Directory of Open Access Journals (DOAJ)
Lawrence A. Shepp, Sushanta Srivastava,
... two shuttle-launched spacecraft, the Westar IV and Palapa B2 satellites, failed to reach orbit when their ... Challenger had observed the premature extinction of the Palapa PKM.
Tópico(s): Atomic and Subatomic Physics Research
1986 - Institute of Electrical and Electronics Engineers | AT&T Technical Journal
Ucuk Darusalam, Fitri Yuli Zulkifli, Purnomo Sidi Priambodo, Eko Tjipto Rahardjo,
... that are implemented as a backbone on the Palapa Ring network has an opportunity to be expanded ...
Tópico(s): Optical Wireless Communication Technologies
2020 - Institute of Advanced Engineering and Science (IAES) | Bulletin of Electrical Engineering and Informatics
Tópico(s): Public Procurement and Policy
2020 - IJSTR | International journal of scientific and technology research
Tarmizi Taher, Yudha Gusti Wibowo, Sena Maulana, Neza Rahayu Palapa, Aditya Rianjanu, Aldes Lesbani,
Biochar has gained considerable attention as a promising material for CO2 adsorption. Herein, cellulose-derived biochar (CBC) has been modified by incorporating layered double oxides (LDO) to enhance its sorption capacity toward CO2 molecules. Several characterization methods, including scanning electron microscopy (SEM), X-ray diffractometer (XRD), and Fourier transform infrared (FTIR) spectroscopy analysis, have been conducted to investigate the effect of LDO loading on the obtained composite characteristics. ...
Tópico(s): Phase Equilibria and Thermodynamics
2023 - Elsevier BV | Materials Letters
Tarmizi Taher, Andika Munandar, Nurul Mawaddah, M. Syamsuddin Wisnubroto, Patimah Mega Syah Bahar Nur Siregar, Neza Rahayu Palapa, Aldes Lesbani, Yudha Gusti Wibowo,
Composite material based on montmorillonite – mixed metal oxides (MMT_MMO) derived from ZnAl layered double hydroxides was successfully synthesized by facile co-precipitation method under the presence of montmorillonite suspension followed by calcination at 400 °C. The as-synthesized material was characterized by several characterization techniques, including XRD, FTIR, SEM, TEM, TGA, and BET, then tested as an adsorbent for removal of both methylene blue (MB) as a cationic dye and congo red (CR) as the ...
Tópico(s): Nanomaterials for catalytic reactions
2022 - Elsevier BV | Inorganic Chemistry Communications
Alfan Wijaya, Patimah Mega Syah Bahar Nur Siregar, Aldi Priambodo, Neza Rahayu Palapa, Tarmizi Taher, Aldes Lesbani,
Innovative modification of Cu-Al/C composites was synthesized by coprecipitation method at pH 10 and added biochar (BC) and graphite (GF) to form Cu-Al/BC and Cu-Al/GF composites. Pristine and composites were characterized by XRD, FT-IR, Thermalgravimetric, and surface area using the BET method. The XRD diffraction and FTIR spectrum of Cu-Al/BC and Cu-Al/GF showed that the composite material from LDH, biochar, and graphite was successfully prepared. Modified LDH were surface area higher than the pristine, ...
Tópico(s): Graphene and Nanomaterials Applications
2021 - ARTS Publishing Corp. | Science & Technology Indonesia
Novie Juleanti, Neza Rahyu Palapa, Tarmizi Taher, Nurlisa Hidayati, Bunga Indah Putri, Aldes Lesbani,
The development of layered double hydroxide materials into composites with carbon-based materials in the form of CaAl-Biochar and MgAl-Biochar has been successfully carried out. The success parameters of the preparation process include XRD, FT-IR, Adsorption-Desorption N2, SEM, and TG-DTA. The success through XRD is evidenced by the appearance of the typical diffraction peaks of double-layer hydroxy around 2???? = 11°(003), 20°(006), and 60°(113). In addition, there is diffraction around 22°(002) ...
Tópico(s): Geochemistry and Elemental Analysis
2021 - ARTS Publishing Corp. | Science & Technology Indonesia
Normah Normah, Novie Juleanti, Patimah Mega Syah Bahar Nur Siregar, Alfan Wijaya, Neza Rahayu Palapa, Tarmizi Taher, Aldes Lesbani,
Modification of the layered double hydroxide of CuAl-LDHs by composite with hydrochar (HC) to form CuAl-HC LDH. Material characterization by XRD, FT-IR and SEM analysis was used to prove the success of the modification. The characterization of XRD and FT-IR spectra showed similarities to pure LDH and HC. Selectivity experiments were carried out by mixing malachite green, methylene blue, rhodamine-B, methyl orange, and methyl red to produce the most suitable methyl blue dye for CuAl-LDH, HC and CuAl- ...
