Province, Indonesia
Authors: Adamy Aulina , Bakar Abu Hassan Abu , Razak Arman Abdul
Published: November 2019

As the largest reconstruction project in the developing world at the time, Aceh’s post reconstruction experience may provide useful lessons on how aid is delivered particularly for public buildings and facilities as one of the largest amount of projects after housing. In Indonesian construction industry, among many stages of construction process, handover is still commonly underrated or even skipped. This is no different in the case of post-disaster reconstruction where challenges raised as there were pressures to build thousands of facilities in a limited amount of time and need to be occupied as soon as possible. This study objective is to evaluate the handover practice in post-disaster reconstruction of public buildings and facilities after being occupied. The survey focused only for buildings constructed by the Indonesia government agency (BRR) and managed to cover 24 buildings that are divided into government offices, schools and community health centres in Banda Aceh, the capital city of Aceh province from total 53 buildings available. Questionnaires were distributed to respondents which are government staff that responsible for the building operational with a response rate of 54%. The survey results show that the handover process is not completed and therefore the respondents doubt with the building quality. Though, respondents are neutral in accepting buildings without proper handover because they understand the urgency of operating public buildings and facilities immediately in emergency situation. Respondents still urged for post-occupancy evaluation by independent committee and fully agreed for proper handover practice in the future. As for final recommendation, conducting project evaluation by independent committee is essential even most of the buildings already being used and might replace the lack of handover administration stage for legal solution in government assets in the context of Aceh’s post-reconstruction.
Potential Use of Municipal Solid Waste Ash (MSWA) As Sustainable Construction Bricks
Authors: Saleh Ani Maslina , Rahmat Mohamad Nidzam
Published: November 2019

Uncontrolled infrastructure development may produce excessive carbon emission and scarcity of natural resources, that exploited for the mean of development. The reuse of waste materials will promote material ecology and the cradle to cradle concept. This study utilizes Municipal Solid Waste Ash (MSWA) as a potential target material in replacing laterite soil that is nonrenewable natural resources. Mix design, compositions were established for industrial trial of brick making. Laterite soil on its own (100%) and in combination with MSWA, (50:50) stabilized with PC and Lime at 20% and 30% were used to produce bricks. The bricks were then air dried. Two engineering properties, compressive strength and water absorption were studied. The investigation results show that compressive strength and water absorption of laterite soil combine with MSWA at (50:50) recorded higher strength compared to when laterite soil were used alone. This suggests viability and feasibility of using waste material in brick making.
The User Requirements for Building Maintenance Management Systems in Malaysian Public Universities
Authors: Zakiyudin Mohd Zulakhmar , Fathi Mohamad Syazli , Rambat Shuib , Tobi Siti Uzairiah , Rajab Nor A’ini
Published: November 2019

Representing almost 50% of the total turnover of construction activities, building maintenance investment is huge all over the world. In facilities management activities, building maintenance is also regarded as a common function. This paper emphasises the current user requirements for building maintenance management in Malaysian public universities. Starting with semi-structured interviews, information gathered focuses on different aspects of building maintenance practice to identify the main user requirement issues. The areas of study are to justify the objectives of maintenance departments and examine the processes of maintenance reporting and verification and other associated tasks. In this study the applications and contributions of Information Technology (IT) facilities in maintenance practices are reviewed. Finally, the development of user requirements by using the interface design concept is explored. It is envisioned that, in the future, good building maintenance practices will become the norm in Malaysia so that users will extract maximum benefits from their buildings and facilities.
Energy Efficiency Criteria for Common Building Structure Systems: An Overview
Authors: Balubaid S. , Zin R. M. , Hassan J. S. , Mardzuki Samihah
Published: November 2019

Making decisions about the selection of energy efficiency building construction is one of the sustainable construction key. Therefore it is crucial to identify criteria that can influence the choice of energy efficient common building structure systems. The main purpose of this paper explores the energy efficiency criteria for common building structure systems. Thus, the paper adopts a conceptual approach by using current literature on energy efficiency. The paper shows a wide range for the energy efficiency criteria for common building structure systems. This range in reported figures is due to the use of common different building structure systems through different LCA methodologies and different boundaries. For that reason, this paper contributes to the literature by providing deeper insights into the energy efficiency criteria influencing the selection of energy efficiency common building structure systems. The paper also present a new approach that will support energy efficiency termed ‘energy efficiency common building structure systems’. And this will opens several interesting avenues for future research.
Study on Energy Consumptions for The Commercial Buildings Using Energyplus
Authors: Abu Bakar Mohd Noor Ropiah Bin , Yahya Khairulzan Bin
Published: November 2019

