bluuebunny/crossref_metadata_2025 huggingface dataset:
Cosmological evolution for magnetic universe based in a simple nonlinear electrodynamics
Authors: Medel-Esquivel Ricardo , Gómez-Vargas Isidro , Rivera-Moltalvo Teodoro , García Salcedo Ricardo
Published: June 2019

We investigate the cosmic dynamics of Friedmann-Robertson-Walker universes – flat spatial sections – which are driven by nonlinear electrodynamics (NLED) Lagrangian. We pay special attention to the check of the sign of the square sound speed since, whenever the latter quantity is negative, the corresponding cosmological model is classically unstable against small perturbations of the background energy density. Besides, based on causality arguments, one has to require that the mentioned small perturbations of the background should propagate at most at the local speed of light. We also look for the dynamics by mean of dynamical system tools. Our results indicate that in the case of the power law NLED Lagrangian, it is not possible to explain the current accelerated expansion stage of the universe because the model is not stable for the possible values of the free parameter that allows such expansion. Finally, in the second case, whose Lagrangian has a power law NLED term plus a Maxwell term, the model is stable and causal for a certain range of values of the free parameter.
Optical characterization of plasmas produced by concurrent application of laser and high voltage pulses
Authors: Alonso A , Sobral H , Robledo-Martinez A , Peña-Gomar M
Published: June 2019

Laser Induced Breakdown Spectroscopy (LIBS) is a simple, powerful analytic technique that is limited by a relatively low sensibility to detect traces. To improve LIBS sensitivity an option often used consists in applying a second source of excitation such as an electric discharge. This work’s goal is to investigate the interaction of a laser-produced plasma on an aluminum target with a self-triggered electric discharge. The plasma dynamics has been investigated using shadowgraphy, fast photography and the application of narrow band-pass filters to follow the evolution of the ionic and neutral species. Results show that within the initial microseconds, the spatial extent of the laser-produced plasma increases due to the presence of a low density region induced by the spark channel. Furthermore, it was found that the electric arc mainly re-excite the ionic species while the neutral ones remains unaffected.
Quantitative evaluation of the transmission spectrum in ophthalmic lenses
Authors: Gómez-Vieyra A , Talamantes-Johnson M A , Chavez-Castillo B A , Miranda-Tello J R , Vergara-Vázquez K B , Belmont-Perez F
Published: June 2019

This paper presents the analysis of the transmission spectrum in four commercial ophthalmic lenses (offered by the company “LensBest”) with different technological characteristics. To evaluate the transmission bandwidth, an experimental setup wich consists on a light source, based on an MSR700 bulb, and was implemented, which provides a UV, visible and near IR emission spectrum. A spectrophotometer was assembled with a Newport monochromator and its corresponding instrumentation. The measurement system was characterized by a sodium discharged lamp, after which a reference measurement of the light source emission was taken. Next, each of the ophthalmic lenses was placed as a sample, with the emission spectrum of the light source and the transmission spectrum of each lens, the comparison in transmission of each element was made. This work allowed us to verify the functionality of each product, as well as validate the characteristics reported by the manufacturer.
Ascending Disk: Theoretical and Numerical Study
Authors: Espíndola R , Valle G Del , Hernández G , Pineda I , Muciño D , Díaz P , Guijosa S
Published: June 2019

In this work we analyzed a classical mechanical problem: a disc with a circular hole rotating and ascending on a inclined plane. The principal idea is to show the basic equations in both Lagrangian and Newtonian formalisms and to present numerical solutions. The equations are not solvable analytically, then we proceed to integrate numerically using the standardized Runge-Kutta method of order 4. We present several phase space showing the time evolution of the system. Additionally we presented an extension of the system considering a damping factor that decays exponentially in time.
Learning Optics from the History
Authors: Repossi P
Published: June 2019

A number of studies have described the benefits of the incorporation of History and Philosophy of Science (HPS) for learning, and teaching science as a process, for promoting conceptual changes, and a deeper understanding of scientific ideas.

Physical Optics is a topic of difficult comprehension, and this fact was also observed at thePontificia Universidad Católica Argentina when students received traditional instruction. This article describes a project to improve the teaching of interference, and diffraction of light within a historical context. Care was taken in developing the line of historical thought, and the study of the hypotheses of the nature of light in proper chronological order.