Tópico(s): Nanomaterials for catalytic reactions
2021 - Diponegoro University | BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS
Aldes Lesbani, Neza Rahayu Palapa, Rabelia Juladika Sayeri, Tarmizi Taher, Nurlisa Hidayati,
Ni/Al layered double hydroxide was used as a starting material for composite formation with biochar as a matrix. The materials were characterized using X-ray, FTIR, nitrogen adsorption-desorption, thermal, and morphology analyses. The NiAl LDH/Biochar material is then used as an adsorbent of methylene blue from an aqueous solution. The factor that was influencing adsorption such as pH, time, methylene blue concentration, and temperature adsorption was studied systematically. The regeneration of ...
Tópico(s): Layered Double Hydroxides Synthesis and Applications
2021 - Gadjah Mada University | Indonesian Journal of Chemistry
Tarmizi Taher, Raden Putra, Neza Rahayu Palapa, Aldes Lesbani,
Magnetite-nanoparticle-decorated NiFe LDH ([email protected] LDH) has been synthesized by the coprecipitation method followed by subsequent hydrothermal treatment. Material characterization was conducted using XRD, FTIR, SEM, BET surface area, and TG-DTA. [email protected] LDH exhibited high crystallinity, where the MNPs are uniformly distributed on its surface. [email protected] LDH showed higher adsorption capacity for congo red dye removal from an aqueous solution (79.6 mg/g). A further adsorption ...
Tópico(s): Adsorption and biosorption for pollutant removal
2021 - Elsevier BV | Chemical Physics Letters
Risfidian Mohadi, Neza Rahayu Palapa, Aldes Lesbani,
Widely reports have evaluated the use of biochar (BC) composites to layered double hydroxide (LDH) to adsorb dyes from wastewater. However, its applicability for adsorbing a mixture of cationic dyes such as Malachite green (MG), Rodhamine-B (Rh-B), and Methylene blue (MB), which causes carcinogenic and mutagenic effects on aquatic life, has not been studied. In this work, we compared the performance of CaAl-LDH/BC adsorbent with or without the addition of BC in the adsorption of cationic dyes. The adsorption ...
Tópico(s): Advanced Photocatalysis Techniques
2021 - Diponegoro University | BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS
Arini Fousty Badri, Patimah Mega Syah Bahar Nur Siregar, Neza Rahayu Palapa, Risfidian Mohadi, Mardiyanto Mardiyanto, Aldes Lesbani,
Mg-Al-layered double hydroxide (LDH) was fabricated using a coprecipitation method at pH 10. Thereafter, Mg-Al-LDH was impregnated with biochar to manufacture a Mg-Al/Biochar composite. The composite was characterized using powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, N2 adsorption—desorption, thermogravimetry-differential thermal analysis (TG-DTA), and scanning electron microscopy (SEM) experiments, and was subsequently used for malachite green (MG) adsorption. MG adsorption ...
Tópico(s): Phosphorus and nutrient management
2021 - Diponegoro University | BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS
Neza Rahayu Palapa, Tarmizi Taher, Alfan Wijaya, Aldes Lesbani,
Modification of Cu/Cr layered double hydroxides (LDHs) has been conducted by intercalation using Keggin type polyoxometalate [a-SiW12O40]4- to form CuCr-[a-SiW12O40]. The materials were analyzed by XRD, FTIR, and surface area analyses. Furthermore, materials were used as selectivity adsorbents of cationic dyes such as malachite green, rhodamine-B and methylene blue. The malachite green is more selective than others from an aqueous solution. The adsorption of malachite green showed that the adsorption ...
Tópico(s): Layered Double Hydroxides Synthesis and Applications
2021 - ARTS Publishing Corp. | Science & Technology Indonesia
Patimah Mega Syah Bahar Nur Siregar, Neza Rahayu Palapa, Alfan Wijaya, Erni Salasia Fitri, Aldes Lesbani,
In this research, Ni/Al layered double hydroxide (LDH) was modified by using co-precipitation method to generate Ni/Al-graphite (Ni/Al-GF) and Ni/Al-biochar (Ni/Al-BC). The adsorbents were applied to remove Congo Red from aqueous solution. The obtained samples were characterized by using XRD, FTIR, BET and TG-DTA. The XRD diffraction pattern of Ni/Al LDH, Ni/Al-GF, and Ni/Al-BC presented the formation of composite with decreasing crystallinity. The surface area modified LDHs was higher than the pristine ...