This paper presents the results of simulation for commercial building using Energyplus program and ASHREA database. The study is concerned on the factors that can enhance the energy efficiency in the existed building where there are a limited possibility in comparison with the new buildings. The construction of the building has been drawn in Sketch up 8 and the calculation has been made in energyplus however the communication between them has been accomplished using legacy open studio. The ASHREA database used in this paper is related to Kuala Lumpur region where there is no database for Johor in such organization. Three factors has been studied now: increasing of daylight control sensors, increasing the cover shadow of windows, effect of presence of trees infront of the buildings. The results show that there are a significant effects to the total energy used in the building with improving the above factors and therefore the energy efficiency is increased.
Comparative Analysis of Material Fluctuation Response based on Data Set Groups
Authors: Melinda Melinda , Sianturi Patar , Tamsir Agus Santoso
Published: November 2019

Multi spectral capacitive sensor (MSCS) is a sensor that is formed based on the concept of white noise impedance spectroscopy. This concept utilizes the spectral noise frequency approach of the frequency domain signal resulting from the field effect on the dielectric. As a sensor, the consistency results obtained is stable, so that it can facilitate analysis. In this study, we tried to compare data groups, starting with 100 data sets and 300 data sets from a total of 600 data sets for H2O and H2O mixed with NaOH materials and H2O mixed with HCl using a new transformation, namely Tamsir statistical transformation (TST). Furthermore, grouping data uses the total amplitude value of each data set obtained. We obtain the results in the form of differences between groups of data with fluctuations in response patterns that are close together which are shown in 2D graphics. Hence, we can implement the data groups as a reference pattern of fluctuations in a material.
MIMO 4×4 hexagonal microstrip array antenna for 15 GHz application
Authors: Nur Levy Olivia , Aji Alvian Raharjo , Syihabuddin Budi
Published: November 2019

Recently 15 GHz has been a frequency candidate for fifth generation (5G) mobile communication technology. Minimum bandwidth has to provide for 5G application is 1 GHz. In this paper we proposed antenna design to fullfill those requirement. We use microstrip patch antenna which has narrow bandwidth. To improve the bandwidth, we use proximity couple and observe the hexagonal patch antenna frequency response. We design a 4×4 MIMO antenna with less than -15 dB return loss and -20 dB mutual coupling to each ports. From the realization we have maximum bandwidth 1.34 GHz with lower frequency 14.42 GHz and upper frequency 15.76 GHz.
The 4×4 hybrid L-slotted rectangular microstrip antenna for dual band wifi communication
Authors: Agusta Ramaska Prima , Wijanto Heroe , Syihabuddin Budi , Prasetyo Agus D.
Published: November 2019

Indonesia has regulated 2.441 GHz and 5.8 GHz bands for WiFi communication. Considering these two bands requirement, L-Slot can be added into a rectangular microstrip antenna. Then, we transform the single dual band antenna into MIMO to increase the system capacity and reffering the a WiFi specification. In this study, the designed 4×4 hybrid L-slotted rectangular microstrip antenna can produce: bandwidth ≥ 40 MHz for 2.441 GHz and ≥ 100 MHz for 5.8 GHz (using return loss ≤ 10 dB), and obtained mutual coupling ≤ -20 dB. The radiation pattern produced for both of 2.441 GHz and 5.8 GHz is unidirectional.
Numerical and experimental study on Solar Updraft Power Generator (SUPG)
Authors: Ridwan Abrar , Abdurrahman Ridwan , Fauzi M Ridha , Nusbir Yohanes , Anggraini Denny
Published: November 2019

