Aditia Rifai - Academia.edu (original) (raw)
Papers by Aditia Rifai
2018 International Conference on ICT for Rural Development (IC-ICTRuDev), 2018
In general, the communications equipment that used for the oil palm plantations area in Indonesia... more In general, the communications equipment that used for the oil palm plantations area in Indonesia is still employing a handy-talky device or SSB radio. In some densely populated areas, the communications are using cell phones that connected to the telecommunication operators' networks. Nevertheless, most of the oil palm plantation in Indonesia is located in rural and remote areas which lack of network services. With OWNGrid product, we expect that it can be used as a long-range communication device alternative for oil palm plantations. OWNGrid uses LoRa technology as base and smartphone with specific android apps for chatting service. Hopefully, it can help in improving the efficiency and effectiveness during oil palm harvest.
JURNAL INFOTEL, 2018
In this paper, development progress of a long-range radio communication-based fishing assistant s... more In this paper, development progress of a long-range radio communication-based fishing assistant system called e-Nelayan is reported. The purpose of the system is to increase the productivity, safety, and welfare of fishermen using mobile phone and long-range radio based system that enables them to report maritime violations, access and exchange information regarding weather, fishing area, and marketplace, as well as communicate with mainland using Android-based mobile phone within extended range. We used LoRaWAN as a base technology for long-range communication scheme. In this work, the test conducted to obtain an insight to e-Nelayan device (LoRa-based) received RSSI and its packet loss. The received data collected in a server also includes the GPS tracking data. The test results show that our system can reach about 5 km of distance between end-node to the LoRa Gateway within urban area (LoS configuration) and about 2 km for NLOS configuration.
Progress in Organic Coatings, 2019
A sol-gel coating using colloidal silica on a glass surface is carried out towards improving the ... more A sol-gel coating using colloidal silica on a glass surface is carried out towards improving the self-cleaning properties. The optical transmittance and hydrophobic characteristics of the resulting coating are analyzed using analytical tools. Since the sol-gel coating reduces the optical transmittance of the glass samples, due to scattering and diffusion of the incident optical radiation at the coating surface, silicon oil (Sigma-Aldrich, 10 cSt) impregnation method is introduced to improve the optical transmittance. Silicon oil has good heat transfer characteristics, stable properties over range of temperatures, and optically transparent characteristics with refractive index of 1.4034. The resulting coated surface is tested in outdoor environments to examine the dust effect on the optical transmittance of the sol-gel coated and oil impregnated glass samples. It is found that deposition of 75 nm size silica particles on the glass surface modifies the texture height of the sol-gel coating, which in turn, improves the surface hydrophobicity. Sol-gel coating results in a web-type fully connected porous structures; in which case, agglomeration of the synthesized particles is responsible for the fully connected porous texture at the coating surface. The optical transmittance remains low for the sol-gel coated glass samples because of scattering and diffusion of the incident optical radiation at the coating surface. Silicon oil impregnation improves the optical transmittance of the sol-gel coated samples. The dust particles immerse into the oil film and reduce the optical transmittance of the oil impregnated samples in outdoor environments.
Solar Energy Materials and Solar Cells, 2017
Maintaining the high performance of photovoltaic devices requires regular cleaning of panel surfa... more Maintaining the high performance of photovoltaic devices requires regular cleaning of panel surfaces because of the environmental dust settlements in harsh weather conditions. Self-cleaning characteristics of such surfaces are vital for the cost effective operations. In the present study, a new fabrication approach is introduced towards selfcleaning applications of optically transparent glasses. In the fabrication process, self-assembly monolayer of silane was coated on the silica nanoparticle layer, prior to oil impregnation, to improve oil hydrodynamic stability of the oil film on the surface. The static water contact angle, sliding angle and average optical transmittance of the resulting surfaces are measured. The scanning electron microscope and atomic force microscope are used to reveal the hierarchical morphology of the surface. Dust cleaning tests are performed to evaluate the self-cleaning characteristics of the surfaces. The findings revealed that the water droplets can be effectively used to remove almost all of the dust particles from the surfaces. Oil impregnation improved the optical transmittance of the treated hydrophobic glass surface.
Solar Energy, 2016
Abstract The dynamic response of the dust particles on the rotating polycarbonate disk is examine... more Abstract The dynamic response of the dust particles on the rotating polycarbonate disk is examined in relation to the cleaning of the photovoltaic protective cover. Forces developed on the dust particles due to the rotational motion of the disk are formulated and predicted in line with the experimental conditions. The comparison of the resulting forces including centrifugal, gravitational, drag, lift, adhesion, and friction forces is carried out for various locations on the disk, different rotational speeds and several dust particle sizes. The dust particles collected from the local environment are analyzed using the analytical tools including scanning electron and atomic force microscopes, energy dispersive spectroscopy, and X-ray diffraction. An experiment is carried out to assess the dust removal from the polycarbonate disk surface. The dust residues after the tests are analyzed and adhesion force between the dust particles and the polycarbonate surface is measured. It is found that centrifugal force remains higher than the adhesion, friction, drag, lift, and gravitational forces in the region away from the rotational center. The dust particle size and rotational speed significantly influence the rate of dust removal from the disk surface.