Tópico(s): Dye analysis and toxicity
2021 - ARTS Publishing Corp. | Science & Technology Indonesia
Normah Normah, Neza Rahayu Palapa, Tarmizi Taher, Risfidian Mohadi, Hasja Paluta Utami, Aldes Lesbani,
In this research, NiAl-LDH was synthesized using the coprecipitation method and modified with biochar and graphite to produce NiAl-biochar and NiAl-graphite composite materials. The adsorbent that has been synthesized is used for the application of adsorption of Fe(II) ions in aqueous solution. The resulting material was characterized by XRD (X-ray Diffraction) analysis, spectrophotometer FT-IR, BET analysis for determine the specific surface area and TG-DTA analysis. XRD diffractogram showed that ...
Tópico(s): Extraction and Separation Processes
2021 - ARTS Publishing Corp. | Science & Technology Indonesia
Neza Rahayu Palapa, Risfidian Mohadi, Addy Rachmat, Aldes Lesbani,
Layered double hydroxide (LDH) Cu/Al and Cu/Cr had been used as adsorbent of malachite green (MG) in aqueous solution. The properties of Cu/Al and Cu/Cr LDHs were analyzed by X-ray diffraction, surface area analysis (BET) and FTIR spectroscopy. Adsorption study of MG was achieved at pH 9. Adsorption of MG follows the pseudo-second-order kinetic model. Langmuir isotherm was suitable for adsorption of MG on both LDH with a maximum adsorption capacity of 59.52 mg/g. The thermodynamic study indicated that ...
Tópico(s): Nanomaterials for catalytic reactions
2020 - Med Journals Editions | Mediterranean Journal of Chemistry
Neza Rahayu Palapa, Novie Juleanti, Normah, Risfidian Mohadi, Tarmizi Taher, Addy Rachmat, Aldes Lesbani,
The preparation of a copper aluminum/biochar composite and its application for the adsorption of procion red dye was studied. The composite materials were prepared by a co-precipitation method and characterised by X-ray diffraction, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller surface area analysis, scanning electron microscopy, and thermogravimetry. The results of the adsorption study show that adsorption on the copper aluminum/biochar composite follows pseudo-second-order kinetics, ...
Tópico(s): Layered Double Hydroxides Synthesis and Applications
2020 - Japan Society on Water Environment | Journal of Water and Environment Technology
Aldes Lesbani, Tarmizi Taher, Neza Rahayu Palapa, Risfidian Mohadi, Addy Rachmat, Mardiyanto Mardiyanto,
The Ni–Fe layered double hydroxide (LDH) intercalated by Keggin-type polyoxometalate (POM) of SiW12O404− was investigated for the first time. The synthesized Ni–Fe LDH and Ni–Fe POM were characterized by XRD, FT-IR, and N2 adsorption–desorption isotherm to identify the intercalation process as well as their surface morphology. The obtained results indicated that after intercalated by POM, the interlayer distance of the LDH expanded due to the insertion of POM anion and removal of some native NO3− ...
Tópico(s): Adsorption and biosorption for pollutant removal
2020 - Springer Nature | SN Applied Sciences
Neza Rahayu Palapa, Novie Juleanti, Normah Normah, Tarmizi Taher, Aldes Lesbani,
Cu-Al layered double hydroxide (LDH) was intercalated with Keggin ion of polyoxometalate K4[a-SiW12O40] to form Cu-Al-SiW12O40 LDH. The obtained materials were analyzed by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR) spectroscopy, and Brunaur-Emmett-Teller (BET) surface area analysis. Furthermore, the materials were used as adsorbents of malachite green from aqueous solution. Some variables for adsorption, such as: effect of adsorption times, malachite green concentration, and also adsorption ...
Tópico(s): Adsorption and biosorption for pollutant removal
2020 - Diponegoro University | BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS
Neza Rahayu Palapa, Tarmizi Taher, Bakri Rio Rahayu, Risfidian Mohadi, Addy Rachmat, Aldes Lesbani,
The preparation of CuAl LDH and biochar (BC) composite derived from rice husk and its application as a low-cost adsorbent for enhanced adsorptive removal of malachite green has been studied. The composite was prepared by a one-step coprecipitation method and characterized by X-ray Diffraction (XRD), Fourier Transform Infra Red (FTIR), Brunauer-Emmett-Teller (BET), and Scanning Electron Microscopy - Energy Dispersive X-ray (SEM−EDX). The result indicated that CuAl LDH was successfully incorporated with ...