The need for energy is fundamental to drive the economy and social from the community. Clean, renewable, and sustainable energy is the one desired by the community today. Solar Updraft Power Generator (SUPG) is one power generation system that utilizes heat from solar radiation to produce artificial wind that will drive the wind turbine. This study consists of numerical and experimental analysis. The numerical analysis uses ANSYS 17.2 and SOLIDWORKS 2016. SOLIDWORKS 2016 is the software used in designing SUPG geometry. ANSYS 17 is the software used to analyse SUPG velocity and temperature contour. Then the numerical analysis would be compared with the experimental analysis. The study took place on a SUPG the laboratory conversion energy of the Muhammadiyah University of Riau. From the numerical analysis we can conclude that the higher ΔT ground-ambient would resulting a higher air velocity. Compared numerical to experimental analysis showed a difference. For numerical analysis from ΔT ground-ambient 5°C resulting maximum velocity 1.6 m/s, while for experimental analysis from average ΔT ground-ambient 3.6°C resulting maximum velocity 4.1 m/s. This happened because there still much external force (such as wind) that increase the velocity that generated inside the Solar Updraft Power Generator beside the buoyance force.
Effects of varying chemical composition with x = 0.1 – 0.7 on magnetic properties of soft ferrite Ni1-xZnxFe2O4
Authors: Idayanti N , Dedi  , Kristiantoro T , Sudrajat N , Mulyadi D , Gustinova A
Published: November 2019

The preparation of NiZn ferrites with varying composition have been synthesized by mechanical milling method. The starting iron oxide (Fe2O3), nickel oxide (NiO), and zinc oxide (ZnO) were mixed with seven compositions of Ni1-xZnxFe2O4with x = 0.1 – 0.7. The effects of the composition on the structural and magnetic properties of the ferrite have been investigated. Structural properties were observed by X-ray diffraction (XRD) (Bruker’s). XRD patterns match well with the characteristic reflections of f d-3 cubic spinel structure, and it confirms that the all samples have single phase. Magnetic properties characterized by Permagraph Magnet Physik at room temperature. Hysteresis curve results show that varying composition influence the magnetic properties. Sample that have the highest Ms andMrvalues is when x = 0.3 with magnetization of remanence (Mr) = 30.1538 emu/g, magnetization of saturation (Ms) = 39.1642 emu/g, coercivity (HcJ) = 0.3040 kA/m, and density = 4.40 g/cm3. The highest HcJ value when x = 0.2, coercivity (HcJ) = 0.4050 k/m.
The effect of Lead (Pb) Hot dipping on seawater corrosion rate in ASTM A36 Steel
Authors: Eka Utami Nurhabibah Paramitha , Ellyanie  , Nasution Jimmy Deswidawansyah
Published: November 2019

Corrosion attacks are a scourge on offshore industrial structures. The hot dipping method is a common method used in protecting submerged material from corrosion attacks. The main objective of this study was to investigate the effect of variations in hot dipping time in Lead (Pb) on corrosion attack by performing corrosion rate test, weight loss measurement, microstructure analysis and fatigue test. The results revealed that the longer the hot dipping was carried out there was a decrease in the value of corrosion rate and weight loss of ASTM A36.
Passion-fruit shell biomass as adsorbent material to remove chromium III from contaminated aqueous mediums
Authors: Campos-Flores G , Gurreonero-Fernández J , Vejarano R
Published: November 2019

The aim of the study was to evaluate an adsorbent material based on passion-fruit shell biomass (PFSB) for chromium III removal from contaminated aqueous mediums, composed of distilled water and different concentrations of Cr(III), with a dose of 5 g of PFSB per liter. The residual concentration of Cr(III) in the treated mediums was determined by Atomic Absorption Spectrophotometry. A good adsorption process was carried out, achieving removal levels up to 85, 80, and 53% for solutions of 20, 50 and 200 ppm of Cr(III), respectively. The results showed an adequate fit to Langmuir and Freundlich models (R2 of 0.8864 and 0.7596, respectively), obtaining the following parameters qmax
: 27.933 mg g−1and b: 0.029 (for Langmuir model), and k: 1.400 and n: 1.650 (for Freundlich model), with a good adsorbent-adsorbate interaction for Cr(III) according to FT-IR spectra. Therefore, the obtained results suggest that Cr(III) can be removed by more than 50% by using passion-fruit shell, which with a minimum treatment could be used as an adsorbent in the treatment of chromium-contaminated aqueous mediums.
Sales prediction of Four Wheelers Unit (4W) with seasonal algorithm Trend Decomposition with Loess (STL) in PT. Astra International, Tbk
Authors: Telaga Abdi , Librianti Anggun Fadhlin , Umairoh Umairoh
Published: November 2019