In order to assess the outcome of this methodology, surveys on the subjects of interference, and diffraction of light were conductedduring three consecutive years. During the first year a textbooks based teaching without historical insight was imparted; later HPS based methods were introduced. The results show that students show more enthusiasm in lectures where the didactics uses HPS materials, and this methodology contributed to improve the students’ performance, increasing the percentage of correct answers in the exams.
Artificial vision assisted ground fine pointing system for experimental optical link for CubeSat communications
Authors: Medina I , Hernández-Gómez JJ , Miguel CR Torres-San , Couder-Castañeda C , Orozco-del-Castillo MG , Grageda-Arellano JI
Published: June 2019

Considering the continuous increase of demands in satellite communications, it is imperative to determine systems with higher bandwidths. Furthermore, miniaturization trends coming from the development of nanosatellites as CubeSat’s, constitute great restrictions to their design. Optical communications have the potential to lead with current data rates requirements. Nevertheless, the establishment of ground-LEO (Low Earth Orbit) optical links poses several challenges such as very strict and accurate tracking mechanisms, effects provoked due to the environmental conditions on the light beam as well as attenuation and Doppler effects. In this work, the precision of the tracking mechanisms is tackled by employing artificial vision as a proposal for a fine tracking system for an optical ground station to be able to locate a LEO CubeSat, so to proceed with data acquisition and tracking stages. The innovative and highly efficient algorithm herein developed for fine pointing is implemented in LabVIEW® as an example.
Clinoptilolite modified by calcium and hydroxyl ions for removal of fluoride from aqueous solution
Authors: Nuñez I Labastida , Perez M Velasco , Alvarez Dosamante K G
Published: June 2019

In Mexico naturally occurring fluoride contamination of groundwater is widespread. Adsorption with local and low-cost materials has been recently studied. In this research, clinoptilolite was modified with hydroxyl, calcium, and hydroxyl followed by calcium to compare their fluoride removal capacity. The sorption of natural and modified materials was investigated for the initial fluoride concentrations from 1.5 mg/L to 15 mg/L, isotherms for these adsorbents were investigated and techniques such as scanning electron microscopy (SEM) and X-ray diffraction (XDR) were used to characterize these adsorbents. It was found that removal fluoride was highest with calcium modified clinoptilolite from 60.2% with 1.5 mg F−/L to 43.0% with 15 mg F−/L. Sorption data for calcium modified clinoptilolite and hydroxyl and calcium modified clinoptilolite was found to fit Freundlich equations with equilibrium constants of 0.12 L/g and 0.021 L/g, respectively. SEM and XRD showed no significant changes of clinoptilolites after and before modification with calcium and sorption of fluoride, suggesting that interaction between adsorbent and adsorbate were only superficial. Modification of clinoptilolite with calcium enhanced its capacity for fluoride removal. This modification process was carried out using an economical and abundant mineral in central Mexico, which gives an additional advantage to the process.
Multifractal Analysis for the Overlapping Windows Method of a Time Series of Synthetic Earthquakes obtained with a Spring-Block Model
Authors: Aguilar-Molina A M , Perez-Oregon J , Muñoz-Diosdado A , Angulo-Brown F
Published: June 2019

We work with the model proposed by Olami, Feder and Christensen (OFC) to build time series with 10 000 000 data of synthetic earthquakes magnitudes, and conservation value β = 0.2. In this time series, we located the earthquakes with greater magnitude. We built 160 windows before and after these great earthquakes. The windows have 1024 data with an overlap of 896 points. For each windows, the values of the multifractality degree Δα and the parameter of symmetry were calculated. We follow the evolution of these parameters before and after the big earthquakes. The multifractal spectra have larger widths before than after the earthquake. The multifractal spectra of the 320 windows are left skewed, but the multifractal spectra of the time series before the earthquake are more biased towards the left than the multifractal spectra after the earthquake. Finally, we measured the curvature K around the maximum of the multifractal spectra, the K value is bigger before than after the earthquake. This suggests that there is apparently a process of preparation for the earthquake and that the dynamics after the earthquake is very different.
Characterization of thermographic images of skin cancer lesions using digital image processing
Authors: Benjumea E , Morales Y , Torres C , Vilardy J
Published: June 2019

Skin cancer is the type of cancer with the highest incidence in the world. The alterations of temperature in the skin are organic indicators of the presence of several types of skin cancer, mainly squamous cell carcinomas and melanomas. In this work, thermographic images of lesions of this type were analyzed in order to find indicators of the presence of this neoplasm that allow the future development of a detection algorithm. The digital processing used consists of identification of areas of interest, color segmentation, quantitative discrimination according to color tonality and analysis by histograms. The results showed that lesions with skin cancer have values in the red component above 100 under the RGB color space on a scale of 0 to 255. Also, when segmenting, by the k-means algorithm, a thermography containing a melanoma, the area that contains the lesion has a higher average value in the red component with respect to the other areas. Taking these results into account, a non-invasive tool for prediagnosing skin cancer can be developed that reduces unnecessary clinical procedures and simplifies the diagnosis.
Statistical study of the variable speed of an AACVD device implemented in the UTP
Authors: Hincapie J M , Castrillon E Y , Olarte W , Dorantes R J , Muñoz B Cruz
Published: June 2019