Tópico(s): Nanomaterials for catalytic reactions
2020 - Diponegoro University | BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS
Melantina Oktrianty, Neza Rahayu Palapa, Risfidian Mohadi, Aldes Lesbani,
Zn/Cr and Zn/Cr layered double hydroxides (LDHs) intercalated with Keggin ion [α-SiW 12 O 40 ] 4-were successfully synthesized at room temperature and pH value of 10.The synthesized materials were characterized by means of the XRD, BET, and FT-IR analyses and used as an adsorbent iron(II).The adsorption process was investigated by studying pH, the kinetics, and thermodynamic properties of the adsorption process.The results showed the interlayer Zn/Cr LDHs was 7.53 Å and increase to 10.26 Å on Zn/Cr ...
Tópico(s): Layered Double Hydroxides Synthesis and Applications
2020 - Polish Society of Ecological Engineering | Journal of Ecological Engineering
Neza Rahayu Palapa, Yosi Saria, Tarmizi Taher, Risfidian Mohadi, Aldes Lesbani,
Layered double hydroxides are composed by substitution of metal cation divalent and trivalent. Metal cation divalent and trivalent can be changed. In this work, effect metal cation trivalent (M 3+ ) toward layer formation were studied. Synthesis of LDHs has used co-precipitation methods with molar ratio 3:1 and kept pH at 10. The result of synthesis was characterized by X-ray Diffraction (XRD) and Fourier Transform Infrared (FT-IR) analyses.
Tópico(s): Mesoporous Materials and Catalysis
2019 - ARTS Publishing Corp. | Science & Technology Indonesia
Tommy Martho Palapa, Alfonds Andrew Maramis,
Heavy metals exposed to the environment as a result of Talawaan–Tatelu mining activity (North Sulawesi, Indonesia) potentially contaminated the surrounding area. The purpose of this study was to determine the content of As, Cd, Cr, Cu, Ni, Pb, Zn, and Hg in water of stream near an amalgamation tailing pond in Talawaan–Tatelu mining. The metals were determined using ICP/MS, except Hg using CVAFS method. In general, the metals content in water of stream near Talawaan–Tatelu mining is higher than one ...
Tópico(s): Mining and Resource Management
2015 - Elsevier BV | Procedia Chemistry
... T-More Hotel and Lounge. KFC Flobamora Mall, Palapa Resto and Café, Dapur Nekamese are the best ...
Tópico(s): Edcuational Technology Systems
2015 - Elsevier BV | Procedia Computer Science
... J., Nardiyono, L. M. Engström, B. Pamungkas, J. Palapa, E. Meijaard, and S. A. Stanley. 2006. The ...
Tópico(s): Wildlife Ecology and Conservation
2010 - Wiley | Biotropica
The Caribbean Palms Resort has attempted to achieve both revenue and guest satisfaction from its beach-front palapas. However, the approaches to date have been too complex and have confused customers. A straightforward policy of charging appropriate seasonal prices for all palapas, coupled with add-on services for those who want them, will achieve both revenue and guest-satisfaction goals.
Tópico(s): Diverse Aspects of Tourism Research
2006 - SAGE Publishing | Cornell Hotel and Restaurant Administration Quarterly
... guest confrontations while boosting both guest satisfaction and palapa revenue. A particularly effective approach might be to ...
Tópico(s): Maritime Ports and Logistics
2006 - SAGE Publishing | Cornell Hotel and Restaurant Administration Quarterly
Andrew J. Marshall, Nardiyono, Linda M. Engström, Bhayu Pamungkas, Jhon Palapa, Erik Meijaard, S. Stanley,
Due to its practical relevance to conservation, considerable efforts have been devoted to understanding the effects of logging on orangutan (Pongo spp.) population densities. Despite these efforts, consistent patterns have yet to emerge. We conducted orangutan nest surveys and measured forest quality and disturbance level at 108 independent locations in 22 distinct sites in the forests of the Berau and East Kutai regencies of East Kalimantan, Indonesia. Survey locations varied substantially in orangutan ...
Tópico(s): Animal Behavior and Reproduction
2006 - Elsevier BV | Biological Conservation
... the first countries to launch a civilian satellite, Palapa, in 1976 and to place a television set ( ...
Tópico(s): Asian Culture and Media Studies
2006 - Routledge | Asian Journal of Communication