AIP Conference Proceedings, 2011
ABSTRACT SnO2 thin films were deposited on glass substrate by chemical bath deposition (CBD) with... more ABSTRACT SnO2 thin films were deposited on glass substrate by chemical bath deposition (CBD) with stannous chloride (SnCl2..2H2O) as a precursor and urea (CO(NH2)2) as a buffer. X-Ray Diffraction (XRD) are used to characterize the structure of the films; the surface morphology of the films were observed by Scanning Electron Microscope (SEM). Using this techniques, we specify the effect of stannous chloride concentration and weight ratio of urea/H2O on the crystallinity and morphology of these films. The rutile structure corresponding (110), (101) and (211) planes of SnO2 is obtained. The increasing of stannous chloride concentration and the decreasing weight ratio of urea/H2O is found to improve the crystallinity of the film. The average diameter of grain size is about 96 nm.
2018 International Conference on ICT for Rural Development (IC-ICTRuDev), 2018
In this paper, we report the initial study to design and development of long-range wireless commu... more In this paper, we report the initial study to design and development of long-range wireless communication system based on LoRa technology for Indonesian fishermen in which the targeted ship is under <5 GT (small-ship category). The developed system consists of 1) customizable end-node; 2) Android apps equipped in a smartphone as a user interface (namely e-Nelayan app); 3) gateway; 4) and a server application for online monitoring purpose. The e-Nelayan app covers three features: the SOS button, chat, and recent weather information. While the end-node part includes Bluetooth module, Microcontroller, Long-range radio module, power regulator circuit, and Li-Po battery for main supply, all of them are packed based on the consumer product. The discussion of this paper focuses on a) the brief description of the proposed system; b) the profile of developed android app, c) and anatomy of the hardware. Moreover, the tests (both for laboratory test and field test) also have been observed. Since the proposed system is an initial study, hence we conduct on the demo of ‘ping connection’ in lab scale test. While for the field test, we used RSSI analysis and object tracker test.
2018 International Conference on ICT for Rural Development (IC-ICTRuDev), 2018
In general, the communications equipment that used for the oil palm plantations area in Indonesia... more In general, the communications equipment that used for the oil palm plantations area in Indonesia is still employing a handy-talky device or SSB radio. In some densely populated areas, the communications are using cell phones that connected to the telecommunication operators' networks. Nevertheless, most of the oil palm plantation in Indonesia is located in rural and remote areas which lack of network services. With OWNGrid product, we expect that it can be used as a long-range communication device alternative for oil palm plantations. OWNGrid uses LoRa technology as base and smartphone with specific android apps for chatting service. Hopefully, it can help in improving the efficiency and effectiveness during oil palm harvest.
JURNAL INFOTEL, 2018
In this paper, development progress of a long-range radio communication-based fishing assistant s... more In this paper, development progress of a long-range radio communication-based fishing assistant system called e-Nelayan is reported. The purpose of the system is to increase the productivity, safety, and welfare of fishermen using mobile phone and long-range radio based system that enables them to report maritime violations, access and exchange information regarding weather, fishing area, and marketplace, as well as communicate with mainland using Android-based mobile phone within extended range. We used LoRaWAN as a base technology for long-range communication scheme. In this work, the test conducted to obtain an insight to e-Nelayan device (LoRa-based) received RSSI and its packet loss. The received data collected in a server also includes the GPS tracking data. The test results show that our system can reach about 5 km of distance between end-node to the LoRa Gateway within urban area (LoS configuration) and about 2 km for NLOS configuration.
Progress in Organic Coatings, 2019
A sol-gel coating using colloidal silica on a glass surface is carried out towards improving the ... more A sol-gel coating using colloidal silica on a glass surface is carried out towards improving the self-cleaning properties. The optical transmittance and hydrophobic characteristics of the resulting coating are analyzed using analytical tools. Since the sol-gel coating reduces the optical transmittance of the glass samples, due to scattering and diffusion of the incident optical radiation at the coating surface, silicon oil (Sigma-Aldrich, 10 cSt) impregnation method is introduced to improve the optical transmittance. Silicon oil has good heat transfer characteristics, stable properties over range of temperatures, and optically transparent characteristics with refractive index of 1.4034. The resulting coated surface is tested in outdoor environments to examine the dust effect on the optical transmittance of the sol-gel coated and oil impregnated glass samples. It is found that deposition of 75 nm size silica particles on the glass surface modifies the texture height of the sol-gel coating, which in turn, improves the surface hydrophobicity. Sol-gel coating results in a web-type fully connected porous structures; in which case, agglomeration of the synthesized particles is responsible for the fully connected porous texture at the coating surface. The optical transmittance remains low for the sol-gel coated glass samples because of scattering and diffusion of the incident optical radiation at the coating surface. Silicon oil impregnation improves the optical transmittance of the sol-gel coated samples. The dust particles immerse into the oil film and reduce the optical transmittance of the oil impregnated samples in outdoor environments.