The spray assisted chemical vapor deposition (AACVD) technique is used to make thin film growth through the spraying of a precursor solution in the form of droplets, by means of a nozzle moving horizontally along the substrate. One of the most influential variables in the growth of the films is the speed with which the nozzle moves, since the deposition uniformity depends on this, which is directly related to the different physical properties of the coating. This paper briefly shows the electronic control built for the manipulation of this variable and a statistical study is presented that allowed to determine that the experimental speed presents oscillations less than 10% with respect to the programmed value. In addition, comparative transmittance spectra are shown where the reproducibility and repeatability of the coatings manufactured with the AACVD equipment built in the UTP is observed.
Multiple velocity estimation by maximum likelihood from MRI complex signals
Authors: Benitez-Read E E
Published: June 2019

The measurement of fluid velocity by encoding it in the phase of an MRI signal could allow the discrimination of the stationary spins signals from those of moving spins. This results in a wide variety of applications i.e. in medicine, in order to obtain more than angiograms, blood velocity images of veins, arteries and other vessels without having static tissue perturbing the signal of fluid in motion. This paper presents a novel theoretical and experimental method for the estimation of multiple velocities from MRI complex signals in the presence of stationary spins.
Hydrogen molecule adsorption on a Ti-doped graphene+ semi-fullerene surface.
Authors: Canales-Lizaola M , Arellano J S , Magaña L F
Published: June 2019

Density functional theory (DFT) was used to study the adsorption of a hydrogen molecule in the system formed by a graphene layer and a Ti doped semi-fullerene. We found that the semi-fullerene is bound to the graphene layer, with one of the hexagonal faces of the former being oriented into the latter, the adsorption energy is -14.97 eV. Afterwards, we found that the Ti atom is chemisorbed into the semi-fullerene, with an energy of -8.4 eV. Finally, we studied the interaction between the hydrogen molecule and the combined system, finding that the H2 is adsorbed by the system with an adsorption energy of -1.41 eV.
Arctic climate shifts drive rapid ecosystem responses across the West Greenland landscape
Authors: Saros Jasmine E , Anderson Nicholas John , Juggins Stephen , McGowan Suzanne , Yde Jacob C , Telling Jon , Bullard Joanna E , Yallop Marian L , Heathcote Adam J , Burpee Benjamin T , Fowler Rachel A , Barry Christopher D , Northington Robert M , Osburn Christopher L , Pla-Rabes Sergi , Mernild Sebastian H , Whiteford Erika J , Andrews M Grace , Kerby Jeffrey T , Post Eric
Published: June 2019

Prediction of high latitude response to climate change is hampered by poor understanding of the role of nonlinear changes in ecosystem forcing and response. While the effects of nonlinear climate change are often delayed or dampened by internal ecosystem dynamics, recent warming events in the Arctic have driven rapid environmental response, raising questions of how terrestrial and freshwater systems in this region may shift in response to abrupt climate change. We quantified environmental responses to recent abrupt climate change in West Greenland using long-term monitoring and paleoecological reconstructions. Using >40 years of weather data, we found that after 1994, mean June air temperatures shifted 2.2 °C higher and mean winter precipitation doubled from 21 to 40 mm; since 2006, mean July air temperatures shifted 1.1 °C higher. Nonlinear environmental responses occurred with or shortly after these abrupt climate shifts, including increasing ice sheet discharge, increasing dust, advancing plant phenology, and in lakes, earlier ice out and greater diversity of algal functional traits. Our analyses reveal rapid environmental responses to nonlinear climate shifts, underscoring the highly responsive nature of Arctic ecosystems to abrupt transitions.
Supply Chain Risk Management Analysis using the Development of Fuzzy Reasoning Methods and Analytical Network Process (ANP) at Wooden Toys Industries
Authors: Tanjung W N , Asti S S , Hidayat S , Ripmiatin E , Atikah S A , Khodijah R S
Published: June 2019

The supply chain is the relationship between material flows or services, money flow and information ranging from suppliers, producers, distributors, warehouses, retailers to customers. The smooth flow of material in the supply chain affected in the fulfillment of customer needs. If the problem occurs, it caused losses and risks. To minimize risks, it can be handled with Supply Chain Risk Management. This research was conducted in the supply chain in Wooden Toys Industries by identifying risks using the Fuzzy Reasoning method to calculate the amount of opportunity and impact that would arise if the risk occurred. To reduce the opportunity and impact of risk, a mitigation strategy is needed to consider and can be done using the Analytical Network Process method. Followed the results, the competitor’s moves have a large chance and risk. Thus, risk mitigation can be proposed is necessary to conduct market observations and identify competitors at (31.3%).
Measuring Influence from Safety Climate to Safety Behavior in Bus Rapid Transit Drivers
Authors: Safitri D M , Mediana A , Septiani W
Published: June 2019