Corporate Information System and Technology (CIS&T) division in PT Astra International Tbk is digitizing all business lines. Therefore, the company started to utilize machine learning to predict four wheelers (4W) sales in 2017. Data used were car sales data from 2014 to 2016. The data were obtained from company’s data warehouse (DW). Further, to develop application, firstly, Minitab was used to compare algorithm in modelling phase. Then, Azure Machine Learning Studio (Azure ML) was utilized to build prediction model based on algorithm chose in first phase. Finally, visualization was developed using Power Business Intelligence (Power BI). Time series algorithm used to solve the case is Seasonal Trend Decomposition with Loess (STL). While, machine learning model uses R library, and process flow module in Azure ML. The STL prediction model yield 9.38% error. Visualization of result is divided into two sections filtered by three parameters type, color and area. The first section in dashboard is sales data report showing percentage of type, color of cars and deployment of 4W units in Indonesia through ArcGIS Maps. The second section is forecast result containing chart of x axis to represent year and y axis to represent number of units. Further, the chart provide historical, current and forecast information. The research contributes to illustrate development of prediction using machine learning in industrial environment.
Series and parallel relationship pump performance in FT. Unitas’s practicum tools
Authors: Intang Ambo , Dwipayana Hendra
Published: November 2019

Basically, the variation of the pump arrangement in the piping installation is done to get the performance / flow characteristics needed in a particular usage according to the needs, namely the need for a head height that is higher than the flow rate (capacity) or vice versa. Flow regulation method with variations of valve openings (Senen 2004), which is applied in this study with consideration of energy use efficiency, it can be stated that the pump efficiency range of the parallel circuit is high to get a larger flow rate than the series circuit pump. To get the head maximum, the pump efficiency series is smaller than the pump efficiency of the parallel circuit, so that it does not provide an illustration that the optimum pump work has been achieved, so that further research needs to be carried out research with variations in pump rotation (Mastur and Warso 2015) below or above the standard round. But based on the purpose of this study in terms of pump performance, to meet the needs of a high head, the pump installation is arranged in series and vice versa if what is needed in the pump installation system is a high flow rate, the pump is arranged in parallel, so the results of this study have been can meet the needs of practicum for students of Mechanical Engineering Study Program FT. Unitas in terms of how to get the performance of a centrifugal pump installation.
The prediction of fatigue crack growth of rotary kiln shell welded under cyclic loading
Authors: Basri Hasan , Yani I , Yanis M , Prakoso A T
Published: November 2019

In this paper, fatigue crack propagation in the kiln shell welded under cyclic loading has been estimated using computerized finite element analysis (S-Version FEM). By using the S-FEM technique, it makes the local mesh which is re-meshed automatically, then it becomes easier to make a numerical study of crack growth on the welded kiln shell. Virtual crack closure integral method (VCCM) uses the stress intensity factor evaluated. From the results, it was observed that the crack depth grows faster as the number of cycles increased. It was found that the initial crack of welded shell propagates slowly, and beyond 8 × 105 cycles increase quickly. In addition, the effect of stress distribution and stress intensity factor on cracking have been discussed and evaluated. The life of the component depends on the initial crack depth, stress intensity factors and crack inclination angle.
The analysis of the dimple arrangement of the artificial hip joint to the performance of lubrication
Authors: Basri Hasan , Syahrom A , Ramadhoni T S , Prakoso A T , Ammarullah M. I. , Vincent
Published: November 2019

