The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extr... more The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extraction of salmeterol xinafoate (SLX) from serum was studied. SLX is an acting β-adrenergic receptor agonist used in the treatment of asthma and has an athletic performance-enhancing effect. Molecular dynamics were used for the simulation of the SLX-imprinted pre-polymerization system, to determine the stability of the system. The computational simulation showed that SLX as a template, 4-hydroxyethyl methacrylate (HEMA) as a monomer, and trimethylolpropane trimethacrylate (TRIM) as a crosslinker in mol ratio of 1:6:20 had the strongest interaction in terms of the radial distribution functional. To validate the computational result, four polymers were synthesized using the precipitation polymerization method, and MIP with composition and ratio corresponding with the system with the strongest interaction as an MD simulation result showed the best performance, with a recovery of 96.59 ± 2.24...
Jurnal Pengabdian kepada Masyarakat (Indonesian Journal of Community Engagement), May 6, 2019
Kata kunci: resistivitas; rawan longsor; penyuluhan Abstrak Wilayah Desa Cisempur terletak di ler... more Kata kunci: resistivitas; rawan longsor; penyuluhan Abstrak Wilayah Desa Cisempur terletak di lereng Gunung Geulis dengan topografi yang bervariasi. Perubahan fungsi lahan hutan menjadi komplek perumahan terus berjalan seiring dengan bertambahnya kebutuhan areal pemukiman. Kemiringan lereng, pengurangan vegetasi, dan penambahan beban bangunan menjadikan daerah ini berpotensi rawan longsor. Untuk mengetahui tingkat kestabilan dan daya dukung lahan, maka perlu dilakukan pengkajian kondisi perlapisan batuan bawah permukaan. Penelitian ini membahas tentang struktur resistivitas dangkal yang diperoleh melalui teknik Electrical Resistivity Tomography (ERT) pada dua lintasan pengukuran. Pengolahan data menggunakan metode inversi dua dimensi (2D) sehingga diperoleh penampang yang menggambarkan perlapisan batuan berdasarkan nilai resistivitasnya. Interpretasi terhadap kedua penampang mengindikasikan keberadaan lapisan pasir yang berasosiasi dengan akuifer dan lempung tufaan yang dapat berperan sebagai bidang gelincir. Hasil pendugaan juga menunjukkan bahwa semakin kearah komplek perumahan terdapat kecenderungan penurunan daya dukung lahan yang diindikasikan oleh pergeseran tanah. Sosialisasi hasil pendugaan dilakukan melalui penyuluhan untuk meningkatkan pemahaman sehingga menyadarkan masyarakat Desa Cisempur terhadap potensi sekaligus mitigasi bencana pergerakan tanah.
Southeast Asia is situated at the junction of four major tectonic plates (Eurasian, Indian–Austra... more Southeast Asia is situated at the junction of four major tectonic plates (Eurasian, Indian–Australian, Pacific, and Philippine Sea) and a few smaller microplates, hence it is one of the regions with the most complicated geological histories on our planet. It is an area which includes a broad spectrum of fascinating geological formations and structures, spanning from the Precambrian till today, active tectonics with some of the highest mountains of Earth, volcanic activity, and an immense supply and deposition of sediments into its basins. The region of Southeast Asia has attracted the attention of researchers with diverse expertise and the amount of research outputs shows an increasing trend in the last few years, as in the past geological research was unfavorable, due to the occurrence of extensive rainforests and unexplored areas and hence limited accessibility. This geoscientific diversity hosts some of the most important economic deposits and formations on Earth thus making the ...
Molecularly imprinted polymer (MIP) computational design is expected to become a routine techniqu... more Molecularly imprinted polymer (MIP) computational design is expected to become a routine technique prior to synthesis to produce polymers with high affinity and selectivity towards target molecules. Furthermore, using these simulations reduces the cost of optimizing polymerization composition. There are several computational methods used in MIP fabrication and each requires a comprehensive study in order to select a process with results that are most similar to properties exhibited by polymers synthesized through laboratory experiments. Until now, no review has linked computational strategies with experimental results, which are needed to determine the method that is most appropriate for use in designing MIP with high molecular recognition. This review will present an update of the computational approaches started from 2016 until now on quantum mechanics, molecular mechanics and molecular dynamics that have been widely used. It will also discuss the linear correlation between comput...