Safety climate and safety behavior has an essential contribution to safety in all forms of the organizations. This research aimed to measure the impact of safety climate on safety behavior on bus rapid transit drivers in Jakarta. Bus rapid transit accident occurred inside and outside the bus lane. The incidence of the accident indicates that the risk is real. The measurement of the safety climate was using Nordic Safety Climate Questionnaire (NOSACQ-50). The NOSACQ-50 was adapted to fit the characteristics of transportation object. The questionnaire was distributed to 100 bus rapid transit drivers in Jakarta. Structural Equation Modelling – Partial Least Square (SEM-PLS) method was used to determine the influence safety climate to safety behavior among bus rapid transit drivers. The testing on the outer and inner model was conducted by bootstrapping and blindfolding process using Smart PLS software on the significance level of 0.05. The results of the study are that the workers’ safety commitment and safety communication, learning, and trust in co-workers’ safety competence had a positive and significant influence on safety behavior.
Workplace Ergonomic Risk Assessment Toward Small-Scale Household Business
Authors: Mufti Dessi , Ikhsan Aidil , Putri Tri Marta
Published: June 2019

The purpose of this research is to assess work risk caused by non-ergonomic of both facility layout and workplace at some Small Scale Medium Enterprises (SMEs) at nagari Batu Taba, sub-district IV Angkek, West Sumatera. The research samples are traditional food industrial and convection. The research participants are those who have been worked for more than ten years. Amongst the grievances experienced by the worker are tiredness and musculoskeletal disorders. This evaluation adopts the ergonomic facility layout and workplace through using Workplace Ergonomic Risk Assessment (WERA). The assessment result by implementing WERA shows that the worker does experience risk with final score 30 at medium level, as for the worker who cut the clothes pattern is at high level, 45. Task is not accepted and immediately changes. It means that some recommendations to improve the workplace are of vital importance. The ergonomic design introduced in this research has potential to reduce the risk at some small scale industrial at nagari Batu Taba, sub-district IV Angkek.
Analysis of Machine Maintenance Processes by using FMEA Method in the Sugar Industry
Authors: Soewardi Hartomo , Wulandari Siska Ari
Published: June 2019

Sugar is the daily basic need of human life. It is made from cane trees and manufactured using a milling machine in the early stages. This machine is operated 24 hours per day; consequently, it should be in a good condition and the company must be able to ensure the machine can run well by scheduling regular maintenance. This study aimed to investigate the potential failure of manufacturing process to provide some recommendations for improvement. Failure Mode and Effect Analysis (FMEA) method was applied to analyze the situation, and Logic Tree Analysis (LTA) was implemented to classify the types of improvement. This study found 13 failure modes, including a loose hammer tip, a broken end of the cutter, a non-balanced hammer rotation, a broken hammer handlebar, a broken wheel bearing, a loose switch, a loose split pen, a loose fastener bolt, an overload, a destroyed rubber seal, a broken turbine coupling, a broken screw-bolt, and a hollow roller. Meanwhile, the classification of improvement consisted of 3 categories namely safety problem (A), outage problem (B), and economic problem (C). Subsequently, the A category recommended setting up the machine in accordance with SOP while the B category recommended inspecting the machine routinely and preparing parts. In addition, the C category recommended performing accurate installation, lubrication, and cleaning.
The Optimization of Semi Finished Garment Distribution of Forboys SME in Pandeglang Area Using Genetic Algorithm
Authors: Tanjung WN , Nurhasanah N , Lutfia CF , Aribowo B , Safitri R , Samiono B , Devana M , Kalifa P , Fauzia SW , Supriyanto A
Published: June 2019

Distribution is one of crucial activities for a company because it will benefit the company from the sales of its distributed products. One way to facilitate distribution is determining an optimal route. Determining an optimal route is an important issue to solve since it can affect vehicle operating cost and time. Moreover, it is required to obtain an efficient route. This research deals with the optimization of distribution route of a garment SME located in Pandeglang, namely Forboys (FBS), who produces children’s clothing. This research attempts to seek which route is best for distributing semi-finished goods from FBS Warehouse to each CMT in Pandeglang, so as to minimize the cost incurred. In order to distribute semi-finished goods quickly, an efficient distribution route from FBS Warehouse to each CMT is required. This research is conducted uses Genetic Algorithm method. Genetic algorithm which is reliable in producing optimal output that can be used to solve the most appropriate for this type of problem. Based on the results of the research, the optimum route is found to be the one starting the delivery from FBS Warehouse - CMT 3 - CMT 2 - CMT 1 and back to FBS Warehouse, with a total distance of 205.5 km and the cost incurred for each distribution of IDR 386,500.
Utilizing project management software in project scheduling: a case study
Authors: Miranda Suci , Sugarindra M
Published: June 2019

Project scheduling is the application of skills, techniques, and intuition acquired through knowledge and experience to develop effective schedule models. It is integrated with various project components, such as activities, resources, and logical relationships. This is a case study of project scheduling under resource-constrained in an aircraft industry. In order to successfully run a project should focus on the project accomplishing effort related to the deadline. When the schedule execution of activities does not meet the project scheduling plan, the entire project may take longer duration to achieve the deliverables. This paper presents a rearranged schedule compared to the current set. Utilizing project management software (PMS), the project can be finished in 91 days employing 12 operators. Microsoft Project is preferred for further evaluating and managing project scheduling solution. The data is treated automated and the leveling method is applied to compress the completion project time related to the scope of the study is the limited resources allocated. Leads and lags have been identified regarding the new schedule results. The project can be accomplished quickly enough using the rearranged schedule.
Planting System Modeling Of Chrysanthemum Seedling Plants Stock for Profit Optimization
Authors: Ilmaniati A , Taufik D H
Published: June 2019