Artificial hip joint surgery is one of the most successful methods used to restore the functioning of damaged hip bones. But there are obstacles to the use of artificial hip bone, which is the amount of friction occurring and wears. To overcome these obstacles, a surface of the artificial hip joint is modified by adding dimples in order to minimize the contact pressure of solid and to reduce friction and wear. The purpose of this study is to determine a better of lubrication performance with the variations of the dimple arrangements under the normal walking condition. Simulation results have already exited the point of convergence studies, and the obtained results are such as hydrodynamic pressure, contact pressure, and the film thickness of the lubricant with the variations of the number and pitch dimples. The results of the CSM method under dry condition, it shows that the addition of surface with dimples has a positive effect to reduce the contact pressure and indirectly reduce wear. The maximum surface contact pressure is 54.84 MPa with dimple and 94.22 MPa without a dimple. The results of the FSI method under lubrication condition, it was found that the variation of 7 dimples with a dimple pitch of 500 μm has the best lubrication performance. The hydrodynamic pressure is 0.73 Pa, the contact pressure is 0.42 Pa, and the film thickness of the lubricant is 29.59 μm. The increase of film thickness that occurs due to hydrodynamic pressure will cause the fluid lift force to withstand the loading of the solid structure.
Parting control on coal seam quality based on ash content and total moisture, North Musi Rawas, South Sumatera
Authors: Putra Jefri
Published: November 2019

In its utility, coal is measured by how much the quality values contained inside such as ash content and total moisture. One of the factors that affect the value of coal seam quality is the existence of partings. Partings is an inorganic material that is formed in coal syn-depositional. Therefore, this study aims to identify the extent influence of the presence of the parting layers that in comparison of the laboratory test results from two sampling techniques. The application of the methods used was channel sampling where the coal sample was taken without partings and include partings. Coal seam thickness become the object of the research was 9.01 m with the presence of the four partings that have a thick layer of 6-8 cm. Comparative laboratory test result show ash content include partings more bigger than without parting with a difference of 2.7% adb. Deviation ash content the most indicated on ply 5. Suggesting parting layer has form of tuffaceous sandstone. Characteristic tuff is a volcanic deposits contain a high fly ash thus increasing ash content. While the total moisture include partings more smaller than without partings with a difference of 0.3% ar, It was suggested that partings just control the ash content, this is due to the type and character of lithology parting.
Late neogen deformation of rock successions at Renah Gajah Mati I Region Seluma Regency in Bengkulu
Authors: Zuhri Wahidin , Sutriyon Edy
Published: November 2019

Studies on tectonic deformation of the Late Tertiary sequence during Late Neogene time has been carried out at the Renah Gajah Mati I region using balancing and restoring techniques, kinematic and dynamic analyses. The Late Neogene deformation was mainly controlled by compression, which has resulted in folding and thrusting. Hence, the rock sections underwent shortening that varied from 1.42-1.83 km or 0.75%-0.78% with the estimated rate of deformation 0.12-0.15 mm/year. Two types of tectonic structures developed within the region, fault propagation folds and trishear faults. The brittle deformation extended sequentially in the direction of tectonic transport, resulting in a series of faults. The generated faults constitute imbricate fans with a relatively closely-spaced thrust system. The array of thrusts is apparently associated with folds that strike NW-SE, implying the geometry of fault-linked folding. The hanging wall anticlines are generally asymmetric overturned folds, indicating a shallow ramping fault with a high shear pattern. In regional context, the general strike of structures within the study area appears relatively parallel to the NW-SE trending Barisan orogen. This feature suggests that tectonic transport was likely at the NE-SW direction.
Characteristics of quaternary volcanic rocks based on petrographic analysis in Belandang Area, Ulu Ogan, Ogan Komering Ulu
Authors: Fazri Rahmad
Published: November 2019