Clean silica surfaces have a high surface energy. In consequence, colliding silica nanoparticles ... more Clean silica surfaces have a high surface energy. In consequence, colliding silica nanoparticles will stick rather than bounce over a wide range of collision velocities. Often, however, silica surfaces are passivated by adsorbates, in particular water, which considerably reduce the surface energy. We study the effect of surface hydroxylation on silica nanoparticle collisions by atomistic simulation, using the REAX potential that allows for bond breaking and formation. We find that the bouncing velocity is reduced by more than an order of magnitude compared to clean nanoparticle collisions.
IOP Conference Series: Earth and Environmental Science
The main problem in marine seismic exploration are multiples. Multiple is coherent noise appeared... more The main problem in marine seismic exploration are multiples. Multiple is coherent noise appeared by the difference of impedance between water and seabed layer which is lead to secondary reflection wave acts as new reflector source point. Multiple appearance in seismic cross section can cause misinterpretation so multiple attenuation is required. Both F-K Filter and Radon Transform methods can be used to attenuate multiple by isolating signal and noise data. Both methods have similarity in domain transform, F-K Filter transforms offset (x)-time (t) domain to frequency (f)wavenumber (K) and Radon Transform operates in τ-ρ domain to separate moveout between signal and noise. Both mehods are applied on 2D marine seismic data on Kangean waters shallow depth 200-500 meter. Radon Transform shows better result on attenuating multiple compare to F-K Filter on migrated cross section line L09 and L16. Multiple attenuation increases signal to ratio (SNR) of both line L09 and L16 which lead to more accurate in interpretation.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2012
We present experimental and molecular-dynamics simulation results of the sputtering of a Si surfa... more We present experimental and molecular-dynamics simulation results of the sputtering of a Si surface by 2 keV Ar ions. Results on both the monomer and dimer distributions are presented. In simulation, these distributions follow a generalized Thompson law with power exponent n ¼ 2 and n ¼ 3, respectively. The experimental data, obtained via plasma post-ionization in an SNMS (secondary neutral mass spectrometry) apparatus, show good agreement with respect to the dimer fraction, and the relative energy distributions of dimers and monomers. The consequences for the dimer sputtering mechanism are discussed.
The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extr... more The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extraction of salmeterol xinafoate (SLX) from serum was studied. SLX is an acting β-adrenergic receptor agonist used in the treatment of asthma and has an athletic performance-enhancing effect. Molecular dynamics were used for the simulation of the SLX-imprinted pre-polymerization system, to determine the stability of the system. The computational simulation showed that SLX as a template, 4-hydroxyethyl methacrylate (HEMA) as a monomer, and trimethylolpropane trimethacrylate (TRIM) as a crosslinker in mol ratio of 1:6:20 had the strongest interaction in terms of the radial distribution functional. To validate the computational result, four polymers were synthesized using the precipitation polymerization method, and MIP with composition and ratio corresponding with the system with the strongest interaction as an MD simulation result showed the best performance, with a recovery of 96.59 ± 2.24...
Jurnal Pengabdian kepada Masyarakat (Indonesian Journal of Community Engagement), May 6, 2019
Kata kunci: resistivitas; rawan longsor; penyuluhan Abstrak Wilayah Desa Cisempur terletak di ler... more Kata kunci: resistivitas; rawan longsor; penyuluhan Abstrak Wilayah Desa Cisempur terletak di lereng Gunung Geulis dengan topografi yang bervariasi. Perubahan fungsi lahan hutan menjadi komplek perumahan terus berjalan seiring dengan bertambahnya kebutuhan areal pemukiman. Kemiringan lereng, pengurangan vegetasi, dan penambahan beban bangunan menjadikan daerah ini berpotensi rawan longsor. Untuk mengetahui tingkat kestabilan dan daya dukung lahan, maka perlu dilakukan pengkajian kondisi perlapisan batuan bawah permukaan. Penelitian ini membahas tentang struktur resistivitas dangkal yang diperoleh melalui teknik Electrical Resistivity Tomography (ERT) pada dua lintasan pengukuran. Pengolahan data menggunakan metode inversi dua dimensi (2D) sehingga diperoleh penampang yang menggambarkan perlapisan batuan berdasarkan nilai resistivitasnya. Interpretasi terhadap kedua penampang mengindikasikan keberadaan lapisan pasir yang berasosiasi dengan akuifer dan lempung tufaan yang dapat berperan sebagai bidang gelincir. Hasil pendugaan juga menunjukkan bahwa semakin kearah komplek perumahan terdapat kecenderungan penurunan daya dukung lahan yang diindikasikan oleh pergeseran tanah. Sosialisasi hasil pendugaan dilakukan melalui penyuluhan untuk meningkatkan pemahaman sehingga menyadarkan masyarakat Desa Cisempur terhadap potensi sekaligus mitigasi bencana pergerakan tanah.