Inventories of conventional agricultural cultivation products are closely related to available land area. Often the area of available land is not comparable to meet all demands and cause a profit loss. Appropriate planting management is needed to minimize the profit loss. This study aims to optimize the profit from Chrysanthemum seedling cultivation on Cianjur seedling plantation by developing a model of decision-making system through simulating the planting proportion between varieties. The method used in this research is by using hard method operational research (OR) approaches, while the simulation process is done using spread sheet excel with manual input. The results showed that in one planting period required four times planting with the particular planting proportion. The total profit generated from the best scenario simulation is IDR. 385,779,274.19 with 24.63% profit from first planting, 26.26% from second planting, 27.97% from third planting and 21.13% from fourth planting. The results of this study provide a basis for determining the decision of planting patterns compared with existing conditions that have not used the planning model at all.
Optimum Container Network Route in Papua Region
Authors: Natalia Christine , Oktavia Chendrasari Wahyu , Eirene Gabriela
Published: June 2019

Indonesia is an archipelagic country which around 77% of its area is covered by water. Thus, developing good logistic system is needed especially in water-based route to distribute goods to the entire country. To develop national logistic system, government establishes Sea Highyway concept. This new concept is expected to lower the logistic cost for Eastern side of Indonesia especially Papua. The existing routing system has not yet established to reach all the seaport at Papua. This issue will still force air-based and land-based distribution system to take over most of its distribution activity. The main discussion of this research is to determine the most optimal routing system for container shipment in Papua. The determination of optimal routing system applies Integer Linear Programming for its approach. The scope of this research would be the container shipment originated from Tanjung Perak and Makassar. The seaports taken into account for this research consist of 3 hub ports and 7 feeder ports. Based on the calculation, 54 alternatives routing are determined and 22 of these are the most optimal routing system for container shipment in Papua.
Forecasting Methods and Implementation of DRP (Distribution Requirement Planning) Methods in Determining the Master Production Schedule
Authors: Magdalena Riana , Suli Theresia
Published: June 2019

PT ABC President Indonesia is a manufacturing company engaged in the food sector by producing ABC noodles and Nu Greentea. At PT ABC President Indonesia, the production scheduling process is one of the main processes carried out to determine the number of products that must be produced. Based on the problems that occur regarding stock, it is proposed that the best forecasting method is based on the time series of each Distribution Centre (DC) and processing Distribution Centre (DC) requests using the Distribution Requirement Planning (DRP) method. Where the DRP method is used, so that the company can meet the demand of every DC so that there is no shortage of products and the production process continues to run without the company experiencing losses. In addition, with the use of DRP method there will be additional stock so that if there is a defect, the company still has stock remaining so that it can still meet the customer demands for each DC and the product distribution process runs more regularly.
Applying value stream mapping tools and kanban system for waste identification and reduction (case study: a basic chemical company)
Authors: Kosasih Wilson , Sriwana I K , Sari E C , Doaly C O
Published: June 2019

This paper describes how to apply both of value stream mapping tools and kanban system for identifying and reducing wastes that happened on shop-floor. This research was conducted at a basic chemical company which produces the thinner. This study aims to reduce even to eliminate the types of waste that occur on the production line of jerrycan product type. The plot of VSM is used to picture the entire of value stream. The value stream mapping tools are used to analyze the certain waste after it has been figured out by using waste assessment model. Hence in this study two selected tools were applied and discussed further, i.e. process activity mapping, and supply chain response matrix. The Current-VSM shown that value-added time of 472.33 s compared with total lead time of 132,568.76 s, consequently obtained process cycle efficiency (PCE) approximately 0.36%. Kanban system will be implemented to eliminate waste of unnecessary inventory throughout the value stream. At last, the result of improvements shown that value of PCE probably will increase by 67.25%, non-value activity will reduce 6.74%, as well as order fulfillment time of the whole process will be 13 days with 3.59 days of physical stock.
Waste assessment using lean manufacturing in rubber production
Authors: Amrina Elita , Putri Nilda Tri , Anjani Dwara Mitha
Published: June 2019