Administratively the research area located in Belandang, Ogan Komering Ulu District, South Sumatra Province. The astronomical located at coordinates 04, 04’ 6.9 ″-04 07’ 54.2″ LS - 103 45’ 15.1 ″- 103 49’ 1.4″ BT. The research area included in the territory of the Bukit Barisan formed on the Late Oligocene-Early Miocene and controlled by Semangko Fault Northwest-Southeast oriented accompanied by an increase in the rate of volcanic activity. Then in the Plio-Pleistocene compression and removal process occurs that causes volcanism, so that at the end of the deposition of South Sumatra Basin filled by volcanic materials. The research area is dominated by volcanic deposits consisting of, Andesite Lava, Lapilli Tuff Unit, and Agglomerates. The method used is the petrographic analysis of the 9 rock samples were considered to represent the extent of the study area, consisting of 2 samples of Andesite, 1 sample of Lapilli Tuff, and 6 samples of Agglomerate. The results are show that volcanic rocks in the study area has undergone a change that is characterized by the presence of alteration minerals such as Carbonates, Chlorite, Sericite, Quartz and Clay minerals. The presence of alteration minerals indicate that the volcanic rocks in the study area belongs to the type of alteration Phyllic and Outer/Sub Propyllitic. Based on lithological characteristics, the research area enter into the Central and Proximal Facies.
An analysis of the optimalization of bucket series against soil removal rate at The Dredger 21 Singkep 1 in PT. Timah (persero) tbk, Bangka Sea Mining Unit of Bangka Belitung Province
Authors: Handayani Harminuke Eko
Published: November 2019

Dredger 21 Singkep 1 is a ship that serves to conduct excavation of tin ore offshore. The dredger is equipped with digging tools such as bucket, ladder, ladder roll, onder roll and other supporting tools that are connected to become one unit that is called bucket series. The bucket series is the main tool of the excavation process which continuously operates that has an impact on the depreciation of the performance capability of the equipment so that it is necessary to conduct an analysis of optimization of the bucket series in order to operate optimally and the targets of the work plan of the removal rate of the soil can be achieved. Based on the observation and data analysis on the field it is known that the applied ladder suppression is 0.46 meter at the top soil and 0.26 meter at tin-borne layer which results in 229.54 m3 / hour of soil removal rate which is very far from the target of the planned work of the soil removal rate determined by the production team of 389 m3 / hour, so to fulfill the work plan of the LPT the ideal ladder suppression that must be applied is 0.57 meter for top soil and at the tin ore is 0,31 meter, out of this ideal ladder suppression, is obtained the removal rate of the soil of 408.25 m3 / hour. In addition to that, the ideal length of the steek to achieve that removal rate of the soil should be at the average maximum length of 1225 mm.
Pseudo-static slope stability analysis around the landslide at railway tunnel, South Sumatera, Indonesia
Authors: Toha M Taufik , Setiabudidaya Dedi , Ghadafi Moamar A , Adiwarman Mirza , Irvan Muhammad
Published: November 2019

On January 23rd 2016 there was a landslide in the Lahat-Lubuk Linggau railway, right at the mouth of the railway tunnel in Lahat Regency. About 5 meters thick of soil covered the railway, causing the railway to be stopped for several days. Since the tunnel was built in 1928 until landslides occur in 2016 which means it has been 88 years. The landslide can be caused by several factors, these factors are slope geometry, physical and mechanical characteristics of rocks or soil, geological structure, hydrology and hydrogeology, and external forces such as ground vibration due to railway traffic and earthquake. The results of research on the main causes of landslides in the mouth of the railway tunnel include relatively steep morphological influences, degradation of rock strength due to weathering, dip rock structure in the direction of slope, and ground vibration due to earthquakes. Based on field observations, the slope next to the case study area of the landslide is also unstable. Therefore, it is necessary to analyze the slope stability in the area that has the potential to landslide, using a pseudo-static slope stability analysis on the consideration of the effect of ground vibration due to earthquakes is quite significant to slope stability. The results of the pseudo-static slope stability analysis is showing out that the factor of safety is around 1.22-1.16 with a seismic coefficient of 0.10-0.125 g. To anticipate future landslide we suggest to be conducted studies on slope stabilization methods including building retaining walls, drainage channels and shotcrete walls.
The trial of immobilization amphoteric metals cations in clay-cement hydroisolation barierrs
Authors: Stempkowska Agata
Published: November 2019

One of the main problem of degraded post-industrial areas, preventing their introduction into the secondary economic cycle, is pollution of soil and the impact of these pollution on groundwaters. With the new European Union directives, managers are encouraged to find sound solution for these problems. The process of interaction of contaminated areas is complicated, and the transport of pollutants from the danger place to the usable underground aquifers levels passes through a series of stages of varied mileages.The article presents the possibilities of using ground binders to reduce the emission of ions from soil. The tests have shown that in the case of amphoteric metals, it is possible to accumulate almost 100% of the contamination using clay-cement suspensions.