Solar Energy Materials and Solar Cells, 2017
Maintaining the high performance of photovoltaic devices requires regular cleaning of panel surfa... more Maintaining the high performance of photovoltaic devices requires regular cleaning of panel surfaces because of the environmental dust settlements in harsh weather conditions. Self-cleaning characteristics of such surfaces are vital for the cost effective operations. In the present study, a new fabrication approach is introduced towards selfcleaning applications of optically transparent glasses. In the fabrication process, self-assembly monolayer of silane was coated on the silica nanoparticle layer, prior to oil impregnation, to improve oil hydrodynamic stability of the oil film on the surface. The static water contact angle, sliding angle and average optical transmittance of the resulting surfaces are measured. The scanning electron microscope and atomic force microscope are used to reveal the hierarchical morphology of the surface. Dust cleaning tests are performed to evaluate the self-cleaning characteristics of the surfaces. The findings revealed that the water droplets can be effectively used to remove almost all of the dust particles from the surfaces. Oil impregnation improved the optical transmittance of the treated hydrophobic glass surface.
Solar Energy, 2016
Abstract The dynamic response of the dust particles on the rotating polycarbonate disk is examine... more Abstract The dynamic response of the dust particles on the rotating polycarbonate disk is examined in relation to the cleaning of the photovoltaic protective cover. Forces developed on the dust particles due to the rotational motion of the disk are formulated and predicted in line with the experimental conditions. The comparison of the resulting forces including centrifugal, gravitational, drag, lift, adhesion, and friction forces is carried out for various locations on the disk, different rotational speeds and several dust particle sizes. The dust particles collected from the local environment are analyzed using the analytical tools including scanning electron and atomic force microscopes, energy dispersive spectroscopy, and X-ray diffraction. An experiment is carried out to assess the dust removal from the polycarbonate disk surface. The dust residues after the tests are analyzed and adhesion force between the dust particles and the polycarbonate surface is measured. It is found that centrifugal force remains higher than the adhesion, friction, drag, lift, and gravitational forces in the region away from the rotational center. The dust particle size and rotational speed significantly influence the rate of dust removal from the disk surface.
AIP Conference Proceedings, 2011
ABSTRACT SnO2 thin films were deposited on glass substrate by chemical bath deposition (CBD) with... more ABSTRACT SnO2 thin films were deposited on glass substrate by chemical bath deposition (CBD) with stannous chloride (SnCl2..2H2O) as a precursor and urea (CO(NH2)2) as a buffer. X-Ray Diffraction (XRD) are used to characterize the structure of the films; the surface morphology of the films were observed by Scanning Electron Microscope (SEM). Using this techniques, we specify the effect of stannous chloride concentration and weight ratio of urea/H2O on the crystallinity and morphology of these films. The rutile structure corresponding (110), (101) and (211) planes of SnO2 is obtained. The increasing of stannous chloride concentration and the decreasing weight ratio of urea/H2O is found to improve the crystallinity of the film. The average diameter of grain size is about 96 nm.
2018 International Conference on ICT for Rural Development (IC-ICTRuDev), 2018
In this paper, we report the initial study to design and development of long-range wireless commu... more In this paper, we report the initial study to design and development of long-range wireless communication system based on LoRa technology for Indonesian fishermen in which the targeted ship is under <5 GT (small-ship category). The developed system consists of 1) customizable end-node; 2) Android apps equipped in a smartphone as a user interface (namely e-Nelayan app); 3) gateway; 4) and a server application for online monitoring purpose. The e-Nelayan app covers three features: the SOS button, chat, and recent weather information. While the end-node part includes Bluetooth module, Microcontroller, Long-range radio module, power regulator circuit, and Li-Po battery for main supply, all of them are packed based on the consumer product. The discussion of this paper focuses on a) the brief description of the proposed system; b) the profile of developed android app, c) and anatomy of the hardware. Moreover, the tests (both for laboratory test and field test) also have been observed. Since the proposed system is an initial study, hence we conduct on the demo of ‘ping connection’ in lab scale test. While for the field test, we used RSSI analysis and object tracker test.