During the rubber production process, there are several wastes caused by breakdown machines, damaged equipments, and production delays. Those wastes have negative impact to companies and thus, need to be eliminated. This study aims to assess wastes in rubber production process using lean manufacturing approach. Waste Relationship Matrix (WRM), Waste Assessment Questionnaire (WAQ), and Value Stream Analysis Tools (VALSAT) are applied to identify the wastes. Fishbone Diagram is then used to determine the root cause of problems. Finally, Failure Mode and Effect Analysis (FMEA) method is applied to evaluate the source of wastes and develop the action plans. It indicated that over production, inventory, and defects as the three highest wastes in the rubber production. Process Activity Mapping (PAM) is selected as the analysis tools in VALSAT and it obtained the activities in the rubber production are mostly categorized into value added activities. The necessary but non value added activities are also identified at a fairly high frequent. The major risks during the rubber production is related to dynamo damage and machine clogged in both hammer mill and mangle machine. It needs high attention from the production manager of rubber industry. Then, action plans are suggested to improve the maintenance program.
Maintenance management improvement based on reliability centered maintenance II in energy generating industries
Authors: Singgih M L , Prasetyawan Y , Sutikno  , Hartanto D , Kurniawan F R , Wicaksana W T
Published: June 2019

The X power plant is one of an electric company subsidiaries. Engaged in providing electricity for the certain regions. In general, the type of treatment from X power plant is short and long term maintenance. The application of these two systems helps X power plant to maintain the machines. The author argues that the type of maintenance from X power plant is not or is not yet optimal, the author wants to test whether reliability centered maintenance II treatment method can be applied in X power plant so that the efficiency and maintenance of the machine is in accordance with their individual needs. After implementing the RCM II information worksheet and RCM II decision worksheet, it is found that the existing maintenance management system in X power plant can be. Several incompatibility are detected, and should be matched with the corresponding maintenance method. For further research, the author recommend that the object of research are broadened so that the RCM II method can be used on other energy generating industries.
Redesign of office layout using activity relationship chart (ARC) at the “X” department administration office of a “Y” university
Authors: Wahyukaton  , Affifah Ghina
Published: June 2019

Administration office at “X” Department is a room for managing papers and letters administration, documentation, archiving, and also a room for communication to lecturers and students and office administrators. This room needs to have good layout in order to support the activity for all elements within the department. Redesign the office layout will reduce the time to wait for completing the letters which are needed by the students and the lecturers. This paper’s objectives are to improve the information flow and data flow, to reduce the documents stack, and to create a comfortable office to meet the facility layout principles. Activity Relation Chart (ARC) is been used to redesign the office layout by distributing questionnaires to the students and officers and lecturers to obtain the preference of closeness to construct the chart. The result is to redesign the desk into “L” shape to reduce the movements. Also, this result was explained later by a simulation using ARENA.
Integration of Lean Manufacturing and Group Technology Layout to increase production speed in the Manufacture of Furniture
Authors: Tarigan U , Tarigan U P P , Sukirman V
Published: June 2019

PT. ABC is a wood processing company which manufacture household appliances such as chair, table, wagon, shelf, and clothen hanger using rubber wood as the base material. Based on the results of observations made on the company, it was known that the production process in the company still having many non-value added activities such as delay and long distance transportation activities, causing longer lead time of the production process. From the problems that exist in the company, lean manufacturing approach is used to reduce non value added activities by using Value Stream Mapping to identify activities which are value added and which are the non-value added then to reduce non-value added activities 5W and 1H principles is used. After non-value added activities have been reduced, followed by Group Technology Layout approach to design three alternative layouts with the purpose of minimize the distance between station. This study aims to eliminate non-value added activities through simplification of the production process and redesign of the layout to reduce production time. The results of this study concluded that using this method the manufacturing lead time is decreased from the beginning of 19237.4 seconds to 14340.3 seconds. In addition, process cycle efficiency also increased by 34.15% and the completion of the process also increased by 20 units or by 25.64%.
Implementation of Material Requirement Planning (MRP) on Raw Material Order Planning System for Garment Industry
Authors: Hasanati Nidaul , Permatasari Effrizka , Nurhasanah Nunung , Hidayat Syarif
Published: June 2019

The increasingly competitive business environment has encouraged many actors to use information and communication technology as a competitive advantage, including the garment industry. So far, difficulties in controlling raw material inventories which causes problems for the production process. If there is a shortage of raw materials, the production process cannot be carried out, on the contrary if the raw material ordered is too excessive it will cause excess and the high cost of raw material inventory. This research develops an information system that can plan the needs of raw materials needed for production. This system is web-based, applying the MRP (Material Requirement Planning) method to develop raw material ordering planning systems, case studies at garment companies, using PHP programming and FIREBIRD databases. This system gets input from the production schedule resulting from production scheduling information system, then provides output in the form of recommendations for scheduling raw material orders. This output can later be used as a reference for the company’s operational decisions in planning raw material requirements.
Simulation Model Development for Determination of Components Production Quantity and Lead Time Reduction in Mass Customisation of Single Production Stage
Authors: Purnomo M R A , Shinta R C
Published: June 2019