Southeast Asia is situated at the junction of four major tectonic plates (Eurasian, Indian–Austra... more Southeast Asia is situated at the junction of four major tectonic plates (Eurasian, Indian–Australian, Pacific, and Philippine Sea) and a few smaller microplates, hence it is one of the regions with the most complicated geological histories on our planet. It is an area which includes a broad spectrum of fascinating geological formations and structures, spanning from the Precambrian till today, active tectonics with some of the highest mountains of Earth, volcanic activity, and an immense supply and deposition of sediments into its basins. The region of Southeast Asia has attracted the attention of researchers with diverse expertise and the amount of research outputs shows an increasing trend in the last few years, as in the past geological research was unfavorable, due to the occurrence of extensive rainforests and unexplored areas and hence limited accessibility. This geoscientific diversity hosts some of the most important economic deposits and formations on Earth thus making the ...
Molecularly imprinted polymer (MIP) computational design is expected to become a routine techniqu... more Molecularly imprinted polymer (MIP) computational design is expected to become a routine technique prior to synthesis to produce polymers with high affinity and selectivity towards target molecules. Furthermore, using these simulations reduces the cost of optimizing polymerization composition. There are several computational methods used in MIP fabrication and each requires a comprehensive study in order to select a process with results that are most similar to properties exhibited by polymers synthesized through laboratory experiments. Until now, no review has linked computational strategies with experimental results, which are needed to determine the method that is most appropriate for use in designing MIP with high molecular recognition. This review will present an update of the computational approaches started from 2016 until now on quantum mechanics, molecular mechanics and molecular dynamics that have been widely used. It will also discuss the linear correlation between comput...
Clean silica surfaces have a high surface energy. In consequence, colliding silica nanoparticles ... more Clean silica surfaces have a high surface energy. In consequence, colliding silica nanoparticles will stick rather than bounce over a wide range of collision velocities. Often, however, silica surfaces are passivated by adsorbates, in particular water, which considerably reduce the surface energy. We study the effect of surface hydroxylation on silica nanoparticle collisions by atomistic simulation, using the REAX potential that allows for bond breaking and formation. We find that the bouncing velocity is reduced by more than an order of magnitude compared to clean nanoparticle collisions.
IOP Conference Series: Earth and Environmental Science
The main problem in marine seismic exploration are multiples. Multiple is coherent noise appeared... more The main problem in marine seismic exploration are multiples. Multiple is coherent noise appeared by the difference of impedance between water and seabed layer which is lead to secondary reflection wave acts as new reflector source point. Multiple appearance in seismic cross section can cause misinterpretation so multiple attenuation is required. Both F-K Filter and Radon Transform methods can be used to attenuate multiple by isolating signal and noise data. Both methods have similarity in domain transform, F-K Filter transforms offset (x)-time (t) domain to frequency (f)wavenumber (K) and Radon Transform operates in τ-ρ domain to separate moveout between signal and noise. Both mehods are applied on 2D marine seismic data on Kangean waters shallow depth 200-500 meter. Radon Transform shows better result on attenuating multiple compare to F-K Filter on migrated cross section line L09 and L16. Multiple attenuation increases signal to ratio (SNR) of both line L09 and L16 which lead to more accurate in interpretation.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2012
We present experimental and molecular-dynamics simulation results of the sputtering of a Si surfa... more We present experimental and molecular-dynamics simulation results of the sputtering of a Si surface by 2 keV Ar ions. Results on both the monomer and dimer distributions are presented. In simulation, these distributions follow a generalized Thompson law with power exponent n ¼ 2 and n ¼ 3, respectively. The experimental data, obtained via plasma post-ionization in an SNMS (secondary neutral mass spectrometry) apparatus, show good agreement with respect to the dimer fraction, and the relative energy distributions of dimers and monomers. The consequences for the dimer sputtering mechanism are discussed.
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Papers by Yudi Rosandi