Market rivalry forces manufacturing companies to be customer focus and have an agile system. In manufacturing companies that produce semi-common products based on customer order, the pressure from customers are usually faster delivery, reasonable price and higher product variability. This paper presents the use of Mass Customisation (MC) concept in order to cope with faster delivery and higher product variability. The MC concept is realised by determining Customer Order Decoupling Point (CODP). Besides MC, Theory of Constraint (TOC) concept is also applied in order to address problem that may occurred after MC implementation. Based on a simulation analysis, it shows that CODP implementation could improve delivery lead time and product variability performance dramatically up to 5.15 times compared to existing system. An optimisation algorithm is also proposed for further study in order to improve cost performance of the products.
Kinetics of Fly Ash Geopolymerization using Semi Quantitative Fourier-Transform Infrared Spectroscopy (FTIR); Corr Data
Authors: Murti Petrus Himawan Tri Bayu , Adelizar Arie Satya , Widiyatmoko Achmad , Olvianas Muhammad , Suprapta Wisnu , Perdana Indra , Prasetya Agus , Astuti Widi
Published: June 2019

Fly ash utilization is very urgent to be conducted alas contaminating the environment. One of the promising utilizations is geopolymer formation for material construction. In this study, geopolymer formation was studied using fly ash from PLTU Tanjung Jati Jepara. This study included kinetics prediction using solid state isoconversion kinetics that has been developed based on nucleation, geometric contraction, and diffusion models. Semi quantitative FTIR analysis (corr) has been applied to predict the kinetics of the fly ash geopolymerization in curing temperature of 30о and 90°C. In order to be able to verify the kinetics model time series data were taken in interval of 1,3,5,14,21, and 28 days. It is the diffusion model that represents the fly ash geopolymerization with R2 of 0.9437.
Design and Mechanism Analysis of Paddlewheel Aerator with Movable Blades
Authors: Bahri Samsul , Agus Setiawan Radite Praeko , Hermawan Wawan , Junior Muhammad Zairin
Published: June 2019

The successful of intensive aquaculture is strongly influenced by the ability of the farmers to overcome the deterioration of water quality. The problem is low dissolved oxygen through aeration process. The aerator device which widely used in pond farming is paddle wheel aerator because it is the best aerator in aeration mechanism and usable driven power. However, this aerator still has a low performance of aeration, so that the cost of aerator operational for aquaculture is still high. Up to now, the effort to improve the performance of aeration was done by two-dimensional blade design. Obviously, it does not provide an optimum result due to the power requirements for aeration is directly proportional to the increase of aeration rate. The development of movable blade is based on fact that power is required only when blade of paddle wheel aerator entering water and in contrary action of aeration effect only when the blade is about leaving the water. This study was carrier out to design paddle wheel aerator with movable blade which will open when entering water and close when leaving water. Wheel closed at quadrant I to IV (entering water surface) and was about to open at quadrant III to II (leaving water surface). The blade was designed referring to commonly used Taiwan wheel model. The size of the blade was 15 cm of width, 20 cm of length, trapezoid-shape with 15˚ of bottom side and 30˚ of top side, had 40 holes with diameter of 1.6 cm. The component of mobable blade mechanism consisted of cam and shaft, rim, rim cap, blade holder, follower, spring and bearing. Follower was able rotate with angle of rotation was 1250, rotational displacement was 50 mm, maximum velocity was 0.55 m/s and acceleration was 6.09 m/s2. The largest angle of pressure occurred between cam and follower was 40.120 and the maximum torque required to rotate movable wheel was 80.09 Nm. The result shows that the testing without a load at 115 rpm, the torque that occured is 43.05 N·m and the electric power consumption is 511.72 Watt. However, the electrical consumption is still higher comparing with Taiwan paddlewheel aerator model due to the friction occured on the follower and cam.
The effect of time and number of balls on shaker milling process in hydroxyapatite powder synthesis
Authors: Fadli A , Yenti S R , Rasyidin R , Sari M
Published: June 2019

The synthesis of hydroxyapatite (HA) from the shells of blood clams has been successfully performed by the low temperature hydrothermal method. To obtain uniform and nano-HA powder, size of obtained HA was reduced using shaker milling process. The purpose of this research was to determine the effect of time and the number of balls on the shaker mill process on hydroxyapatite particle size. The shells of blood clams were calcined at 1000 °C for 24 hours to obtain CaO powder. Then 55.63 gram (NH4)2HPO4 dissolved in 600 mL of distilled water then added 45,91 gram of CaO at 90 °C to form slurry. The slurry was dried at 120 °C for 15 hours, and milled using shaker milling process with variation of time 1, 2 and 4 hours and variation of number 10, 20, and 30 balls. The peak intensities show the high percentage of HA with Tricalcium phosphate (TCP) presence in X-ray diffraction (XRD) analysis. Diameter of crystal produced is 67 nm, with time variation for 2 hours and number of 20 balls. Breuner-Emmet-Teller (BET) analysis result, with time ball milling for 1 hour and the number of 10 balls surface area of HA is 36,974 m2/g. The longer of milling process, the temperature will also increase causing clumps of particles resulting in an increase in particle size. The more the ball is used then the surface area of obtained hydroxyapatite will be smaller.
Extraction of ElectroEncephaloGraph (EEG) Signal Using the Subband Coefficient of Wavelet Transform on Cursor Moves
Authors: Hindarto H , Muntasa A
Published: June 2019

This research explains the application of ElectroEncephaloGraph (EEG) signal waves used to move the up cursor and down cursor. In each sub band of the waveform, Electro Encephalo Graph (EEG) will produce the average and standard deviation to be used as a feature of the EEG. Artificial Neural Network Backpropagation as the basis for determining whether the cursor moves up or the cursor moves down. The data used in this study is EEG data derived from BCI Competition 2003 (BCI Competition 2003). Decision-making is done in two stages. In the first stage, the mean and standard deviation values on each wavelet subband as a feature extraction of EEG data. This feature is an input to the Backpropagation Neural Network. In the second stage of the process of inserting into two classes (class 0 and class 1) EEG data files, there are 260 EEG and 293 file training data files from EEG file test data files, totaling to 553 EEG data files. The results obtained for the classification of EEG results were 79.2%.
Functional cake characteristics of modified arrowroot starch (MAS) with the gelatinization-retrograde method
Authors: Damat D , Tain A , Handjani H , Chasanah U , Siskawardani D D
Published: June 2019

Healthy food consumption is a critical issue which enhances the functional food production demand. This research aimed to identify the optimum modified arrowroot starch for the best functional cake characteristics. Completely Randomized Design with one factor (arrowroot starch: wheat flour proportion) which consisted five levels (0:100; 25:75; 50:50; 75:25 and 100:0) was applied. The first step was MAS production (gelatinization-retrograde method) then applied to functional cake followed by proximate, resistant starch, expansion volume index and texture analysis. The result showed that 100% MAS was the best treatment with the highest carbohydrate and resistant starch (25.85% and 59.28%), and the lowest ash content, hardness, and expansion volume index (1.8%, 104.95N/mm2 and 45.32%). It can be concluded that functional cake characteristic becomes better and resistant starch (RS) level become higher with MAS application.
Integration Distance Similarity with Keyword Algorithm for Improving Cohesion between Sentences in Text Summarization
Authors: Darmawan Rizki , Wijaya Adi
Published: June 2019

In recent time the exponential growth of textual information available on the Web, end user need to be able to access information in summary form. Commonly the method to get the summary is extraction method. One of extraction method that easier and commonly used is Keyword Algorithm, but this algorithm has a weakness in the cohesion between the sentences. Distance similarity method is one method used for solving the cohesion problem. The idea of this paper is to improve cohesion between sentences based on extraction of keyword algorithm. The hybrid keyword algorithm and the distance similarity method is proposed. The proposed method was compared three distance similarity such as Cosine, Dice and Jaccard that looking for the cohesiveness between sentences according to keyword algorithm extraction and performance as standard of evaluation. The result showed that Dice has the highest cohesion degree is 45.87 %. Although the best performance is Cosine that performance is influenced with gold standard of abstractive human summary.
Developing organic feed stuff as the main component of broiler chickens’ feed with canvas model in East Java: A Case Study of Analysis on Organic Rice and Corn in Malang and Tulungagung
Authors: Sutanto A , Widodo W , Rahayu I D
Published: June 2019

In general, this research aimed to: [1] analyze the market profile and supporting institution regarding the obtainability of productions and demands; [2] investigate the agri-business institution and organization on empowering the organic feed availability especially for the broiler chickens.This research belonged to surveying research through accommodating surveys respectively piloted in Malang and Tulungagung. Therefore, the method for this research referred to survey recruiting 62 respondents in total that was assisted by interview to the main informants, group discussion, and document analysis (converted as secondary data). Moreover, for analyzing the data, the descriptively qualitative and interpretative design was accommodated by means of Business Canvas Model (BCM) approach. By and large, the conclusions of this research were formulated as follows: [1] in accordance with the market profile and supporting institution regarding the availability of productions and demands, the market reinforcement was of necessity in order to advance the productions’ values as well as the farmers’ incomes in supplying the organic feed; and [2] regarding the agri-business institution and organization on providing the broiler chickens with organic feed, the highly serious exertion from all of elements, exclusively all the stakeholders, was of compulsory in addition to empower the progress and success of organic farming. In addition, the management of farmers’ institutions centralizing on production was required to be maintained. Therefore, the collaboration of various farmers’ institutions was of urgency to be reinforced.
Chemistry and Structure Characterization of Bamboo Pulp with Formacell Pulping
Authors: Hidayati S , Suroso E , Satyajaya W , Iryani D A
Published: June 2019

Bamboo is one of the non-wood materials which can be utilized as raw materials of pulp. The purpose of this work was to study the effect of the ratio of acetic acid:formic acid on the chemical properties of pulp from bamboo. The results of the study showed that increases of the ratio of formic acid able to degraded of cellulose, hemicellulose, lignin content and decreases the pulp yield. The best condition of this research showed on the ratio of acetic acid: formic acid = 90:10. This condition produced the pulp with composition consist are cellulose 66,98%, hemicelluloses 16,83%, and lignin 3,59%, with the yield of pulp is 42,279%